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This paper aims to introduce a new multilevel inverter topology less number of switches and gate drivers with a hybrid control method. In the proposed topology three kinds of voltage sources are utilized in the topology. A combination of these voltage sources, switches, and two H-bridges derived a new topology. Moreover, combining the nearest level and pulse width modulation created an efficient way to control the proposed topology which is described in this paper. Equations to determine the number of components and total standing voltage of the proposed multilevel is presented. A comprehensive comparison between the proposed topology and other best topologies is made. Additionally, the simulation results which are obtained by PSCAD/EMTDC and experimental results are in accordance with the theory. The proposed multilevel inverter with a hybrid control method has less number of switches, gate drivers, and low THD. [ABSTRACT FROM AUTHOR]

This paper studies the THD and AC losses on the DC cables of offshore wind farm-based multi-terminal HVDC systems when they extract and deliver power from and to more than one connection point. In the paper, the study of a full system PLECS + Simulink model with two branches, including a wind resource, a wind turbine, a Permanent Magnet Synchronous Generator (PMSG), a Pulse Width Modulation (PWM) rectifier, a Single Active Bridge (SAB) DC–DC converter, an Input Parallel Output Series (IPOS) DC–DC converter, HVDC cables, and a simplified onshore system, is presented. It focuses on the investigation of the output ripple content of multiple DC–DC converters on DC cables under different wind conditions with different voltage and power ratings. The importance of the study is providing a general understanding of the operation of the innovative offshore wind farm-based DC system, as well as the interaction between different DC–DC converters and their influence on cable ripple content under different situations. [ABSTRACT FROM AUTHOR]

The phase circulating current (PCC) of the parallel three-phase inverter systems dramatically affects the power quality and conversion efficiency of the power grid. In this paper, a composite suppression strategy is proposed to solve the PCC issue by using the sliding mode control (SMC) approach and improved virtual impedance droop control. Taking the commonly used 2-group parallel three-phase inverter as an example, an inter- and intra-classification model is established by analyzing the sources of PCC. In order to suppress the inter-PCC, the traditional virtual impedance droop control is given, following the improved substitute by combining SMC. And the variables of the bus voltage, Q-U loop, P-f loop, and the virtual-induced reactance are also introduced for the robust control of the impedance droop. On the other side, a SMC-based suppression approach is designed to solve the issue of the intra-PCC. Its idea is to introduce a regulation factor for the space vector pulse width modulation (SVPWM) so that the zero-sequence voltage can be eliminated and the influence of the intra-PCC can be relieved. Comparative simulations and experiments validate the effectiveness of the methods proposed in this paper. [ABSTRACT FROM AUTHOR]

Nowadays, transformer-less photovoltaic (PV) multi-level inverters (MLIs) are commonly employed in both industrial and residential settings. This structure has attracted increased attention due to its unique advantages, such as higher efficiency, lower cost and size, better waveform quality, and inherent fault tolerance. However, due to the removal of the transformer, the common mode voltage (CMV) becomes one of the crucial issues in transformer-less PV MLIs. The high-frequency variation in CMV results in a leakage current that deteriorates the line current quality, increases the PV power system losses, leads to severe electromagnetic emissions (EMI), reduces the PV array lifespan, and causes personal safety problems. In this regard, this paper presents a review of the existing and recent research on modulation techniques based on space vector pulse width modulation (SVPWMs) that overcome this issue in transformer-less three-level NPC-MLIs (3L-NPC-MLIs). The reduced CMV-SVPWM (RCMV-SVPWM) can be mainly categorized as an RCMV-SVPWM based on the vector type, based on virtual vectors, and based on the two-level SVPWM (2L-SVPWM). Their features and their limitations in terms of several main criteria are discussed. In the final section of this paper, some challenges and future trends for this research area are projected. [ABSTRACT FROM AUTHOR]

To improve the pulse width modulation (PWM) harmonic suppression effect of the three‐phase VSI‐fed PMSM system, this paper proposed a novel random switching period (RSP)‐Space Vector Pulse Width Modulation (SVPWM) technique for the three‐phase power converter. First, the proposed technique replaces the 10‐bit linear feedback shift register pseudorandom number generator (LFSR‐PRNG) with a Tiny Mersenne Twister (MT)‐PRNG to quickly generate high‐quality pseudorandom number sequences. Then, to reduce the sampling error caused by the current ripple, this paper analyzes the sampling timing under different modulation techniques. Based on the interrupted update mechanism of the Infineon AURIX‐TC264, the variable frequency sampling of the RSP‐SVPWM technique is implemented to ensure the best sampling of the motor phase current. Finally, the simulation and experimental results show that the proposed technique can effectively disperse PWM harmonic energy. Meanwhile, the RSP‐SVPWM technique based on variable sampling frequency effectively improves the phase current quality of the PMSM system. The proposed technique shows great potential for suppressing PWM harmonics in integrated PMSM systems. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The shift and low-frequency oscillations of neutral point potential are key issues in the neutral point clamped (NPC) inverter. The space vector pulse width modulation (SVPWM) algorithm has limited voltage balancing ability at high modulation levels and low power factors. The virtual SVPWM can achieve midpoint potential balance across the entire range, but it has the problem of multiple switching times and poor harmonic characteristics. Parallel three-level NPC inverters can increase the power rating and efficiency of systems, thus being suitable for high-power applications. However, their parallel topology also brings current sharing issues. This paper first proposes several methods of combining varied virtual middle vectors based on five-level vectors, which control the midpoint current by adjusting the action time of the basic vector. Second, different virtual vector combinations are used for voltage commands with different modulation indexes to reduce the switching frequency of the inverter and the synthesis vector error. The proposed hybrid method has fewer switching times, reduces the amplitude of midpoint voltage fluctuation, and has good harmonic characteristics of output current. Finally, the feasibility and effectiveness of the hybrid method are verified through simulation and experiments. [ABSTRACT FROM AUTHOR]

