250 results
Search Results
2. Cycloidal Magnetic Gear Combining Axial and Radial Topologies.
- Author
-
Duan, Godwin, Gupta, Tanish, Sutton, Edward, Wang, Matthew, Gardner, Matthew C., Khan, Salek A., and Praslicka, Bryton
- Subjects
- *
MAGNETISM , *TORQUE control , *GEARING machinery , *TOPOLOGY - Abstract
Axial flux and radial flux cycloidal permanent magnetic gears are characterized by high gear ratios and high torque densities; however, their rotors experience large unbalanced forces, which stress the bearings used in the gear. This paper presents a new cycloidal magnetic gear topology that combines the radial and axial flux topologies. The paper analyzes the forces and torques contributed by the axial and radial magnets in this topology using 3D finite element analysis. It was found that the perpendicular force is necessary to transfer torque to the high-speed shaft and, thus, cannot be cancelled out, but the eccentric component of the magnetic forces can be largely cancelled out, potentially reducing bearing losses and increasing the lifespan of the bearings used in the gear. A proof-of-concept prototype was constructed. Experimental slip torque results matched 3D finite element analysis (FEA) simulations to within 15%, and testing showed that no-load losses were reduced and the slip torque was increased by combining both axial and radial topologies, compared to using an axial configuration alone. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
3. An Improved Subdomain Model for Predicting the Magnetic Field of a Motor Containing Non-Orthogonal Boundaries.
- Author
-
Dong, Lieyi, Li, Wanyou, and Shuai, Zhijun
- Subjects
- *
MAGNETIC fields , *PERMANENT magnets , *PERMANENT magnet motors , *AIR gap flux , *ACTINIC flux , *FINITE element method - Abstract
In this paper, the boundary discretization method is used to improve the traditional subdomain model. The improved model can be used to calculate the magnetic field distribution in the region containing non-orthogonal boundary, avoiding the influence of the simplified stator slot or permanent magnet shape on the results in calculating the motor magnetic field using the traditional subdomain model. In addition, the improved subdomain model can also be used to calculate the air-gap flux density when the rotor is eccentric, instead of segmenting the air-gap to an equivalent state without eccentricity. The calculation object of this paper is a surface-mount permanent magnet motor with a rectangular stator slot. The air-gap flux density under no-load and load conditions is calculated, respectively. Since the improved subdomain model does not need to simplify the stator slot shape, the magnetic potential in the stator slot is also calculated. Finally, the air-gap flux density under rotor eccentricity is calculated, and the influence of the calculating parameters on the results of the improved subdomain model is discussed. All the calculated results are compared with those obtained by the finite element method, which verifies the accuracy of the improved calculation model. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
4. Distributed Optimal Control of DC Microgrid Considering Balance of Charge State.
- Author
-
Huang, Bonan, Zheng, Shun, Wang, Rui, Wang, Huan, Xiao, Jiangfang, and Wang, Peng
- Subjects
- *
ROBUST control , *MICROGRIDS , *ENERGY storage - Abstract
State-of-charge (SoC) imbalance and bus voltage deviation are two of the main problems in autonomous dc microgrids. Based on this concern, this paper presents an improved dual-quadrant SoC weighted control strategy and a distributed optimization control method to achieve SoC balance, ensuring accurate power-sharing and bus voltage recovery. Firstly, this paper couples the injected/released power with the current SoC and observed average SoC value to weight the droop coefficient, which is based on the charge/discharge mode for the energy storage system. Then a secondary controller is designed based on distributed optimal control to eliminate the bus voltage deviation caused by the line impedance difference. The proposed optimal control method optimizes the average bus voltage to the nominal value and achieve accurate power-sharing by constructing the correlated variables and voltage independent intermediate variables exchanged among bulk energy storage units (ESUs). Since the voltage observer cannot accurately observe the true average bus voltage under the communication delay, the proposed distributed optimal control method without the voltage observer can ensure that the average bus voltage is optimized to the nominal value, thus improving the robustness of the control system. Finally, the correctness and effectiveness of the proposed method are verified in Simulink/MATLAB. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
5. Modelling of Wind Turbine Operation for Enhanced Power Electronics Reliability.
- Author
-
Ahmedi, Arsim, Barnes, Mike, Levi, Victor, Carmona Sanchez, Jesus, Ng, Chong, and McKeever, Paul
- Subjects
- *
RELIABILITY of electronics , *POWER electronics , *WIND turbines , *THERMOCYCLING , *BIPOLAR transistors - Abstract
Enhancing power electronics (PE) converter reliability is crucial for ensuring a reliable operation of current and future operating Wind Turbines (WTs). Achieving high reliability of variable speed WT PE systems requires careful consideration of their operation, and particularly their thermal cycling. This paper presents a methodology for evaluating and reconsidering operational strategies of WTs with relation to the thermal loading and lifetime consumption of the converter. The methodology is applied to compare control strategies for the WT generator and evaluate their impact on the converter reliability by observation of the thermal cycles and by calculating the resultant lifetime consumption of those stress cycles. The thermal stress on both the Machine Side Converter (MSC) and the Grid Side Converter (GSC) is examined and compared. It is shown that the least reliable of the three evaluated control strategies is the one that tracks the power curve below rated speed most closely. This paper suggests that dynamic transients associated with the WT control largely influence the IGBT module wear-out and their modelling needs to be prioritized for lifetime studies. These dynamic transients are captured by the improved model whose value is confirmed for the comparisons in the case study of the paper. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. Current Distortion Rejection in PMSM Drives Using an Adaptive Super-Twisting Algorithm.
- Author
-
Garduno, Daniel, Rivas, Jaime J., Castillo, Oscar, Ortega Gonzalez, Ruben, and Gutierrez, Francisco Emilio
- Subjects
- *
PERMANENT magnet motors , *SYNCHRONOUS electric motors , *ALTERNATING current electric motors , *SPEED measurements , *ALGORITHMS - Abstract
Unavoidably, the controlsystem of any permanent magnet synchronous motor (PMSM) is subjected to perturbations, e.g., motor nonidealities and inverter nonlinearities. To reject these perturbations, a new super-twisting (ST) control variant, called speed adaptive super-twisting (S-AST) control, is proposed in this paper. In the S-AST control, a proportional-integral (PI) and a ST controllers are merged using an adaptive law that is based on the motor speed measurement. This is done to reduce the chattering problems that the standard ST control presents. In addition, a mathematical design for the S-AST control is proposed, where the relationship between the chattering amplitude, the switching frequency and the system perturbations is shown. The main contribution in this paper is the application of the S-AST controller to reduce the total harmonic distortion (THDi) of the PMSM currents. By comparing the S-AST control against PI control, the THDi is reduced from 9.9% to 1.27%, in simulation, and the THDi is reduced from 22.79% to 1.56%, experimentally. These results demonstrate how the S-AST control is an excellent alternative to improve the waveform of the PMSM currents. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
7. Application of Superconductors to Suppress Ferroresonance Overvoltage in DFIG-WECS.
- Author
-
Mosaad, Mohamed, Sabiha, Nehmdoh, Abu-Siada, Ahmed, and Taha, Ibrahim
- Subjects
- *
WIND energy conversion systems , *SUPERCONDUCTORS , *INDUCTION generators , *SUPERCONDUCTING coils , *OVERVOLTAGE , *HIGH voltages , *MATHEMATICAL optimization , *ELECTRIC current rectifiers - Abstract
While much attention was given in the literature to improve the fault ride through (FRT) capability of a doubly-fed induction generator (DFIG)-based wind energy conversion system (WECS) during various faults at the grid side, not much attention was given to investigate and improve the performance of the DFIG-WECS under ferroresonance conditions. This paper investigates the impact of ferroresonance on the overall performance of a DFIG-WECS. The paper also presents a new technique to improve the high voltage ride through capability of the investigated system under such condition. The proposed technique relies on incorporating a superconducting coil within the dc-link of the DFIG grid-side and rotor-side converters. Energy exchange between the coil and the system is controlled through regulating the duty cycle of the dc-chopper interfacing the coil with the dc-link. In this regard, a simple but yet effective proportional-integral (PI) controller is employed to regulate the dc-chopper duty cycle. Parameters of the PI controller are optimized using elephant herding optimization algorithm. Simulation results verify the effectiveness of the proposed controller in improving the overall performance of a DFIG-WECS during ferroresonance events. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
8. Calculation Model of Armature Reaction Magnetic Field of Interior Permanent Magnet Synchronous Motor With Segmented Skewed Poles.