The use of three-level converters with low switching frequency (SF) modulation is urgently needed for medium voltage high power applications. However, since it is not possible to frequently adjust the injected zero-sequence voltage and duty time of redundant vectors, the neutral point (NP) voltage problem of three-level converters becomes a tricky issue under low SFs. In this paper, an optimized low SF modulation with NP voltage control is proposed, which is based on half-wave symmetry selective harmonic elimination pulse width modulation. The proposed modulation specifically addresses the low-frequency NP voltage fluctuation of three-level converters, using the amplitude and phase of the 3n-order harmonics as degrees of freedoms (DOFs). In addition, it actively optimizes the control problem into constraint equations. By revealing the relationship between these new DOFs and low-frequency NP voltage fluctuation, and obtaining the optimum settings for the new DOFs, the newly established constraint equations can naturally suppress the low-frequency NP voltage fluctuation, without the need for real-time switching angle adjustments. It fits very well with the feature that switching angles can only be calculated offline and used via a table online. Experimental results show the validity and feasibility of the proposed modulation strategy. [ABSTRACT FROM AUTHOR]

Summary: This paper proposes a step‐down alternating current (AC)/direct current (DC) converter with current‐doubler rectification stage, therefore suitable for low‐voltage and high‐power applications. High power factor and low harmonic distortion can be achieved by simply applying sinusoidal pulse‐width modulation (SPWM) control. A laboratory prototype circuit rated at 2 kW, 180‐V output voltage is designed and built to verify the circuit feasibility. Experimental results confirm that the power factor is ubiquitously higher than 0.99 from 500 W to the full load. The total harmonic distortion at the full load is less than 5%, which meet the harmonic specifications of IEC 61000‐3‐2 and IEC 61000‐3‐12. [ABSTRACT FROM AUTHOR]

Cascaded H-bridge inverters, which belong to strongly nonlinear time-varying system with complex dynamics, have been widely used in high-voltage and high-power engineering fields. In this paper, a carrier phase-shifted sinusoidal pulse-width modulation cascaded H-bridge inverter is taken as an example with piecewise analysis to establish the discrete iterative mathematical model. Furthermore, the nonlinear dynamic behavior of this inverter system is investigated using folding diagrams, spectrum diagrams, bifurcation diagrams, Lyapunov exponents, etc. We find that this inverter can exhibit multiperiod bifurcation, tangential bifurcation and paroxysmal chaos within certain ranges of control coefficients and other circuit parameters, which will influence the system's stability seriously. On the basis of this discovery, the sinusoidal time-delay feedback control method is proposed. The difference between the load current of the controlled object and its own delay is used to form a feedback term, which is then fed into the sine function and proportional link to obtain the control term. Moreover, the Jacobian matrix of this feedback inverter system is derived, and the constraints on the feedback control coefficient are obtained based on the Jury criterion. Simulation results have verified the effectiveness of such a sinusoidal time-delay feedback control method, which can improve the stability and anti-interference of the system. The research can be used to provide some reference and guidance for the circuit design, debugging and control of cascaded H-bridge inverters. [ABSTRACT FROM AUTHOR]

In this paper, a new active snubber cell for DC‐DC boost converters is introduced for the purpose of soft switching. The introduced snubber cell ensures lossless turning‐on by zero‐voltage transition (ZVT) and turning‐off by zero‐voltage switching (ZVS) of the main switch. Besides, it enables turning‐on by ZVS and turning‐off by zero current switching (ZCS) of the main diode. None of the semiconductor power devices are subjected to extra voltage stress, and all of them operate by soft switching (SS). The converter can successfully maintain the SS even under light loads. Furthermore, the proposed converter structure is advantageous in terms of simplicity and low cost. The operating modes and theoretical analysis of the introduced converter are presented and it is validated using a prototype with a 500 W output power and at the 100 kHz switching frequency. Owing to the proposed active snubber cell, the converter efficiency is achieved as 97.2%. [ABSTRACT FROM AUTHOR]

The traction converter modulation generates switching-frequencies current harmonics. The trapped filters can eliminate these switching harmonics, reducing total inductance and filter size. Nonetheless, in comparison with the typical inductor-capacitor-inductor (LCL) filter, the trap inductor needs a larger magnetic core. Moreover, the trapped filter has not been analyzed in the traction systems. This paper proposes a magnetic integrated inductor-trap-inductor (LLCL) filter to decrease the filter's size and investigate its application in traction converters. In fact, the application range of this filter is quite broad, and it can be used in various electrical power systems, including industrial power systems, renewable energy systems, transportation systems, and building power systems. The LC-trap may be formed by connecting the equivalent trap inductor, introduced through the magnetic coupling between inverter-side and grid-side inductors, in series with the filter capacitor. Furthermore, for H-bridge unipolar pulse width modulation (PWM) traction converters, the prominent switching harmonics are concentrated at the double switching frequencies. Therefore, the stability zone is expanded by moving the resonance above the Nyquist frequency. The presented filter's features and design are thoroughly analyzed. The proposed method is finally validated by the MATLAB/Simulink simulation and hardware-in-the-loop (HIL) experimental results. Compared to the discrete windings, the integrated ones can save two magnetic cores. Furthermore, the proposed filter can meet IEEE criteria with 0.3% for all the harmonics and total harmonic distortion (THD) of 2.15% of the grid‐side current. [ABSTRACT FROM AUTHOR]

Summary: In a unidirectional five‐level ac motor drive system with open‐end winding connection, because of the variation of operating frequency of ac motor, the instantaneous power fluctuation of rectifier stage and inverter stage will generate larger voltage ripple on each phase dc‐link capacitors, and further lead to a large amount of current harmonics in output currents of inverter. To cope with this problem, an improved space vector pulse width modulation (SVPWM) strategy based on dc‐link voltage feedforward is proposed. In this paper, the effects of zero sequence current harmonics caused by dc‐link voltage ripple on ac motor are firstly analyzed, including the stator winding flux linkage equation, voltage equation, and electromagnetic torque. Then, the generating mechanism of dc‐link voltage ripple and the current harmonics are discussed in detail in terms of instantaneous power fluctuation of each single‐phase converter. Based on this, an improved SVPWM strategy by modifying the modulation signal is proposed to suppress the generation of current harmonics. Finally, a 2.2 kW prototype experimental results are given, which verify the feasibility and advancement of the proposed modulation strategy. [ABSTRACT FROM AUTHOR]

An improved combined-mode power converter (CMPC) for a solar photovoltaic (SPV) system is presented in this paper. Ten-power electronic switches are utilised for the functioning of the converter. The proposed converter has four modes of operation: buck, boost, inverter, and mixed mode. The new CMPC topology provides a unique and complex switching sequence for implementing the mixed-mode operation. This work uses a field-programmable gate array (FPGA) for mode selection and to create PWM (MS-PWM) signals. A digital MS-PWM controller is configured to switch between improved stepped perturb and observe (ISPO) maximum-power point tracking (MPPT) and sine wave PWM (SPWM). The ISPO provides the appropriate duty cycle for buck/boost operation, while the SPWM controls the inverter operation. This work's new digital PWM control algorithm supports mode selection, PWM generation, and reconfiguring PWM generation timings. The whole framework for constructing the MS-PWM controller employs a very high-speed integrated circuit hardware description language (VHDL). Simulation and experimental results are presented, proving that the digital MS-PWM controller uses fewer resources with improved accuracy. [ABSTRACT FROM AUTHOR]

The two-stage power converter is currently the most widespread topology for three-phase grid-connected photovoltaic (PV) systems. The PV power is injected to the grid through the regulation of the dc-link voltage. This method is commonly called the voltage control method, whereby the current is controlled indirectly. This paper focuses on the modelling of power converters and the parameter design of proportional-integral (PI) controllers, based on the bandwidth of the inner current loop and the outer voltage loop. It is assumed that the inner loop has a bandwidth that is ten-fold bigger than that of the outer loop, in order to fully decouple the dual loops. The PI parameters are thus determined through this relationship, and two sets of simulations are run to validate the methodology used. Results show that the controllers give highly satisfactory performance even in the presence of transients introduced by rapidly varying irradiance model. [ABSTRACT FROM AUTHOR]

In PMSM drive systems, sensor-less vector control of permanent magnet synchronous motors (PMSM) over the entire speed range poses considerable challenges. Through the design and simulation of the sensor-less vector control system of PMSM, this paper proposes a novel method for sensor-less field-oriented control (FOC) for PMSM applications. To solve this intricate control problem, FOC combines gh-reference frame space vector pulse width modulation (SVPWM) with cubature Kalman filter (CKF). Implementing CKF to estimate rotor position and speed accurately provides the basis for this sensor-less control technique. Furthermore, the integrated control system using gh-SVPWM aims to reduce controller board computing resources utilization while minimizing torque ripple and stator current harmonic distortion. The effectiveness of CKF-based sensor-less FOC integrated with gh-SVPWM is verified in various operating environments using an extensive simulation and experimental framework, confirming its potential to enhance PMSM driving performance and efficiency in different applications. [ABSTRACT FROM AUTHOR]

This paper presents a novel jitter reduction technique for a voltage-controlled ring oscillator (VCRO). This technique is helpful in employing VCRO-based circuits like Analog to Digital Converter (ADC), Phase Locked Loop (PLL) and time-based circuits whose performance is severely degraded by high jitter. In the proposed technique, the jitter is extracted using Excess Phase Discrimination (EPD) block and is transformed into Pulse Width Modulated (PWM) signal, which is then fed into the Phase Compensator (PC) block. This block reduces the jitter by about half its value after enabling the Single Ended Injection Locking (SEIL). The proposed work is designed in SCL 180 nm CMOS technology at 1.8 V supply. On enabling the proposed circuit, the Root Mean Square (RMS) jitter reduces from 5.94 to 2.58 ps (about 56%) for VCRO running at 58 MHz and consumes a total power of 375.84 μ W. The overall performance of the proposed circuit does not vary much in the post-layout simulations, hence demonstrating the effectiveness of the proposed technique. [ABSTRACT FROM AUTHOR]

Nonlinear loads, crucial components of power system grids, pose a challenge due to harmonics injection. This work tackles this issue with a novel modified green plug–switched filter compensation scheme using fuzzy logic controllers. This innovative scheme presented in this paper utilizes dual action pulse width modulation to ensure switching functions from harmonics reduction and capacitive compensation for inrush nonlinear-type AC loads. The scheme's multi-loop regulations and online switching effectively handle dynamic-type slow-acting inrush, motorized- and other rectifier-type nonlinear loads, enhancing the power factor, power quality at source and load buses, and reducing the total harmonics distortion at the key source and sensitive nonlinear load buses. A simulation model in the MATLAB/SIMULINK-2023b software environment demonstrates the efficiency of the proposed FACTS technique. The modulated dual mode switched filter-capacitive compensation scheme controlled by a fuzzy logic controller ensures less harmonics distortion and improved voltage stabilization. The results show that voltage, current, active power, reactive power, power factor regulation, and effective energy utilization are achievable with the designed Flexible AC Transmission System-Modulated Filter Capacitor Compensation–Switched Filter Compensator (FACTS-MFCC-SFC). The switched modulated AC green plug filter significantly improves power quality and enhances power factor in cases of inrush and nonlinear loads. [ABSTRACT FROM AUTHOR]

It is easy to find electromagnetic contactors in modern electromechanical devices owing to their advantages, which encompass a simple structure, ease of use, and low cost. However, these devices also have inherent drawbacks, including heat dissipation, contact erosion, and inefficient power consumption during long-term operation. This has sparked interest in contact soft-landing, which aims to reduce issues like contact bounces, contact welding, and arcing. This paper presents the development of a testing apparatus for investigating the electromagnetic dynamics of contactors or mechanical relays, aimed at developing an open-loop model-based controller for contact soft-landing. Theoretical equations based on physical theorems are derived to describe the behavior of the electromagnetic coil under varying factors. Additionally, a pilot study was conducted using the proposed testing apparatus to explore the relationship between heat dissipation, flowing current, air gap, and the Lorentz force produced by exposing ferromagnetic material to the magnetic field surrounding the electromagnetic coil. The experimental and simulation results showed good fitting, with a normalized root mean squared error ranging from 2.5% to 4.5% for various scenarios. Notably, it was found that the flowing current passing through the electromagnetic coil can be controlled by changing the duty cycle of the pulse width modulation signal driving the conductivity of the MOSFET. However, the results suggest that a modulation frequency greater than 5 kHz is not suitable for driving the electromagnetic coil. [ABSTRACT FROM AUTHOR]