- Author
-
An, Yuansheng, Ma, Conggan, Zhang, Nic, Guo, Yue, Degano, Michele, Gerada, Chris, Bu, Feifei, Yin, Xiangrui, Li, Qiongyao, and Zhou, Shengsen
- Subjects
- *
PERMANENT magnet motors , *MAGNETIC fields , *ARMATURES , *PERMANENT magnets , *MAGNETIC circuits , *SYNCHRONOUS electric motors , *TORQUE control , *POLISH people - Abstract
In an interior permanent magnet synchronous motor (IPMSM) with segmented skewed poles, the armature reaction magnetic field (AR-MF) changes nonlinearly due to the saturation of the rotor magnetic barrier. Meanwhile, this varies under different excitation currents. As a result, it is difficult to be calculated by means of analytical methods. In this paper, the calculation model of AR-MF of IPMSM is first established by vector superposition method, without considering the saturation effect of rotor and the slotting effect of stator. In the second step, the virtual magnetic field of the rotor is introduced to quantitatively calculate the influence of local inhomogeneous saturation on the AR-MF. The latter is derived by combining both the subdomain method and equivalent magnetic circuit method. The complex relative permeance is also introduced to establish the AR-MF accounting for the stator slotting effect. To validate the AR-MF calculation method proposed, an 8-pole 48-slot IPMSM with segmented skewed poles is considered as a case study, showing a comparison by both with finite element (FE) results and the electromagnetic torque measured on a test bench. The model proposed in this paper shows high accuracy and fast computation with respect to FE analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
9. An Effective Non-Square Matrix Converter Based Approach for Active Power Control of Multiple DGs in Microgrids: Experimental Implementation.
- Author
-
Sadooghi, Ramin, Niknam, Taher, Sheikh, Morteza, Askarpour, Mohammad, Roustaei, Mahmoud, Chabok, Alireza, and Aghaei, Jamshid
- Subjects
- *
MATRIX converters , *REACTIVE power , *DISTRIBUTED power generation , *MICROGRIDS , *CASCADE converters - Abstract
In this paper, a new modulation strategy based on the carrier-based switching strategy for the non-square direct matrix converters (MC) is proposed to control the active power of distributed generation (DG) units. In this strategy, the active power of DGs is controlled by the central input current control of the non-square direct MC independent from the voltage and frequency. Conventionally, each DG has a converter, and for supplying a load with N number of DGs, N number of converters are needed and each converter has its own modulation switching and control strategy to control the power output of each DG. Needless to say, in a microgrid with N number of DGs, the control strategy of each converter has more complex structure than that of a microgrid with one converter, and surely the former strategy entails more volume and price. Using the proposed converter in this paper, it is possible to supply a load with N number of DGs through one converter. Also, the power outputs of all DGs are controlled by a central control strategy. The proposed central control strategy is described and simulated for a typical microgrid. Experimental and simulation results validate the effectiveness of the proposed converter and the proposed strategy. The results demonstrate the applicability and efficiency of the system and verify the theoretical analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
10. Ultra-Voltage Gain Step-Up DC-DC Converter for Renewable Energy Micro-Source Applications.
- Author
-
Bekkam, Krishna and Karthikeyan, V.
- Subjects
- *
DC-to-DC converters , *RENEWABLE energy sources , *CAPACITOR switching , *MOTOR drives (Electric motors) - Abstract
In renewable energy micro-source applications, a wide range of voltage conversion of the step-up converter is an essential part to equalize the typical low voltage of micro-source with DC-bus voltage of Inverter or motor drives. In order to meet this purpose, an ultra-voltage gain step-up DC-DC converter is proposed in this paper. The proposed converter has made an arrangement of the regenerative-boost fed switched inductor and capacitor configurations. Thereby, due to such an organization of structure, the proposed converter can develop an extremely high voltage-gain even at lower duty ratios. In addition, it has the advantage of lower switching stress across all power semi-conductive diodes. Furthermore, this paper describes the steady-state analysis and comparative features of the converter with existing recent literature. Finally, to validate theoretical analysis and test the feasibility and suitability of the proposed ultra-gain converter, the experimental results were observed by a 500 W fabricated prototype. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
11. Stabilizing Sets of Current PI Controllers for IM Drives With and Without LC Filter.
- Author
-
Vaishnav, Navneet and Jain, Amit
- Subjects
- *
SQUIRREL cage motors , *CLOSED loop systems , *IDEAL sources (Electric circuits) , *PULSE width modulation - Abstract
Connection of an LC filter to the output of voltage source inverter (VSI) in squirrel cage induction motor (SQIM) drive converts the pulse-width modulated (PWM) voltages into smooth sinusoidal voltages. However, this connection may lead to closed-loop instability in the rotor flux-oriented (RFO) vector-controlled (VC) SQIM system. The closed-loop stability of the combined SQIM + LC filter (SQLC) system is complex and has not been analyzed properly in the literature. In this paper, a detailed closed-loop stability analysis of the SQLC system has been presented based on stability region (SR) and accordingly the PI gains of VC has been designed. The SR method is adopted to derive the common stability regions for the SQIM system and SQLC system. Thereby, the paper proves that connecting an LC filter in-between the VSI and the SQIM system does not always destabilize the closed-loop system. Further, for an SQLC system, the complete range of current controller gains is obtained at various operating points. The frequency-domain specifications have been used to select a proper stabilizing set and the effect of parametric variation of LC filter on the stabilizing set has also been discussed. The experimental results are provided to validate the analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
12. Transient Stability of Hybrid Power Systems Dominated by Different Types of Grid-Forming Devices.
- Author
-
He, Xiuqiang, Pan, Sisi, and Geng, Hua
- Subjects
- *
HYBRID power systems , *SYNCHRONOUS generators , *ELECTRIC transients , *HYBRID systems , *MICROGRIDS , *EQUATIONS of motion - Abstract
This paper investigates the transient stability of power systems co-dominated by different types of grid-forming (GFM) devices. Synchronous generators (SGs and VSGs) and droop-controlled inverters are typical GFM devices in modern power systems. SGs/VSGs are able to provide inertia while droop-controlled inverters are generally inertialess. The transient stability of power systems dominated by homogeneous GFM devices has been extensively studied. Regarding the hybrid system jointly dominated by heterogeneous GFM devices, the transient stability is rarely reported. This paper aims to fill this gap. It is found that the synchronization behavior of the hybrid system can be described by a second-order motion equation, resembling the swing equation of SGs. Moreover, two significant differences from conventional power systems are discovered. The first is that the droop control dramatically enhances the damping effect, greatly affecting the transient stability region. The second is that the frequency state variable exhibits a jump at the moment of fault disturbances, thus impacting the post-fault initial-state location and stability assessment. The underlying mechanism behind the two new characteristics is clarified and the impact on the transient stability performance is analyzed and verified. The findings provide new insights into transient stability of power systems hosting heterogeneous devices. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
13. Loss and Thermal Analysis for High-Speed Amorphous Metal PMSMs Using 3-D Electromagnetic-thermal Bi-Directional Coupling.
- Author
-
Tong, Wenming, Sun, Ruolan, Li, Shiqi, and Tang, Renyuan
- Subjects
- *
METALLIC glasses , *THERMAL analysis , *ELECTROMAGNETS , *MAGNETS , *TEMPERATURE distribution , *MECHANICAL properties of condensed matter , *BISMUTH - Abstract
To research the impact of temperature-dependent characteristics of windings and magnets on the electromagnetic power loss and thermal properties of high-speed (HS) interior permanent magnet synchronous machines (PMSMs), an electromagnetic-thermal bi-directional coupling method (BDCM) is proposed for water-cooled HS PMSMs considering the assembling gaps between the motor components in this paper. The electromagnetic power loss is calculated by 3-D transient finite-element method and loaded into the 3-D temperature field according to the actual loss distribution, and the materials’ properties are in turn updated according to the temperature distributions. The loss and temperature calculation results of a 15kW HS amorphous metal PMSM are calculated by two different coupling methods in the conditions of the rated-load sinusoidal supply and converter supply, and compared with the measured results in the case of converter supply. The results obtained by the BDCM are more consistent with the experiment results, verifying the superiority of the proposed analyzing method in improving the calculation accuracy of motor loss and temperature rise. In addition, the applicable conditions of the proposed method are also summarized in the paper. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