Summary: The application of modular multilevel converters (MMC) in medium voltage static synchronous compensators (STATCOMs) has been investigated in recent years. A huge challenge for MMC‐STATCOM is to compute the gain of the controllers. Therefore, the contribution of this paper is the proposal of a control tuning methodology for MMC‐STATCOM. For this purpose, the control and tuning strategies are presented. Since MMC‐STATCOM can employ different modulation strategies, two distinct modulation strategies are considered: nearest‐level control, with variable switching frequency; and phase‐shifted carrier pulse‐width modulation, with fixed switching frequency. Moreover, the proposal was validated through simulation and an experimental platform. The results indicate that the power response follows the reference, besides supplying the internal losses of the converter. The 10% ripple tolerance of the submodule voltages is respected in steady state for both modulation strategies. Moreover, the 5% total demand distortion (TDD) limit recommended by the Institute of Electrical and Electronics Engineers (IEEE) standard is attended. These results demonstrate the effectiveness of the controls employed. [ABSTRACT FROM AUTHOR]

The conventional topological approach to eliminate the multiple-input DC voltage requirement in multilevel inverter configurations for synthesizing high-output voltage levels is to deploy split capacitor banks at the input terminal. This method stipulates a less expensive, light weight, and reduced size inverter system. However, the excessive demand for several capacitor banks and the complex voltage balancing strategy associated with this conceptual approach poses numerous limitations in their deployment. In view of these drawbacks, this study proposes a self-balanced, single-phase, nine-level switched-capacitor-based inverter topology consisting of a single-input DC voltage, an auxiliary circuit, and an H-bridge circuit unit. A commensurate single carrier-based sinusoidal pulse-width modulation scheme is developed for the proposed power circuit control, enabling the synthesis of a nine-level output voltage waveform whose amplitude is four times the input voltage value. Detailed power circuit operations and switching functions are adequately provided in the proposed topology. A comparison between the proposed inverter and its recent counterparts in terms of component count, cost involvement, and output voltage-boosting ability is duly carried out using Python data visualization. Results reveal that the proposed inverter competes well in these three criteria. For varying R–L load values, the inverter has the capability of high active and reactive power delivery. Its dynamic response for step changes in the modulation index under these power-mode operations is presented in this paper. For high active power-mode operation, efficiencies of 98.27% and 98.92% under light- and heavy-load conditions, respectively, are obtained on a 3-kW-rated inverter prototype. [ABSTRACT FROM AUTHOR]

Due to the interaction of accumulated charges on the surface of a test mass with the surrounding electric and magnetic fields, the performance of inertial sensors is affected, necessitating charge management for the test mass. Discharge technology based on Ultraviolet LEDs is internationally recognized as the optimal solution for charge management. Precision driving of Ultraviolet LEDs is considered a key technology in charge management. This paper presents the driving control system used for Ultraviolet LEDs, achieving precision pulse-width-modulation-type current output with controllable pulse width and amplitude. The system generates the pulse-width-controllable pulse voltage signal via analog pulse-width modulation, and subsequently regulates the amplitude of the PWM signal through range switching. To convert the voltage into the pulse-width-modulation-type driving current, the improved Howland current source is employed. The test results demonstrate that the driving control system can output controllable current in the range of 0.01 mA to 10 mA, with a minimum step of 0.01 mA. The accuracy of the current reaches 1%, the stability within 1 h is better than 1%, and the load regulation is better than 2%. The driving control system provides an important reference for the integration of charge management system and the precision drive control method for LEDs. [ABSTRACT FROM AUTHOR]

The AC battery utilizing second-life time batteries has gained great interest currently with the advantages of both power solutions and economic benefits. In this system, the power converters play a crucial role in the stable and effective operation of the system. This paper focused on the AC/DC stage with the chosen topology being the interleaved full bridge (IFB) converter due to its flexibility and the ability to increase the power rate of the system. For the sake of high-performance operation, various pulse width modulation (PWM) methods for this converter are analyzed. First, based on the theory of the traditional PWM methods for a full bridge inverter in combination with the interleaved technique, this paper proposed three interleaved PWM methods for the IFB converter. Secondly, the proposed methods are theoretically compared in terms of the output current, common-mode voltage, and power losses. Finally, the evaluation is carried out by both the simulation and the experimental prototype, in which the results are in good agreement with the theoretical analysis. [ABSTRACT FROM AUTHOR]

An improved carrier‐based pulse‐width‐modulation (CBPWM) technique for a three‐level (3L) F‐type neutral point‐clamped (FNPC) inverter is presented in this paper. By using the proposed modulation scheme, the DC‐link capacitor voltage at the neutral point is balanced. For manufacturers, reliability is one of the major concerns for all power electronics devices and parts. This paper proposes an extensive reliability analysis of the 3L‐FNPC inverter. Considering the mean time to failure (MTTF) of each device, the reliability of the 3L‐FNPC inverter is analyzed in this present work by using two different methods, which are the approximate method and the exact method. To compute the failure rate of the equipment, only the number of components is considered in the approximate method. Alternatively, exact methods are utilized to evaluate the reliability of a system by knowing the different stress levels and various operating environments of a specific system. Because of the strong correlation between device failure and temperature stress factors, power loss analysis is used in the exact method. The MATLAB Simulink environment is used to determine the power loss of the switching devices. A solar off‐grid photovoltaic (PV) system is considered for reliability testing. Experimental mission profile data are used to estimate the lifetime of the 3L‐FNPC inverter by applying the rainflow counting algorithm, the Coffin‐Manson model, and Miner's rule. The competitiveness, effectiveness, and reliability of the 3L‐FNPC inverter with the proposed modulation technique are validated using a hardware prototype. [ABSTRACT FROM AUTHOR]

To ensure that a variable-rate spray (VRS) system can perform unmanned aerial spray in accordance with a prescription map at different flight speeds, we examine in this paper such significant factors as the response time of the VRS system and the pressure fluctuation of the nozzle during the variable-rate spraying process. The VRS system uses a lag compensation algorithm (LCA) to counteract the droplet deposition position lag caused by the system response delay. In addition, pulse width modulated solenoid valves are used for controlling the flowrates of the nozzles on the variablerate spray system, and a mathematical model was constructed for the spray rate (L min-1) and the relative proportion of time (duty cycle) each solenoid valve is open. The pressure drop and solenoid valve response time at different duty cycles (50~90%) were measured by indoor experiments. Meanwhile, the lag distance (LD), spray accuracy, and droplet deposition characteristics of the VRS system were tested by conducting outdoor experiments at different flight speeds (4m s-1, 5m s-1, 6m s-1). The results show that LCA can effectively reduce the LD. The LD values of the VRS system with LCA ranged from -0.27 to 0.78m with an average value of 0.32m, while without LCA, the LD values increased to 3.5~4.3m with an average value of 3.87m. The overall spray position accuracy was in the range of 91.56~97.32%. Furthermore, the spray coverage and deposition density, determined using water sensitive paper, were used to evaluate the spray application performance taking into account the spray volume applied. The VRS system can provide the most suitable spray volumes for insecticide and fungicide plant protection products. Based on a prescription map, the optimized VRS system can achieve accurate pesticide spraying as well as desirable spray coverage and deposition density. [ABSTRACT FROM AUTHOR]

In this paper, a novel switched capacitor converter has been proposed to generate 7-levels using seven semiconductor switches (7S7L) to get triple gain in the output voltage which is supplied by a single dc source. A PWM technique, phase disposition pulse width modulation (PD-PWM) has been designed to achieve a suitable switching operation for the 7S7L inverter. In addition, the capacitor voltage is balanced and the suggested inverter uses a charging inductor to decrease the capacitor inrush current, which is a shortcoming in the switched-capacitor multilevel inverters. Moreover, the 7S7L inverter is used to interface the solar panels with the utility grid using a synchronous reference frame-based controller. To check the efficiency, taking actual data, power loss calculation has been discussed for the 7S7L inverter. To illustrate the better performance of the proposed 7S7L inverter than the existing seven-level SC-MLI presented in the literature, a comparative study is also undertaken. To verify the feasibility and effectiveness of the proposed topology, a converter is simulated using Matlab/Simulink. To validate the simulation results, a real-time study is completed using the OPAL-RT 4510 real-time platform. [ABSTRACT FROM AUTHOR]

Currently, power trains based on an Open-End Winding Induction Machine fed by a Dual Inverter (DI-OEWIM) are attracting a great deal of interest in various modern industrial applications. However, applying symmetrical control to this system (DI-OEWIM), which is symmetrical in nature, will lead to malfunction. Therefore, the objective of this paper is to explore the influence of asymmetric control on the performance of this system. The principle of this study is to create an asymmetrical control by integrating a phase-shift angle in the Space Vector Pulse Width Modulation (SVPWM) strategy. We then evaluate the impact of these angles on various performances, such as the Total Harmonic Distortion (THD), power losses, Common Mode Voltage (CMV), Zero-Sequence Voltage (ZSV), rotation speed and torque ripple of this system. This study was carried out in the Matlab/Simulink environment and was validated experimentally using the dSPACE 1104 board. The results show that the different angles have significant effects on the overall performance of this system. [ABSTRACT FROM AUTHOR]

High carrier-frequency Pulse Width Modulation (PWM) is a popular and widely used method for driving the induction motors in Electric Vehicles (EVs) using voltage source inverters. However, it often generates high-frequency Common Mode (CM) voltages, resulting in shaft voltages. This, in turn, leads to a flow of leakage current to the earth, known as CM current, which can cause serious problems, including premature failure of the ball bearings in the motor. This paper introduces an Active Cancellation Circuit (ACC) method aimed at extensively reducing the CM current and, consequently, the CM voltage in three-phase induction motor drives. In this technique, Y-configured capacitors are employed for detecting CM voltage. After amplification, this voltage is applied to the motor frame to eliminate both the CM current and the CM voltage. Unlike conventional voltage compensating techniques, the proposed approach eliminates the need for a CM transformer between the inverter and the motor. As a result, there is no need for a high-power-rated CM transformer or any of its associated losses. To assess the effectiveness of the proposed method, experiments were conducted using an induction motor (3-phase, 1.1 kW, 415 V/60 Hz) connected to a two-level three-phase voltage source inverter. [ABSTRACT FROM AUTHOR]

An educational studies and understanding about theoretical and practical laboratory in power quality issues. Interline dynamic voltage restorer is used in the proposed system for mitigating voltage sag, swell, harmonics, and interruptions. The conventional topology of dynamic voltage restorer possessing voltage source inverter is modified into a switched coupled inductor inverter which has the clear edge in power transfer over the former one. The versatility of the controller is enhanced in this work by deploying an artificial neural network combined discrete wavelet transform. The artificial neural network and discrete wavelet transform aided pulse width modulation generation enhances the controller performance by mitigating the harmonics considerably. The simulation and experimental results reveal that interline dynamic voltage restorer renders solution for major power quality issues like voltage sag and swell. Interline dynamic voltage restorer-based SCII is implemented with field programmable gate array Spartan 6 controller and signal processing technique such as discrete wavelet transform that mitigates voltage sag and harmonics. Paper is constructed such that the students in Bachelor's and Master's program of Electrical engineering can understand the power quality, various issues, and mitigating the total harmonic distortion value. The equations related to real power transfer are derived which enable the students to clearly understand about the power exchange between the feeders. Further, it is applied in practical laboratory setup facility for understanding about power quality issues to students of both undergraduate and postgraduate courses. [ABSTRACT FROM AUTHOR]

Electrically powered rail transport is constantly increasing in order to meet the high demand for people and cargo transportation, whether with high-speed trains, subways, suburban trains, or electric tramways. In these types of applications, power electronics solutions such as integrated and efficient converters with multiple functionalities are highly desirable. Among these converters, one family stands out for its ability to generating multiple output terminals with reduced number of switches, namely, the nine-switch converter. Therefore, this paper proposes a multiport converter solution based on the nine-switch converter topology that integrates multiple functionalities with a reduced switch count. The converter, responsible for the power drive of the electric tramway, is exclusively powered by a battery. Moreover, it presents a strategically connected passive filter that provides a low-impedance path for high-frequency currents, avoiding leakage of the current circulation in the induction motor. Its phase-shift pulse-width modulation is capable of reducing the high-frequency components of the current delivered by the battery. The energy storage system is designed to optimize the system capacity based on the known real load profile of a public tramway, with a maximum power of 532.1 kW. The control system is designed and applied considering the battery as the energy source. Simulations were performed in the Matlab/Simulink environment to validate the proposed system, along with experiments using a reduced-scale prototype controlled by the dSPACE platform. The results present the converter's proper operation with integration of the source and AC load, presenting improved features compared with conventional solutions in terms of reduced leakage of the current circulation from the AC load and reduced battery current ripple. [ABSTRACT FROM AUTHOR]