14. A Variable Inductor Controlled Single-Stage AC/DC Converter for Modular Multi-Channel LED Driver.
- Author
-
He, Qingqing, Luo, Quanming, Wei, Yuqi, and Sun, Pengju
- Subjects
- *
LIQUID crystal displays , *ELECTRIC current rectifiers , *MULTICHANNEL communication , *STREET lighting , *ZERO voltage switching , *LIGHT emitting diodes , *COST control - Abstract
Light-emitting diodes (LEDs) are widely used in street lighting, landscape lighting, liquid crystal display (LCD) backlighting, healthcare, etc. As an important part of LED lighting products, LED driver plays a vital role in maintenance costs reduction, energy saving and lifetime prolongation. In this paper, a single-stage LED driver is proposed, which is integrated by a totem-pole bridgeless power factor correction (PFC) unit and several modular LCL-T resonant rectifiers. The totem-pole bridgeless PFC unit and the LCL-T resonant rectifiers are integrated by sharing switches, which can simplify the circuit and reduce the system cost. The output current can be regulated by applying the variable inductor control. Constant duty cycle and fixed switching frequency operation can be achieved as well. The operating principle and the performance of the proposed converter are analyzed in this paper. In addition, a precise parameter design method is proposed by considering the high-order harmonics. At last, an experimental prototype is established to validate the proposed parameter design and variable inductor control method. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
15. 2-D Analytical No-Load Electromagnetic Model for Slotted Interior Permanent Magnet Synchronous Machines.
- Author
-
faradonbeh, Vahid Zamani, Rahideh, A., Taghipour Boroujeni, Samad Taghipour, and Markadeh, Gholamreza Arab
- Subjects
- *
COMPUTATIONAL electromagnetics , *MAGNETIC flux density , *ACTINIC flux , *FINITE element method , *ELECTROMAGNETIC launchers , *MAGNETIC circuits , *PERMANENT magnets - Abstract
This paper presents a fast analytical model for estimating the components of the PM flux density distribution in the air-gap for a number of interior permanent magnet synchronous machines (IPMSMs). Deriving the two-dimensional (2-D) analytical model for IPMSMs is more challenging compared to that of surface-mounted permanent magnet synchronous machines (SPMSMs) due to the inconsistent geometry of the rotor in polar coordinates. IPMSMs are usually modeled by using 0-D or 1-D methods such as the magnetic equivalent circuit (MEC); however, the MEC method is unable to take into account the tangential component of the magnetic flux density vector. In this paper, a 2-D analytical no-load electromagnetic model for five rotor topologies of IPMSMs is proposed. The effects of the stator slots on the radial component of the PM flux density distribution in the air-gap are then included by defining an air-gap function. The effects of the stator slots on the tangential components of the PM flux density distribution in the air-gap are also considered by injecting virtual surface currents (VSCs) or virtual permanent magnets (VPMs). For verification purposes, the analytical results are compared with those of the finite element method (FEM) and the experimental results of one of the cases. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
16. Finite Control Set – Model Predictive Control Based On Sliding Mode For Bidirectional Power Inverter.
- Author
-
Estrada, Leonel, Vazquez, Nimrod, Vaquero, Joaquin, Hernandez, Claudia, Arau, Jaime, and Huerta, Hector
- Subjects
- *
SLIDING mode control , *PREDICTION models , *ENERGY consumption , *COST functions , *ELECTRIC inverters , *FINITE, The - Abstract
This paper presents a different Finite Control Set – Model Predictive Control (FCS-MPC) for grid-connected three-phase bidirectional power inverters. These are typically used in dc or ac renewable-based microgrids (MGs), where bidirectional operation and fast dynamic response is required. The bidirectional grid-connected inverters are an essential part of MG, which inject energy into the ac grid or demand energy from it. The dynamic behavior of the system is a major concern since the current can suddenly change depending on the hierarchical controller. This paper proposes a different cost function using sliding mode theory, which offers a good dynamic response, reduced computational burden, and a parameter-free control model. The operation principle of the proposed controller is given and evaluated using a Hardware-In-the-Loop (HIL) system, but also experimentally with a 1kW laboratory prototype. The final results demonstrate the advantages of using this approach in grid-connected three-phase bidirectional power inverters in terms of dynamic response and reduced computational burden, making this solution technically attractive and viable. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
17. A Parameterized Linear 3D Magnetic Equivalent Circuit for Analysis and Design of Radial Flux Magnetic Gears–Part I: Implementation.
- Author
-
Johnson, Matthew, Gardner, Matthew C., and Toliyat, Hamid A.
- Subjects
- *
MAGNETIC flux , *MAGNETIC circuits , *FINITE element method , *MAGNETIC torque , *TORQUE - Abstract
Magnetic gears can perform the same function as mechanical gears with the added benefits inherent to contactless power transfer. However, quick and accurate analysis tools are required for magnetic gears to reach their full potential. As end effects can significantly impact the slip torque of a magnetic gear, 2D models often overestimate the slip torques, so 3D models are frequently required. Therefore, this paper proposes a 3D linear Magnetic Equivalent Circuit (MEC) or reluctance network model of radial flux magnetic gears with surface mounted magnets. This is an extension of a previously developed 2D MEC model, and, like the previous 2D model, it is thoroughly parametrized so that it can be directly applied to a wide range of parametric cases. This is Part I of a two-part paper and focuses on the implementation of the 3D MEC model. Part II compares the 3D MEC model against nonlinear finite element analysis (FEA) models to validate the MEC model's accuracy and to develop guidelines for discretizing the geometry. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
18. A Model Predictive Control Approach to Operation Optimization of an Ultracapacitor Bank for Frequency Control.
- Author
-
Beus, Mateo, Krpan, Matej, Kuzle, Igor, Pandzic, Hrvoje, and Parisio, Alessandra
- Subjects
- *
PREDICTION models , *PID controllers , *DYNAMIC simulation , *ALGORITHMS , *DYNAMIC models , *PREDICTIVE control systems , *REACTIVE power - Abstract
This paper presents a nonlinear dynamic simulation model of an ultracapacitor (UC) bank and the associated control system. The control system at hand consists of two levels: the lower level controls the inverter of the UC bank, while the upper control level is responsible for providing charging/discharging active power set points to be followed by the lower control level. This paper focuses on the development of the upper control level for frequency control. Specifically, two simulation case studies are developed so as to assess the performance of the proposed control framework. In the first case study the upper control level is developed using a classical Proportional-Integral-Derivative (PID) controller. In the second case study the upper control level is devised using a Model Predictive Control (MPC) algorithm based on internal linear prediction model of a nonlinear UC bank. In both cases, a nonlinear UC bank simulation model is used. The simulation case studies are modelled and tested in Matlab/Simulink. The response of the MPC-controlled UC bank is compared to the 3 existing PID-control algorithms for frequency control. The simulation results show that the MPC algorithm outperforms the conventional PID controllers. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
19. Cascaded Predictive Flux Control for a 3-L Active NPC Fed IM Drives Without Weighting Factor.
- Author
-
Xiao, Dan, Akter, Md. Parvez, Alam, Kazi, Dutta, Rukmi, Mekhilef, Saad, and Rahman, Muhammed Fazlur
- Subjects
- *
COST functions , *ALGORITHMS , *STATORS , *PREDICTION models , *VOLTAGE control - Abstract
Conventional model predictive control (MPC) for three-level active neutral point clamped converter (ANPC) utilizes weighting factors to achieve the optimal control of multiple control objectives in a single cost function. However, the selection of these weighting factors has an impact on the performance of the controlled objectives significantly. Tuning of weighting factors is usually tedious and lacks theoretical background. Moreover, the predictive and evaluation process for multiple objectives optimization have to be carried out by enumerating all admissible switching states within one loop. To simplify the complexity of this process and eliminate the effect of weighting factors, this paper proposes a cascaded predictive control scheme for a 3L-ANPC inverter fed induction machine (IM) drive. With the proposed approach, three separate cost functions for three control objectives, stator flux vector, neutral point voltage and device loss distribution are evaluated in a cascaded way, so that the optimization of these control objectives is performed independently. A 3L-ANPC inverter driven IM drive is studied in this paper to verify the effectiveness of the proposed algorithm. Experimental results in different operating conditions confirm that the proposed method achieves satisfactory steady-state and transient performances comparable to the conventional predictive control approach. The weighting factors used in the conventional method are eliminated and the computational effort is reduced by 68% compared to the conventional method without any sacrifice in the drive performance. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
20. Fuzzy Controller-Based Self-Adaptive Virtual Synchronous Machine for Microgrid Application.
- Author
-
Thomas, Vinu, S., Kumaravel, and Ashok, S.