This paper investigates the development of pulse width modulation (PWM) schemes for three-phase quasi-Z-source inverters (qZSIs). These inverters are notable for their voltage boost capability, built-in short-circuit protection, and continuous input current, making them suitable for low-voltage-fed applications like photovoltaic or fuel cell-based systems. Despite their advantages, qZSIs confront challenges such as increased control complexity and a larger number of passive components compared to traditional voltage source inverters (VSIs). In addition, most existing PWM schemes for qZSIs lack the capability for independent control of the amplitude modulation index and duty cycle, which is essential in closed-loop applications. This study introduces innovative space-vector PWM (SVPWM) schemes, addressing issues of independent control, synchronization, and unintentional short-circuiting in qZSIs. It evaluates several established continuous and discontinuous PWM schemes, and proposes two novel decoupled SVPWM-based schemes that integrate dead time and in which the shoot-through occurrence is synchronized with the beginning of the zero switching state. These novel schemes are designed to reduce switching losses and improve qZSI controllability. Experimental validation is conducted using a custom-developed electronic circuit board that enables the implementation of a range of PWM schemes, including the newly proposed ones. The obtained results indicate that the proposed PWM schemes can offer up to 6.8% greater efficiency and up to 7.5% reduced voltage stress compared to the closest competing PWM scheme from the literature. In addition, they contribute to reducing the electromagnetic interference and thermal stress of the related semiconductor switches. [ABSTRACT FROM AUTHOR]

High-performance overmodulation strategies for voltage source inverters (VSIs) can further broaden the operation range of machines. Among them, Space Vector Pulse Width Modulation (SVPWM) is worth researching as it performs well in digital implementation. This paper presents a detailed comparison of various SVPWM overmodulation strategies and analysis of their performance. It firstly briefly elaborates fundamental laws of two subspaces of five-phase VSIs. Then, it focuses on several overmodulation strategies. Their corresponding basic principles and main characteristics are researched, and conclusions are given. In addition, differences and relationships between them are proved and summarized. Lastly, comparative simulations and experiments were carried out and verify that in the overmodulation region, the output voltage distortion degree increases with the increase in modulation ratio, and strategies with more control degrees of freedom (CDFs) are capable of better controlling the third harmonic subspace, which means that higher-quality output voltage waveforms would be obtained. [ABSTRACT FROM AUTHOR]

The paper proposes a nonlinear controller called dual super-twisting sliding mode command (DSTSMC) for controlling and regulating the rotor side converter (RSC) of multi-rotor wind power systems that use doubly-fed induction generators. It was proposed that this controller be developed as an alternative to the direct power control (DPC), which makes use of a pulse width modulation (PWM) strategy to regulate the RSC's functioning. Overcoming the power/current quality issue with the proposed technique (DPC-DSTSMC-PWM) is characterized by great robustness and excellent performance. The designed strategy was contrasted with the standard method of control and other methods already in use. So, the unique proposed control strategy's robustness, performance, efficiency, and efficacy in enhancing system characteristics were tested and validated in Matlab/Simulink. In both tests, the proposed method resulted in significant improvements, reducing active power ripples by 83.33%, 57.14%, and 48.57% in the proposed tests. When compared with the traditional regulation method, the reduction rates of reactive power ripples are 64.06%, 52.47%, and 68.7% in the tests. However, in contrast to the conventional method, the proposed tests showed a decrease of between 72.46%, 50%, and 76.22% in the value of total harmonic distortion (THD) of the provided currents. These ratios show how effective the proposed plan is in ameliorating and enhancing aspects of the energy system. [ABSTRACT FROM AUTHOR]

The emergence of quantum computers is having an impact on almost every field of engineering. Electrical drives, in particular, can benefit from the power of quantum computing. This paper presents a quantum version of the pulse-width modulation (PWM) algorithm, which is used widely to control electrical motors. The proposed algorithm is implemented using a real number comparator, which is novel to the authors' knowledge. Unlike other quantum comparators in the literature, which provide quantum versions of binary-based comparators, the suggested comparator compares real numbers ranging from 0 to 100%, making it more usable in practice for many industrial applications, particularly control. When applied to DC motor speed control, the quantum PWM controller achieved similar speed precision to the classical version, but with lower energy consumption and less switching. It could therefore significantly increase the lifetime of power devices while achieving similar control performance at lower energy consumption. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a new light‐emitting diode (LED) driver based on full‐bridge series resonant converter (SRC) is presented. In the proposed converter LED, load is placed in between DC source and the input side of the full‐bridge inverter which reduces the rectifier components of the SRC. The proposed converter reduces the number of diodes used for rectification and ensures zero voltage switching of the power switches which improves the efficiency of the converter. LED lamp current is regulated with phase‐shift pulse width modulation (PWM) of full‐bridge. Lamp illumination is controlled with PWM dimming. The operation and mathematical analysis of LED driver is presented. To validate the proposed concept, a 40‐W laboratory prototype is developed. Experimental results are presented. Peak efficiency of 93% is obtained. [ABSTRACT FROM AUTHOR]

Summary: This paper proposes a new floor function single carrier‐based modulated model predictive current control technique (FF‐SC‐M2PC2T) by considering conventional nine‐level T‐type packed U‐cell (9L‐TPUC) inverter topology. To get desired peak value of load current with low harmonic distortion, the finite control set‐based model predictive control technique (FCS‐MPCT) has been reported in the literature considering load dynamics and minimization of the cost function. However, inherently it suffers from variable switching frequency (VSF) of operation. To diminish this issue, an M2PC2T has been implemented and it provides a constant switching frequency (CSF) of operation. Especially coming to the modulation stage, most authors generally use level‐shifted pulse width modulation (PWM) techniques which inherently require more carriers, if‐else conditions, and additional logical gate blocks to generate particular level output. Hence, the control complexity increases as going to higher‐level inverter topologies. In this manuscript, a new simple floor function single carrier‐based pulse width modulation (FF‐SC‐PWM) technique has been proposed which applies to any single‐phase switched capacitor type multilevel inverter topology and it can be easily integrated with a predictive control algorithm to regulate the inverter output current (IOC). Finally, to check the effectiveness of the proposed control technique (PCT) in a closed loop, a laboratory prototype has been employed on 9L‐TPUC inverter topology with different static and dynamic case studies considering RL‐Load. [ABSTRACT FROM AUTHOR]

This paper proposes a new generalised boost integrated multilevel inverter (MLI) with reduced components. The proposed MLI is developed by using a modified boost integrated switched capacitor unit, which provides four-level output from each cell. The operation of the proposed MLI for symmetrical 17-level operation with sinusoidal pulse width modulation & nearest level control and asymmetrical 31-level operation with NLC is explained and validated experimentally. The experimental results of static and dynamic load conditions are analysed and discussed in detail. In addition, the proposed topology is compared with recent boost MLI topologies in terms of component count, device stress, efficiency, capacitor size and cost. From the comparative study, it is evident that the proposed MLI provides features such as reduced component count, capacitors size, overall cost and improved voltage gain. [ABSTRACT FROM AUTHOR]

Purpose: Static inverters are very important for the emergency energy distribution system of aircraft and similar machines. At the same time, the electrical energy produced at high frequency for electrical devices is used to reduce the weight of the cables in the aircraft and spacecraft because of the skin effect. In the high-frequency system, a thinner cable cross-section is used, and a great weight reduction occurs in the aircraft. So, fuel economy, less and late wear of the materials (landing gear, etc.) can be obtained with decreasing weight. This paper aims to present the development of a functional multilevel inverter (FMLI) with fractional sinus pulse width modulation (FSPWM) and a reduced number of switches to provide high-frequency and quality electrical energy conversion. Design/methodology/approach: After the production of FSPWM for FMLI with a reduced component, which, to the best of the authors' knowledge, is presented for the first time in this study, is explained step by step, and eight operating states are given according to different FSPWMs operating the circuit. The designed inverter and modulation technique are compared by testing the conventional modular multilevel inverter on different loads. Findings: According to application results, it is seen that there is a 50% reduction in cross-section from 100 Hz to 400 Hz with the skin effect. At 1000 Hz, there is a 90% cross-section reduction. The decrease can be in cable weights that may occur in aircraft from 10 kg to 100 kg according to different frequencies. It causes less harmonic distortion than conventional converters. This supports the safer operation of the system. Compared to the traditional system, the proposed system provides more amplitude in converting the source to alternating voltage and increases the efficiency. Practical implications: FSPWM is developed for multilevel inverters with reduced components at the high frequency and cascaded switching studies in the power electronics of aircraft. Social implications: Although the proposed system has less current and power loss as mentioned in the previous sections, it contains fewer power elements than conventional inverters that are equivalent for different hardware levels. This not only reduces the cost of the system but also provides ease of maintenance. To reduce the cable load in aircraft and create more efficient working conditions, 400 Hz alternative voltage is used. The proposed system causes less losses and lower harmonic distortions than traditional systems. This will reduce possible malfunctions and contribute to aircraft reliability for passengers and cargo. As technology develops, it is revealed that the proposed inverter system will be more efficient than traditional inverters when devices operating at frequencies higher than 400 Hz are used. With the proposed inverter, safer operation will be ensured, while there will be less energy loss, less fuel consumption and less carbon emissions to the environment. Originality/value: The proposed inverter structure shows that it can provide energy transmission for electrical devices in space and aircraft by using the skin effect. It also contains less power elements than the traditional inverters, which are equivalent for different levels of hardware. [ABSTRACT FROM AUTHOR]

The silicon carbide (SiC) inverter brings great advantages to the motor drive systems of new energy vehicles; however, severe challenges to the bearings also happen. The high dc bus voltage and switching frequency of SiC inverter can increase the discharge frequency and energy when the bearing grease film collapses. As a result, the bearing suffers severe electric corrosion, and the service life of the motor drive system can be shortened. In this paper, the characteristics of common-mode voltage and bearing voltage are analyzed, firstly under space vector pulse width modulation (SVPWM). After that, the common-mode equivalent circuit model of the motor drive system is established. The frequency characteristics of bearing voltage are revealed, and the safe working area is determined. Then, the frequency characteristics of bearing voltage and current are verified based on IGBT and SiC inverters in experiments. After that, by designing a common-mode filter, the bearing voltage and current are significantly attenuated. Furthermore, the active zero state PWM (AZSPWM) is adopted to reduce the common-mode voltage from the inverter. At the same time, combined with the common-mode filter, the bearing voltage and current are further reduced. The experimental results show that the switching frequency has a decisive effect on the amplitude of bearing voltage and current. The bearing voltage can be attenuated to around half of the reference bearing voltage by using the common-mode filter and AZSPWM strategy, respectively. The combination of the common-mode filter and AZSPWM strategy can reduce the bearing voltage to around one-fourth of the reference bearing voltage, which can effectively reduce the breakdown time and discharge energy of the grease oil film. [ABSTRACT FROM AUTHOR]