- Subjects
- *
MICROGRIDS , *MAXIMUM power point trackers , *RENEWABLE energy sources , *FUZZY expert systems , *SELF-adaptive software , *ELECTRIC inverters , *GENETIC algorithms , *TEST systems - Abstract
Low-inertia microgrids are prone to large frequency fluctuations due to high penetration of inverter-fed renewable sources. A virtual synchronous machine (VSM) is capable of handling these frequency fluctuations. VSM imparts inertial behaviour in grid-connected inverters with the help of an electric storage device. Most of the reported VSM control schemes use a constant inertia parameter that leads to an inadequate dynamic frequency response. In this paper, a fuzzy controller-based self-adaptive VSM control scheme is proposed. Here, the value of the inertia parameter is decided using fuzzy rules which take the penetration index of renewable energy, frequency deviation and rate-of-change-of-frequency as the input parameters. These rules are formulated with the help of the sample data obtained from simulations done in MATLAB/Simulink, where the inertial parameter is optimized using a genetic algorithm for various cases. The proposed method is validated for solar photovoltaic-fed microgrid test systems using power–hardware-in-the loop and the results indicate a reduction in maximum frequency deviation compared to the constant inertia parameter based VSM schemes. The introduction of renewable energy penetration level and fuzzy expert system in modifying the inertia parameter are the novel contributions in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
21. Diagnosis of Rotor Winding Short-Circuit Fault in Multi-Phase Annular Brushless Exciter Through Stator Field Current Harmonics.
- Author
-
Hao, Liangliang, Chen, Jianlin, Li, Jiahui, Chen, Jun, He, Peng, Xiong, Guodu, Wei, Yubang, Yang, Deguang, Wang, Xiaoming, Duan, Xianwen, and Gui, Lin
- Subjects
- *
STATORS , *NUCLEAR power plants , *FAULT diagnosis , *ROTORS , *DIAGNOSIS methods - Abstract
The excitation system with a multi-phase annular brushless exciter (MPABE) is widely used in large-capacity nuclear power plants. It is of great significance to realize a reliable protection of the exciter for safe operation. Since the MPABE is adopted with rotary armature structure, the rotor winding short-circuit (RWSC) fault is very difficult to be diagnosed directly. However, it is an effective way to realize fault diagnosis through the characteristics reflected in the stator field winding. In this paper, based on the mutual induction relationship between stator current and rotor current, detailed theoretical analysis of the RWSC fault is conducted and the harmonic characteristics of the stator field current are obtained. Then, related experiments and simulations are carried out, verifying the correctness of the theoretical analysis. Finally, a diagnosis method based on the transient harmonic characteristics of the stator field current is proposed and its sensitivity is also analyzed. The diagnosis method proposed in this paper is simple and feasible, which helps to improve the safety and reliability of the MPABE system in nuclear power plants. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
22. A Novel Three-Dimensional Analytical Approach for Acoustic Noise Modeling in Switched Reluctance Machines.
- Author
-
Liang, Jianbin, Callegaro, Alan Dorneles, Bilgin, Berker, and Emadi, Ali
- Subjects
- *
NOISE , *ACOUSTIC models , *SWITCHED reluctance motors , *ACOUSTIC vibrations , *ACOUSTIC emission - Abstract
Acoustic noise modeling, analysis, and reduction are critical in the design of switched reluctance machines for noise-sensitive applications. Although the analytical method can provide a fast simulation of the acoustic noise, it is generally less accurate compared to the numerical method. In order to improve the simulation accuracy, a novel analytical method is presented in this paper. The proposed method considers the excitation of the high-axial-order vibration modes to simulate the vibration behavior and the acoustic noise in the three-dimensional (3D) domain. Methods of obtaining the input data for the 3D analytical simulations are presented. The acoustic noise results obtained from the numerical simulations and experiments from an 8/6 switched reluctance motor drive are used to validate the analytical method presented in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
23. Current Prediction Error Based Parameter Identification Method for SPMSM With Deadbeat Predictive Current Control.
- Author
-
Zhou, Ying, Zhang, Shuo, Zhang, Chengning, Li, Xueping, Li, Xuerong, and Yuan, Xin
- Subjects
- *
PARAMETER identification , *CURRENT fluctuations , *PROBLEM solving , *ALGORITHMS , *ELECTRIC inductance - Abstract
Deadbeat predictive current control (DPCC) can predict motor behavior based on SPMSM model. However, during the operation of motor system, motor parameters (such as stator inductance and flux linkage) vary frequently according to different working conditions, which may lead to controller parameter mismatch, causing current harmonic content to increase and efficiency to decrease. In order to solve these problems caused by parameter variation, first, this paper proposes a current prediction error model by considering uncertainties of model parameters. Second, stator inductance and flux linkage are decoupled based on current prediction error model, which can reduce the interaction between parameters. Finally, the Kalman Filter (KF) algorithm is presented to filter the decoupled parameters. It is shown that the stator inductance and flux linkage can be identified accurately and the complexity of computation can be simplified. The traditional DPCC method, Extended Kalman Filter (EKF) based DPCC method and the proposed DPCC method are comparatively analyzed in this paper. Simulation and experiment indicate that the proposed parameter decoupling identification method can effectively reduce current harmonic content, current fluctuation and current tracking errors caused by parameter mismatch. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
24. Reduced-Order Aggregate Model for Large-Scale Converters With Inhomogeneous Initial Conditions in DC Microgrids.
- Author
-
Wang, Rui, Sun, Qiuye, Tu, Pengfei, Xiao, Jianfang, Gui, Yonghao, and Wang, Peng
- Subjects
- *
REDUCED-order models , *DC-to-DC converters , *PRIOR learning - Abstract
In practical microgrids, the inhomogeneous initial values are widely appeared due to soft-starting operation. If traditional model order reduction approaches are applied, the input-output maps error between the original system and reduced-order system is large. To address this problem, this paper proposes a reduced-order aggregate model based on balanced truncation approach to provide the preprocessing approach for the real-time simulation of large-scale converters with inhomogeneous initial conditions in DC microgrid. Firstly, the standard linear time-invariant model with inhomogeneous initial conditions is established through non-leader multiagents concept. To end this, it is convenient for scholars to build complex system modeling with switched topology. Furthermore, the full system is divided into two components, i.e., the unforced component with nontrivial initial conditions and forced component with null initial conditions. Moreover, this paper presents an aggregated approach that involves independent reducing component responses and combining reducing component responses. Based on this, the input-output maps error is reduced. Then, the approximated error estimate of the reduced-order aggregate model regarding large-scale converters in DC microgrid is first provided, which provides prior knowledge and theoretical basis for DC microgrid designers. Finally, the simulation results illustrate the accuracy of the proposed approach. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
25. A Comparative Study of Cycloidal Reluctance Machine and Switched Reluctance Machine.
- Author
-
Fatemi, Alireza and Lahr, Derek
- Subjects
- *
RELUCTANCE motors , *SWITCHED reluctance motors , *ELECTRIC machines , *MACHINERY , *ELECTROMAGNETIC forces , *COMPARATIVE studies - Abstract
A variable reluctance electric machine with a two-degree of freedom rotor motion characterized by rotation around the center of the rotor and orbiting around the center of the stator is studied. One motivation for adopting such rotor motion would be to allow torque generation through both the radial and tangential components of the electromagnetic forces created in the airgap, as opposed to common rotary machines in which torque is a byproduct of only the tangential component of the airgap electromagnetic forces. Furthermore, the rotor motion provides a built-in gearing action similar to that of a cycloidal drive, which allows natural torque multiplication and the tight integration of the electromagnetic and mechanical systems. The two-degree of freedom rotor motion also results in a counter-intuitive inertia characteristic of this machine concept which is elaborated in this paper for the first time. Due to the reluctance nature of the torque, and because of the distinctive rotor motion profile which resembles the motion of a cycloid, the studied machine is called a cycloidal reluctance (CR) electric machine (CRM). In this paper, the principle of operation of the CRM is explained, and its performance is compared to a counterpart switched reluctance machine (SRM). A prototype is built, and the theoretical torque calculations are validated by experimental measurements. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
26. Non-Isolated n -Stage High Step-up DC-DC Converter for Low Voltage DC Source Integration.
- Author
-
Shanthi, T., Prabha, S. U., and Sundaramoorthy, Kumaravel
- Subjects
- *
DC-to-DC converters , *IDEAL sources (Electric circuits) , *VOLTAGE-frequency converters , *LOW voltage systems , *HIGH voltages , *SEMICONDUCTOR devices , *ELECTRIC current rectifiers - Abstract
The dc-dc converters with high step-up DC-voltage gain play a vital role in integrating low voltage DC sources. Though several converter topologies are reported in the recent past, attempts have been made to reduce the components, especially the switching devices, passive elements, converter losses, etc., of the converter. A novel DC-DC converter topology, viz., single switched impedance network (SSIN)-based converter with n-stage is proposed in this paper. The operation of the SSIN based converter in continuous and discontinuous conduction modes are discussed. The effect of parasitic elements on DC-voltage gain and efficiency of the SSIN is carried out. The small-signal model of the SSIN converter is derived. The performance of the SSIN converter is compared with the similar converter topologies. The 500 W prototypes of the SSIN with n = 1 and n = 2 are fabricated, and the experimental results are presented in this paper. To improve the converter performance, SiC-based semiconductor devices are used. The SSIN converter with two-stage has low switch loss at 500 W load, improved efficiency during high power and high output voltage operation, the switch stress of Vo/2, etc. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
27. BLDC Motor Drives: A Single Hall Sensor Method and a 160° Commutation Strategy.
- Author
-
Al-Adsani, Ahmad S., AlSharidah, Michel E., and Beik, Omid
- Subjects
- *
REAL-time control , *BRUSHLESS direct current electric motors , *MOTOR drives (Electric motors) , *VECTOR spaces , *DETECTORS , *PERMANENT magnet motors , *IDEAL sources (Electric circuits) - Abstract
The application of Hall-based BLDC motors ranges from automotive accessory components such as oil and water pumps to high speed compressors. This paper proposes a new twelve-step unsymmetrical 160° commutation strategy using a single Hall-effect sensor method for brushless DC (BLDC) motor drives. The signal from the Hall-effect sensor is used to generate a number of pseudo Hall signals via a proposed speed-position estimator. The pseudo signals are then employed to control switching logic of a voltage source inverter (VSI). The effectiveness of the single Hall sensor method is examined on the unconventional 160° strategy, and on conventional 120°, 150° and 180° strategies with promising results. The paper presents a detailed comparison of the twelve-step unsymmetrical 160° commutation strategy with six-step voltage space vector that is used in conventional 120° and 180° strategies, and twelve-step symmetrical voltage space vector that is used in 150° strategy. Simulation results are validated via experimental measurements on a laboratory set-up using a real time dSPACE control environment, a representative BLDC motor prototype, a VSI and associated control components. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
28. A Novel Permanent Magnet Flux-Switching Linear Motor Performance Analysis by Flexible MEC Method.
- Author
-
Naderi, Peyman and Heidary, Malihe
- Subjects
- *
PERMANENT magnets , *PERMANENT magnet motors , *MAGNETIC circuits , *FINITE element method , *DYNAMIC loads , *RELUCTANCE motors - Abstract
This paper presents a new structure of Permanent Magnet Flux-Switching Linear Motor (PM-FSLM) with a simple low weight modular primary and acceptable thrust ripple production. A flexible Magnetic Equivalent Circuit (MEC) is applied for modeling the proposed machine, which is capable to analyze the performance of different structures of PM-FSLMs. The saturation and end-effect phenomena are considered by a nonlinear permeability function and virtual zones at both ends of the machine, respectively. The machine operation under dynamic load is also investigated and its specifications are obtained. The proposed PM-FSLM has more power capability, lower current un-symmetry, and simpler mover structure compared to other ones, which can be mentioned as its benefits. Finally, the results of the proposed method are validated by the Finite Element Method (FEM) to show the effectiveness of the proposed MEC technique in terms of accuracy and processing time. The introduced linear machine and the proposed analysis method with adjustable accuracy are the paper novelties, which are presented in this work for the first time. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
29. Dynamic Thermal Model for Winding Temperature of an SRM in an Integrated Battery Charger Utilized in Electric Vehicles.
- Author
-
Rahnamaei, Sayed Reza, Nejad, Sayed Morteza Saghaian, Rashidi, Amir, and Sohankar, Ahmad
- Subjects
- *
ELECTRIC vehicle charging stations , *BATTERY chargers , *DYNAMIC models , *FINITE element method , *REDUCED-order models - Abstract
This paper presents a dynamic thermal model which predicts the winding temperature of electrical machines at steady-state and transient conditions where windings are used in integrated battery chargers (IBCs) for DC charging in a stationary position. Using winding in high current charging process causes rising winding temperature which affects insulation life. Switched reluctance machines are a proper choice for using in electric vehicles (EVs) because of their advantages such as simple and sturdy structures. IBCs can reduce volume and weight of EVs and total cost is diminished because of integration. The analytical thermal model proposed in this paper can calculates the winding temperature in balanced and unbalanced currents injection because of the phase inductance in each rotor angle is distinct, so current excitation in each phase should be different for obtaining zero total torque and keeping rotor in a stationary position, also a reduced-order model is proposed with minor impact on the accuracy of the model. Special attention has been paid to monitor the winding temperature with considering the motor lifetime in DC charging mode, this view has not been addressed in IBCs before. The proposed model is then validated against experimental results and 3D finite element method. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
30. Control of an Ultracapacitor-Based Energy Storage System for Source and Load Support Applications.
- Author
-
P, Naresh and Kumar, V. Seshadri Sravan
- Subjects
- *
ENERGY storage , *PULSE width modulation , *MICROGRIDS , *ALGORITHMS , *SUPERCAPACITORS - Abstract
This paper presents a simple pulse width modulation algorithm for control of an ultracapacitor based energy storage system used for source and load support applications. As opposed to dual loop control philosophy that is widely used for backup applications, this paper presents a simple single loop current control that is only useful for controlling the ultracapacitor based DC/DC converters used in source and load support applications. The proposed PWM blocking method necessitates the DC/DC converter to operate in five states and takes into consideration the essential operational limits associated with the ultracapacitors. The performance of the proposed algorithm is verified experimentally using a 24 V laboratory prototype setup. Further, the shortcomings of dual loop control when applied to source and load support applications are demonstrated. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
31. Investigation of Asymmetric and Unbalanced Winding Structures for 3-Phase Permanent Magnet Synchronous Machines.
- Author
-
Demir, Yucel, EL-Refaie, Ayman M., and Aydin, Metin
- Subjects
- *
PERMANENT magnets , *PERMANENT magnet motors , *SLOT machines , *ELECTROMAGNETS , *FINITE element method , *MACHINERY - Abstract
In this study, an investigation of winding structures is performed for 3-phase unbalanced and asymmetric winding permanent magnet (PM) machines including different slot-pole combinations. There are two different cases for unbalanced winding (UBW) structure: 1) Stator slot number of the machine is divisible by three, 2) Stator slot number of the machine is not divisible by three. Only the first case is examined in this paper. The unbalanced winding layouts are created for minimum unbalance and maximum winding factor. Total magneto motive force (MMF) distributions for nine different slot-pole combinations and their harmonic contents are presented. Variation of the amount of unbalance for different slot-pole combinations is also provided in the paper. Key issues arising from the asymmetric and unbalanced windings such as degree of asymmetric and unbalanced magnetic pull are explored. A prototype motor with 39-slots and 12-poles has been manufactured for experimental verification. A comparison between the finite element analysis (FEA) results and experimental results is presented for the prototype motor for both no-load and on-load conditions. It is shown that the asymmetric and unbalanced winding PM motors have significant potential for applications requiring smooth torque operation. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
32. Vibration Reduction of SRM Through Controlling the Average of Applied Demagnetization Voltage.
- Author
-
Malekipour, Amirhosein, Nejad, Sayed Morteza Saghaian, and Rashidi, Amir
- Subjects
- *
DEMAGNETIZATION , *VOLTAGE , *SWITCHED reluctance motors , *RELUCTANCE motors - Abstract
Although Switched Reluctnace Motors have many advantages, vibration is known as their most severe drawback acting as an impediment limiting their widespread use in industrial and domestic applications. Through electromechanical relationships, it is shown that the first-order time derivative of applied phase voltage and second-order time derivative of radial force directly affect the amplitude of generated vibration, especially at the beginning of demagnetization instance. Therefore, a set of criteria is stated in this paper meeting which ensures having low vibration intensity. In this paper, three types of demagnetization voltages are proposed which comprehensively meet the stated criteria. These voltages share the same characteristics contributing to the vibration reduction in Switched Reluctance Motor. Two vital parameters of Synchronous Counter and Coefficient are included in the proposed demagnetization voltages which must be meticulously chosen in order to be effective. Noticeable contribution of the proposed methods to the vibration alleviation is validated through simulation and experimental tests conducted under different working conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