Summary This paper compares four modulation strategies applied to five‐phase voltage source inverters (5PH‐VSI). The modulation strategies under investigation are sine wave pulse width modulation (S‐PWM), fifth‐harmonic injection PWM (FH‐PWM), space vector‐PWM using two large vectors (2V‐SVPWM), and space vector‐PWM using two medium and two large vectors (4V‐SVPWM). The study utilizes simulations to analyze the results based on four performance criteria: low‐order harmonics (LOH), maximum modulation index (MMI), common mode voltage (CMV), and total harmonic distortion (THD) under balanced and unbalanced load. To validate the simulation results for these criteria, an experimental test‐bench is employed, which includes a 5PH‐VSI feeding an R‐L load, and controlled by a low‐cost STM32F4‐DISCOVERY microcontroller board. Additionally, a mathematical approach is used to calculate the total thermal losses (TTL) then simulations are performed using Piecewise Linear Electrical Circuit Simulation (PLECS) software to assess the modulation schemes based on additional thermal performance criteria: conduction losses (CL), switching losses (SL), TTL, the efficiency, and the maximum permissible heat sink thermal resistance (MPHTR) at the steady‐state regime. The results indicate that the 4V‐SVPWM method demonstrates superior efficiency in terms of THD. Furthermore, it showcases the lowest TTL at high switching frequencies, allowing for the best efficiency and minimizing MPHRT, therefore providing the largest margin for the heat sink thermal resistance design. On the other hand, the 2V‐SVPWM offers the highest MMI, but this comes at the cost of high TTL and some LOHs appearing. In addition, it exhibits the highest CMV for unbalanced load. S‐PWM and FH‐PWM offer the advantage of simpler implementation. [ABSTRACT FROM AUTHOR]

This paper deals with an adaptive control of two driving-wheels electric vehicle. Indeed, an Indirect Field Oriented Control of two induction motors fed simultaneously by Nine Switches Inverter has been included. Hence, to ensure an independent control of the two induction motors, a specified Space Vector Pulse Width Modulation strategy for Nine Switches Inverter is developed. For this, a switching table and a switch-over bloc are proposed. The effectiveness of the proposed control strategy is evaluated and validated by simulations and experimental tests. In this context, the developed system can be used as a promising solution for an independent control of two driving wheels of electric vehicle using a software differential. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a new floor function (F2) single‐carrier (SC)‐based modulated model predictive current control technique (M2PC2T) has been proposed by considering the conventional single‐phase five‐level packed U‐cell (PUC5) inverter topology. Generally, to regulate the output current, the finite control set‐based MPC technique without a modulator inherently operates with variable switching frequency, and it is unsuitable for industrial applications. To alleviate this, authors have implemented M2PC2T, which provides constant switching frequency of operation. In this technique, generally, the predictive algorithm has been integrated with any modulation stage. However, while the implementation of pulse width modulation (PWM) techniques, most authors have used conventional PWM techniques which further increases the control complexity as the level number increases. In this manuscript, a simple and generalized F2‐SC‐PWM technique has been proposed and integrated with the predictive algorithm. This PWM technique implementation process is very simple as compared with all conventional PWM techniques since even if the level number increases, the number of modulating and carrier signals is always only one. Finally, the complete closed‐loop control technique is called a generalized F2‐SC‐M2PC2T which is suitable for all stiff direct current (dc) sources and switched capacitor‐type multilevel inverter (MLI) topologies. The proposed control technique (PCT) has been experimentally verified with different transient and steady‐state case studies by considering resistive‐inductive load. [ABSTRACT FROM AUTHOR]

Summary: This paper proposes a step‐up three‐phase multilevel inverter based on switched capacitor (SC) cells. The prominent features of this inverter are the reduction of the number of components (such as switches, capacitors, and sources) and the ability to boost the voltage. Also, the self‐voltage balancing of the capacitors of this inverter is one of the other features of this inverter. The level‐shifted pulse width modulation (LS‐PWM) method has been used for switching, making the output currents' total harmonic distortion (THD) low. The article has presented the experimental results of this inverter with a three‐phase induction motor with a power of 1.1 kW as a load. [ABSTRACT FROM AUTHOR]

Summary: A new floor function single carrier‐based modulated model predictive current control (F2‐SCM2PC2) technique has been proposed in this paper by considering traditional single‐phase quadruple boost switched capacitor‐based multilevel inverter (QB‐SCMLI) topology. Conventionally, the implementation process of single modulating and single carrier‐based pulse width modulation (PWM) techniques are very much complex and finite control set‐based model predictive control (FCS‐MPC) technique inherently operates with variable switching frequency (VSF) operation, which is not suitable for industrial applications. To alleviate the aforementioned issues, a new generalized closed‐loop F2‐SCM2PC2 technique has been proposed. It consists of a simple PWM implementation process and can easily be integrated with a predictive algorithm, thereby providing a constant switching frequency (CSF) of operation. The particular single modulating and single carrier‐based PWM technique with floor function is also suitable for low and high switching frequency (LSF‐HSF) operations. The validation of floor function‐based PWM technique in open‐loop and closed‐loop F2‐SCM2PC2 techniques has been effectively verified through experimentation on QB‐SCMLI topology with consideration of resistive–inductive load. [ABSTRACT FROM AUTHOR]

Nowadays, multilevel inverter (MLI)-based induction heating (IH) technology is the best-suited option in many domestic, commercial and medicinal applications because of its higher efficiency, low cost, fast heating and lower electromagnetic interference (EMI). This paper presents reduced components count high-frequency (HF) single phase five-level (5-L) MLI for IH applications. The working methodology of the proposed system has been analyzed in the multicarrier phase disposition pulse width modulation (MC-PD-PWM) method in high switching frequency i.e., 10 kHz. In addition, the proposed topology can produce output voltage twice of input voltage without any external source. Moreover, the detailed power loss and reliability analysis have been evaluated for the proposed system. In terms of switch count and efficiency, the single-phase 5-L inverter architecture is compared to some conventional and current topologies. Finally, to validate and justify the operation of the proposed system, the simulation and experimental results of five-level inverter are presented. [ABSTRACT FROM AUTHOR]

This paper proposes low and high frequency control techniques for asymmetrically switched cascaded multilevel inverters (MLI). Initially, Low frequency-based switching angle calculation methods are proposed for the suggested topology. Then high frequency-based Multi-carrier pulse width modulation (MCPWM) techniques are used to control the switching states of multilevel inverters for asymmetrical sources. The proposed multilevel inverter is a reduced switch topology with a modular version realized. From the modular version of the topology, three asymmetrically switched (7, 13 & 21) levels are simulated by MATLAB/Simulink environment and comparisons among themselves are also considered according to method of switching techniques and power quality, i.e. total harmonic distortion (THD). The designed inverters are recommended for photovoltaic power generation as they are suitable to integrate separate DC power sources. The inverters are designed and simulated with a proper simulation environment and experimentally verified through hardware in loop (HIL) using OPAL-RT (OP-5600) testbed. [ABSTRACT FROM AUTHOR]