33. A Decentralized Automatic Load Power Allocation Strategy for Hybrid Energy Storage System.
- Author
-
Wang, Zhishuang, Wang, Ping, Jiang, Wentao, and Wang, Peng
- Subjects
- *
MICROGRIDS , *ENERGY storage , *HARDWARE-in-the-loop simulation , *HYBRID power systems , *SERVICE life , *IMPEDANCE control - Abstract
A decentralized improved I-V droop control strategy for battery-supercapacitor (SC) hybrid energy storage system (HESS) is proposed in this paper. The dynamic power sharing between battery and SC is realized by replacing the constant droop coefficient in I-V droop control with virtual impedance, i.e. virtual inductance for battery side converter and virtual resistance for SC side converter. Besides, by injecting the virtual inductance in the battery side converter, negligible DC bus voltage deviation can be achieved without extra voltage compensator. Moreover, the state-of-charge (SoC) recovery is also considered to extend the service life of the HESS. Furthermore, in the proposed regulated power system, since the power allocation, DC bus stability and SoC recovery are decoupled from each other, the design of control parameters is simple. The corresponding design guideline is demonstrated in this paper. Finally, to verify the accuracy and feasibility of the theoretical analyses, hardware in the loop simulations have been conducted. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
34. Improved Model Predictive Current Control of the Versatile Buck-Boost Converter for a Photovoltaic Application.
- Author
-
Restrepo, Carlos, Barrueto, Brian, Murillo-Yarce, Duberney, Munoz, Javier, Vidal-Idiarte, Enric, and Giral, Roberto
- Subjects
- *
DC-to-DC converters , *MAXIMUM power point trackers , *ANALOG-to-digital converters , *PREDICTION models , *COST functions - Abstract
The digital implementation of all the control loops of a versatile buck-boost (VBB) dc–dc converter used in a stand-alone photovoltaic application is proposed in this paper to improve existing digital-analog sliding-mode-based implementations. All three control loops: maximum power point tracking (MPPT), fast input voltage regulation, and inner high-bandwidth current control, have been programmed in the same digital signal controller (DSC). A Model Predictive Control (MPC) based algorithm has satisfactorily solved the challenge of implementing the nominal 100 kHz switching frequency current loop. The MPC cost function is distributed throughout the algorithm to achieve three specific goals: the tracking of the reference current (G1), a quasi-constant steady-state switching frequency (G2), and the assurance that the duration of an interval is larger than the time required to calculate it (G3). The third goal requires the current control to toggle between peak- and valley-modes depending on the operating point. The correct fulfillment of these control objectives on the proposed MPC-based algorithm has been validated through simulations and experimental tests performed on a purpose built-prototype. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. Model Reference Adaptive System Based Apparent Power Sharing in Inverter Based Microgrids.
- Author
-
Aquib, Mohd., Vijay, A. S., Doolla, Suryanarayana, and Chandorkar, Mukul C.
- Subjects
- *
MICROGRIDS , *SHARING , *INFORMATION networks , *REACTIVE power - Abstract
Power sharing amongst sources can be improved in an islanded microgrid by utilizing the information of the network’s impedance. In this paper, an impedance based model reference adaptive system (Z-MRAS) scheme is proposed to estimate the impedance angle for converter based distributed generators (DGs) in the islanded mode. The focus is to enhance the proportional apparent power sharing between the DGs operated using generalized droop control (GDC). The performance of GDC depends on the effective tie-line impedance between the DGs and the proposed MRAS scheme provides the feedback of the estimated impedance angle. The accuracy of the impedance angle estimation is established for various tie-line $X/R$ ratios, and this results in enhanced power sharing performance for balanced, harmonic, unbalanced, dynamic and constant power load cases as well as parallel line and underground cable cases. The proposed method is validated through off-line simulations in MATLAB and controller hardware in loop (CHIL) using real time simulator (Opal-RT) including cases of meshed networks and DG plug and play for a modified CIGRE network. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
36. A Current Harmonic Suppression Method for PMSM Based on Harmonic Prediction Adaptive Notch Filter.
- Author
-
Zhang, Qiushi, Fan, Ying, Chen, Junlei, Yang, Can, and Cheng, Ming
- Subjects
- *
NOTCH filters , *ADAPTIVE filters , *ELECTRIC power filters , *FORECASTING , *HARMONIC suppression filters , *STABILITY criterion - Abstract
The adaptive filters (ANF) have been commonly used in current harmonic suppression. However, the digital delay will narrow the stability region and its harmonic suppression performance will be deteriorated at high-speed region. To overcome this problem, this paper proposed two modified ANF. Combining with the deadbeat current (DBC) controller, the effect of digital delay on ANF is analyzed. A simple one step harmonic prediction method (OSPANF) is proposed to replace the traditional steepest gradient method (SGM). Based on the OSPANF, the current can be controlled stably in the high-speed area and the harmonic suppression effect is better than the traditional notch filter. Through bode diagram analysis, OSPANF will have a harmonic amplification peak near the set notch frequency, which may bring additional disturbances. Thus, a two steps prediction adaptive notch filter (TSPANF) is implemented. Through the Experimental results, it can be proved that the proposed TSPANF method has better harmonic suppression effect in the high-speed area than OSPANF and the stability region of the proposed two methods is larger than the traditional method. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
37. Fault Tolerant Variable Structure Control of Six-Phase Induction Generator for Wind Turbines.
- Author
-
Bouyahia, Omar, Betin, Franck, and Yazidi, Amine
- Subjects
- *
WIND turbines , *TURBINE generators , *INDUCTION generators , *FAULT-tolerant control systems , *FAULT-tolerant computing , *STATORS , *WIND power - Abstract
In this paper, a fault-tolerant control of a symmetrical six-phase induction generator based on a variable structure strategy is experimentally tested and compared with a classical proportional-integral controller. For this, we use a linear feedback sliding mode controller with switched feedback gains in such a way to control the inner current loops of this machine. One main drawback of the classical three-phase induction generator is that it is no longer possible to generate electrical power if only one phase is lost on the stator side. To overcome this issue, we will use a squirrel cage six-phase induction machine that can still operate when at least three phases remain on the stator side. This article proposes to use a variable structure control in order to cope with unbalanced currents and also maintain the generation of power when a loss of the stator's phases occurs. The proposed controller shows its robustness and good regulation performance in healthy and faulty modes. The simulation and experimental tests were carried out with a 24 kW induction machine that represents 1/100 of the electrical power of a real wind turbine. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
38. Investigation of Signal Injection Methods for Fault Detection of PMSM Drives.
- Author
-
Xu, Zheng, Zhang, Jianzhong, and Cheng, Ming
- Subjects
- *
HIGH voltages , *VOLTAGE , *ELECTRIC potential measurement , *HARMONIC analysis (Mathematics) - Abstract
Inter-turn short-circuit fault (ISF) is a typical incipient fault of the PMSM, which could be detected by high frequency (HF) signal injection method with high resolution. However, the performance comparisons and key parameter selections for various signal injection methods remain untouched. In this paper, different HF injection signals, including rotating high frequency voltage (RHFV), pulsating high frequency voltage (PHFV) and rotating high frequency current (RHFC), are put forward and compared by extracting the HF fault features in zero-sequence voltage space. Since the RHFV injection method has the advantages of high resolution and simple control structure, the fault features under the RHFV signal injection with different parameters are studied. In order to obtain ISF detection resolution as high as possible, the frequency of the RHFV signal is suggested to be near half the PWM frequency of the PMSM inverter. Simulations and experiments are carried out and the results verify the effectiveness of the theoretical analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
39. Extension of the Generic Multi-Frequency Modelling Method for Type 3 Wind Turbines.
- Author
-
Nouri, Behnam, Kocewiak, Lukasz, Shah, Shahil, Koralewicz, Przemyslaw, Gevorgian, Vahan, and Sorensen, Poul
- Subjects
- *
WIND power plants , *OFFSHORE wind power plants , *PHASE-locked loops , *INTELLECTUAL property - Abstract
Reflecting potential non-linearities of converter-based systems, especially frequency and sequence couplings, is an ongoing challenge for linearized multi-frequency models. Besides, design details are required to develop such models, which either are the intellectual property of manufacturers or require experimental tests. The generic multi-frequency modelling method has been proposed to fill this gap; however, it is only developed for converter-connected systems, e.g., Type 4 Wind Turbines (WT). This paper proposes to extend the application of the generic multi-frequency modelling method for Type 3 WTs. In this way, a theory for patterns of the couplings in Type 3 WTs is proposed. Accordingly, a group of emissions and couplings are Rotor-Speed-Dependent (RSD). The RSD emissions and couplings are particular characteristics of Type 3 WTs, which should be addressed in the generic multi-frequency models. The proposed theory is verified by unique-worldwide experimental perturbation tests on a 2 MVA Type 3 WT using a 7 MVA grid emulator. Accordingly, a limited number of RSD couplings and emissions are observed in the test results, mainly in low frequencies (below 1 kHz). Therefore, addressing the RSD couplings is practical and important to extend the generic multi-frequency modelling for Type 3 WTs. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
40. Online Fault Diagnosis Method for Grid-Connected Inverters Based on Finite-Set Mixed Logical Dynamical Model Prediction.
- Author
-
Lin, Qiongbin, Yu, Kai, Zeng, Xinglan, Zong, Yi, Su, Xianjin, Cai, Fenghuang, and Zhan, Yin
- Subjects
- *
DIAGNOSIS methods , *ELECTRIC inverters , *ENERGY storage , *PREDICTION models , *ELECTRIC fault location , *FAULT location (Engineering) , *ELECTRICAL energy , *FAULT diagnosis - Abstract
The grid-connected inverter is a key device in the renewable energy power generation system and large-scale energy storage system, which the operational stability and reliability are the basis for the efficient and safe application of electrical energy. A real-time fault diagnosis method of a three-phase for grid-connected application combining a mixed logic dynamic (MLD) model and finitecontrol set model predictive control (FCS-MPC) is proposed. This paper not only realizes the open circuit fault diagnosis and location of the switching devices in the main power circuit, but also discusses the threshold issues and post-fault operations. The advantage of the proposed method is that it directly uses the control data and measurement signals of the controller without extra sensors and calculation, which will shorter the fault diagnosis time and occupy less calculation resource of the main processor. Simulation results illustrate the quickness of the fault identification and accurate position with robustness to the interference of the diagnosis method. Finally, the effectiveness of the diagnosis method was verified by a 1500 W experimental prototype in a laboratory. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
41. Vibration Characteristics of Permanent Magnet Motor Stator System Based on Vibro-Inertance Matrix Method.
- Author
-
Li, Quanfeng, Liu, Shichang, and Hu, Yihua
- Subjects
- *
PERMANENT magnet motors , *STATORS , *FINITE element method , *TRACTION motors - Abstract
The vibration characteristics of stator system of the interior permanent magnet synchronous motor for EV are deeply studied in this paper, the effectiveness of reducing the vibration by optimizing the vibro-inertance (acceleration admittance) of the stator system is validated. Firstly, the theory of the vibro-inertance matrix of stator system with single-point excitation and multi-point response is proposed, and the mathematical theory model of vibro-inertance matrix of prototype motor stator system is established. Secondly, a new method of 3D finite element method (FEM) be used to simulate and analysis the vibro-inertance's characteristics for the prototype's stator system. Then, the correctness of the theory and the FEM simulation is verified by the prototype source-path-contribution (SPC) experiment. And it is found that near some non-natural frequencies with large vibro-inertance amplitudes, although the amplitude of operating force is relatively small at these frequencies, the prototype still produces large vibrations. Finally, three methods for optimizing the vibro-inertance matrix of the stator system are further studied. These methods can effectively shift the inertance frequency band of the stator system and change the average value of the inertance's amplitude of the motor stator system in different frequency bands, thereby changing the vibration characteristics of the whole motor. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. Estimation of Two- and Three-Dimensional Spatial Magnet Temperature Distributions for Interior PMSMs Based on Hybrid Analytical and Lumped-Parameter Thermal Model.
- Author
-
Liang, Dawei, Zhu, Z. Q., Shao, Bo, Feng, Jianghua, Guo, Shuying, Li, Yifeng, and Zhao, Anfeng
- Subjects
- *
TEMPERATURE distribution , *MAGNETS , *EDDY current losses , *PERMANENT magnets , *FINITE element method , *HEAT conduction - Abstract
A hybrid analytical and lumped-parameter thermal model is proposed in this paper to estimate the transient and steady-state two- and three-dimensional (2/3-D) spatial magnet temperature distributions for an interior permanent magnet synchronous machine (IPMSM). On the basis of a lumped-parameter thermal model (LPTM), the magnet analytical thermal models (ATMs) are synergized to establish the hybrid thermal model. By utilizing the transient or steady-state boundary conditions calculated by the LPTM, the ATMs are obtained by solving the heat conduction equations to estimate the spatial magnet temperature distributions in the 2-D horizontal-vertical and axial-vertical planes, which can also be extended to the 3-D temperature distribution by utilizing the multi-slice method. Meanwhile, the non-uniform magnet eddy current loss is also considered. Finally, both electromagnetic-thermal coupled finite element analysis method and experiments are used for verification based on a totally enclosed IPMSM. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
43. Investigation of Stator/Rotor Pole Number Combinations and PM Numbers in Consequent-Pole Hybrid Excited Flux Reversal Machine.
- Author
-
Wei, Fangrui, Zhu, Z.Q., Yan, Luocheng, and Qi, Ji
- Subjects
- *
STATORS , *PERMANENT magnets , *FINITE element method , *MAGNETISM , *ROTORS , *GLOBAL optimization , *IRON - Abstract
This paper investigates the influence of stator/rotor pole number combinations and permanent magnet (PM) numbers on electromagnetic performance of consequent-pole hybrid excited flux reversal machines (CP-HEFRMs), which have different numbers of PM poles and iron poles and concentrated AC and DC windings on the stator and a salient pole rotor. PMs in the slots of one stator pole are magnetized radially in the same direction, while opposite on adjacent stator poles. Magnetic field paths of DC, PM, and hybrid excitations are investigated. The phenomenon of flux cancellation, i.e., PM and DC MMFs in CP-HEFRMs are of opposite polarities in the flux-enhancing operating mode, is revealed and verified, for the first time, as the key feature that makes CP-HEFRMs different from other hybrid excited machines. Consequently, the saturation in stator pole and yoke can be mitigated and hence the overload capability of DC excitation is enhanced, which is verified by finite element analysis (FEA). Global optimizations are utilized to obtain the optimal rotor and stator pole number combinations and PM numbers for each stator pole. Torque, torque ripple, inductance, unbalanced magnetic force, and flux regulation capability are compared for different PM numbers and rotor pole numbers. Comparisons are made on consequent-pole and non-consequent-pole topologies in terms of torque capacity, flux regulation capability, and PM consumption to further illustrate the advantages of consequent-pole topology. A prototype machine is built and tested to validate the analyses. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
44. Data-Driven Fault Diagnosis for PEM Fuel Cell System Using Sensor Pre-Selection Method and Artificial Neural Network Model.
- Author
-
Xing, Yanqiu, Wang, Bowen, Gong, Zhichao, Hou, Zhongjun, Xi, Fuqiang, Mou, Guodong, Du, Qing, Gao, Fei, and Jiao, Kui
- Subjects
- *
ARTIFICIAL neural networks , *PROTON exchange membrane fuel cells , *FAULT diagnosis , *FAULT-tolerant control systems , *FUEL systems - Abstract
Fault diagnosis is a critical process for the reliability and durability of proton exchange membrane fuel cells (PEMFCs). Due to the complexity of internal transport processes inside the PEMFCs, developing an accurate model considering various failure mechanisms is extremely difficult. In this paper, a novel data-driven approach based on sensor pre-selection and artificial neural network (ANN) are proposed. Firstly, the features of sensor data in time-domain and frequency-domain are extracted for sensitivity analysis. The sensors with poor response to the changes of system states are filtered out. Then experimental data monitored by the remaining sensors are utilized to establish the fault diagnosis model by using the ANN model. Levenberg-Marquardt (LM) algorithm, resilient propagation (RP) algorithm, and scaled conjugate gradient (SCG) algorithm are utilized in the neural network training, respectively. The diagnostic results demonstrate that the diagnostic accuracy rate reaches 99.2% and the recall rate reaches 98.3% by the proposed methods. The effectiveness of the proposed method is verified by comparing the diagnostic results in this work and that by support vector machine (SVM) and logistic regression (LR). Besides, the high computational efficiency of the proposed method supports the possibility of online diagnosis. Meanwhile, detecting the faults in the early stage can provide effective guidance for fault tolerant control of the PEMFCs system. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
45. Pole and Segment Combination in Concentric Magnetic Gears: Vibrations and Acoustic Signature.
- Author
-
Nielsen, Simon Staal, Wong, Ho Yin, Baninajar, Hossein, Bird, Jonathan Z., and Rasmussen, Peter Omand
- Subjects
- *
ACOUSTIC vibrations , *GEARING machinery vibration , *EIGENFREQUENCIES , *MAGNETISM , *NOISE , *TORQUE , *ODD numbers - Abstract
This paper studies the influence of cogging torque and unbalanced radial magnetic forces on vibrations and acoustic noise properties in concentric magnetic gears. The study involves three physical demonstrators, each with unique properties that make them interesting study cases. The first magnetic gear have pronounced cogging torque due to the pole and segment combination. In the second magnetic gear very low cogging torque is obtained by choosing an odd number of segments, but at the expense of unbalanced radial magnetic forces. The fact that these two magnetic gears are designed to identical specifications and into the same system makes this study unique, as this yields a direct and very clear comparison of the influence of cogging torque and unbalance radial forces. The third gear is designed with a pole and segment combination that has a good balance between minimizing cogging torque and avoiding unbalanced radial forces. Acoustic and vibrational signatures are presented and the characteristics are discussed in each case. It is shown that both cogging torque and unbalanced radial forces in concentric magnetic gears dominate both acoustic and vibrational properties and it is shown how it makes the magnetic gears very sensitive to the eigenfrequencies of the system. Even though cogging torque and unbalanced radial forces are dominant, it is also shown how other excitation mechanisms such as eccentricity, segment passing frequency and pole passing frequency are clearly visible in the acoustic and vibrational signatures. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
46. Heterodyne Controlled Matrix Converter as a Direct Frequency Reduction Method for Microturbine Generators (MTG).
- Author
-
Tayar, Tal, Navon, Aviad, Shmilovitz, Doron, and Levron, Yoash
- Subjects
- *
MATRIX converters , *FREQUENCY changers , *VOLTAGE , *VOLTAGE control - Abstract
In this paper a control method for a matrix converter (MC) based on the heterodyne concept from the communication field is presented. The method is used to convert the high frequency of a microturbine generator’s (MTG) output voltage to the utility grid’s frequency. In this control method a frequency modulation (FM) of the MC’s switching frequency is achieved using a DQ0 analysis of the converter’s filtered output voltage with the utility grid’s frequency as a reference. After filtration, the MC achieves a conversion to the reference frequency with a minimal total harmonic distortion (THD) of the output voltage while using a low switching frequency. In addition, the proposed method decouples the output frequency, phase angle and voltage amplitude, which allows them to be controlled separately. This significantly simplifies the required control, and enables a robust and low-cost design. The theoretical analysis, simulation and experimental results of the method are reported. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
47. A Generalized, Fast and Robust Open-Circuit Fault Diagnosis Technique for Star-Connected Symmetrical Multiphase Drives.
- Author
-
Sun, Jiawei, Li, Chi, Zheng, Zedong, Wang, Kui, and Li, Yongdong
- Subjects
- *
FAULT diagnosis , *FAULT-tolerant control systems , *FAULT location (Engineering) , *VARIABLE speed drives , *ELECTRIC fault location , *SIGNAL detection , *MACHINE performance - Abstract
Multiphase drives with fault-tolerant capability are favored in high-reliability applications. In most fault-tolerant multiphase drives, the fault types and locations must be known prior to the fault-tolerant control. Therefore, fault diagnosis is an indispensable procedure. This paper proposes a generalized method to detect and identify the open-circuit faults (including open-switch and open-phase faults) in star-connected symmetrical multiphase drives with different phase numbers. The selected fault diagnosis signals are calculated solely from simple arithmetical operations of measured phase currents, resulting in easy real-time implementation. As fault detection signals are derived from the physical constraint imposed by the neutral point, the proposed method is naturally robust and not sensitive to operating points, machine transients and harmonics in stator currents. Therefore, a relatively small fault detection threshold can be used and fast detection can also be achieved. After the fault has been detected, the fault type is further identified according to the polarity of the integration of phase currents. Experimental results on nine-phase and five-phase induction machine drives verify the generality, fast diagnosis speed and robustness of the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
48. Broken Rotor Bar and Rotor Eccentricity Fault Detection in Induction Motors Using a Combination of Discrete Wavelet Transform and Teager–Kaiser Energy Operator.
- Author
-
Agah, Gholam Reza, Rahideh, Akbar, Khodadadzadeh, Hosein, Khoshnazar, Seyed Moslehoddin, and Hedayatikia, Shahin
- Subjects
- *
INDUCTION motors , *SQUIRREL cage motors , *WAVELET transforms , *ROTORS , *TORQUE control , *POWER resources , *DISCRETE wavelet transforms - Abstract
In this paper, a hybrid approach is proposed to detect the broken rotor bar and rotor mixed eccentricity faults of three-phase squirrel cage induction motors based on one phase of the stator current signal. The hybrid method is based on a combination of discrete wavelet transform (DWT), Teager–Kaiser energy operator (TKEO) and power spectral density (PSD). At the first stage, DWT is applied on the stator current signal; then TKEO is applied on some of the DWT detail coefficients and finally PSD is used to extract the required feature to detect the aforementioned faults. The proposed method is tested on an experimental test-rig having a 1.5 kW induction motor under various load conditions and three different power supplies: 1) directly supplied by power grid; 2) supplied by a drive system based on scalar control technique; and 3) supplied by a drive system based on direct torque control (DTC) technique. The results show the efficacy of the proposed method in accurate detection of the broken rotor bar and rotor mixed eccentricity faults. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
49. Nonlinear Analytical Model for Performance Prediction of Eddy Current Recoil Brake.
- Author
-
Li, Jiahao, Yang, Guolai, Sun, Quanzhao, and Wang, Liqun
- Subjects
- *
AIR gap flux , *MAGNETIC flux leakage , *MAGNETIC flux density , *SPECIFIC gravity , *MAGNETIC circuits - Abstract
In this paper, a nonlinear analysis model for predicting the performance of eddy current recoil brakes (ECRB) is proposed by combining the magnetic equivalent circuit (MEC) model and the subdomain model. The subdomain model introduces the equivalent region to improve the inherent shortcomings of the equivalent current sheet (ECS) method. The outer tube is divided into a magnetic saturated region and an unsaturated region in the subdomain model to simulate the magnetic saturation of the outer tube during recoil. The MEC model is applied to calculate the air gap magnetic flux density and the relative permeability of the equivalent region. Leakage flux and magnetic saturation are considered in the MEC model. The eddy current resistance of ECRB is calculated by the subdomain model. The model is verified by the finite element model, and it is able to predict the performance of ECRB with different structural parameters. In addition, the prototype of the ECRB was manufactured. A test was carried out on a 155 mm artillery to verify the accuracy of the proposed nonlinear analysis model. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
50. The Energy Transition’s Impact on the Accumulated Average Efficiency of Large Hydrogenerators.
- Author
-
Karekezi, Yannick Cyiza, Oyvang, Thomas, and Noland, Jonas Kristiansen
- Subjects
- *
HYDROELECTRIC generators , *SYNCHRONOUS generators , *ECONOMIC impact , *SUPPLY chain management , *REACTIVE power , *WATER power - Abstract
The energy transition is aimed to take advantage of the operational flexibility of hydropower to extend the integration of intermittent renewable sources. Consequently, the hydrogenerators will have to operate in regimes far away from their designed best-point operation. In order to accurately assess the impact, this paper presents a useful approach to determine the overall operating efficiency of synchronous generators under intermittent operation. An accumulated average efficiency (AAE) model is proposed and compared against an alternative approach; the weighted average efficiency (WAE) model. It is found that the WAE approach produces unrealistic low efficiencies when the generator operates in synchronous condenser mode (SCM) for long periods. In general, the AAE supersedes the WAE for all the different load distributions that were investigated. This was further illustrated by a worked example and by constructing more complex load distributions. A load distribution dominated by SCM yields a difference as high as $33.18 \,\%$ , while an even distribution deviates $1.43 \,\%$ in their respective efficiencies. Finally, a yearly on-site measurement of our studied $103 \,\mathrm{MVA}$ generator’s concentrated load distribution revealed a discrepancy of $0.67 \,\%$ , which is a significant deviation considering what the operating regime would mean in terms of economic implications. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.