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A unified unsaturated-reluctance-based wide speed range sensorless control method for switched reluctance machines (SRMs) is proposed in this paper. Firstly, the sensitivity analysis of the estimated position to the possible reluctance calculation error is analyzed. This analysis reveals the feasible regions with low sensitivity and low risk of entering saturation. Then, the unsaturated reluctance in these feasible regions is obtained and modeled. A simple second-order rational expression is proposed to fit the highly nonlinear unsaturated reluctance curve. With this simple model, the rotor position can be analytically calculated only by solving a simple quadratic problem. Based on the above-presented analysis, a wide-speed range sensorless control is developed. The rotor position is universally estimated from the real-time reluctance value and the proposed analytical model. The high-frequency voltage injection and normal conduction phase are combined to calculate the phase reluctance over the wide-speed range. The concerns of calculating reluctance at the low-speed range are also discussed. A 5.1 kW four-phase 8/6 SRM is used to verify the proposed method. Various steady state and transient state experimental results prove the effectiveness of the proposed sensorless control method.

Electric vehicles require high-power machines, so reducing power loss becomes crucial. Compared to space vector modulation, synchronous optimal pulse width modulation (SOP) has several advantages in high-speed applications, like the capability to operate at a very low switching frequency with lower total harmonic distortion, and reduced losses. This article presents a comprehensive review after performing a systematic investigation on different inverter topologies, including two-level voltage source inverters and multilevel inverter topologies with SOP as the modulation scheme. Several optimal pulsewidth methods will be studied along with SOP design methods, including steady state and dynamic switching. More emphasis is given to the various challenges faced in implementing SOP, followed by future trends. IEEE

This paper presents a simple and practical method to estimate the lumped radial force characteristics for the switched reluctance machines (SRMs). Firstly, the relationship between the square root of the lumped radial force and the flux-linkage is discussed and analyzed. With the geometry data of the studied SRM, the above relationship under nominal airgap length and nominal material magnetic property conditions can be obtained through the finite element analysis (FEA) software. Since the radial flux density dominates the magnitude of the radial force and it concentrates on the overlapping area, the above relationship is analyzed to be roughly held when the airgap length and/or material magnetic property vary. Based on this relationship obtained from FEA and the actual measured flux-linkage characteristics, the lumped radial force can be easily reconstructed for the actual SRMs regardless of the possible airgap length variation and material magnetic property deviation during the manufacturing process. Simulation results on the 8/6 SRM and 12/8 SRM verify that the proposed method provides good radial force estimation results when the airgap length is reduced or increased up to 50%. Superior estimation results are also observed on the condition that the magnetic BH curve is linearly varied by ±25%. The accurate and simple radial force estimation method proposed in this paper provides a solid basis for the radial-force-shaping-based advanced control methods to suppress the acoustic noise.

The vibration/noise and torque ripple are two inherent issues for switched reluctance motors (SRMs), one of the effective methods to address these two issues is flattening both the total radial force and total torque. In this paper, an optimized quadratic-sharing-function-based radial force and torque simultaneous flattening method is proposed for SRMs. Firstly, the features of the radial force and torque characteristics are analyzed without considering saturation. Then, with these unique and specific features, four regions are defined to develop the simultaneous radial force and torque control method based on the linear sharing functions. To incorporate the saturation effects in the proposed method, the quadratic sharing functions are adopted. The proper parameters of the quadratic sharing functions and the region definition at different operating conditions are obtained through the genetic algorithm (GA) optimization. The switching angles and reference current of the conventional current chopping control (CCC) method are also optimized by GA for fair comparison purpose. Extensive simulation results are presented in this paper, and these results prove the effectiveness and superiority of the proposed method regarding the simultaneous radial force and torque control. © 2022 IEEE.

Synchronous optimal pulse-width modulation (SOPWM) is an effective solution to reduce switching frequency without increasing the current distortion. This method is widely used along with stator flux tracking in traction applications of induction motors. However, stator flux tacking is not an ideal control technique for permanent magnet synchronous motors (PMSMs). This paper studies SOPWM with stator current tracking for PMSM traction applications. Stator current tracking with SOPWM suffers poor steady-state performance when the PMSM operates around discontinuity of the switching angles due to the voltage disturbance generated from current harmonics. This problem is usually solved by using continuous switching angles. However, this approach brings more overall current distortion due to sub-optimal switching angles. To address this issue, a novel hysteresis control-based SOPWM scheme with continuous switching angles is proposed. Preliminary simulation results indicate that the proposed method can offer low current distortion compared to conventional and continuous SOPWMs. © 2022 IEEE.

In this article, a general-purpose low-speed position estimation scheme using pulse injection is proposed for sensorless switched reluctance motor (SRM) drives. For the conventional low-speed sensorless control methods, magnetic characteristics are often used for position estimation, but it requires offline measurement and reduces the generality of sensorless control algorithms. To solve the issue, a new position estimator based on a regional phase-locked loop (RPLL) is designed. The approach utilizes a self-commissioning process to capture the unsaturated inductance adaptively at the initial stage. The RPLL is then adopted to estimate the full-cycle rotor position from the idle-phase inductance during sensorless operation. The speed-reversible sensorless control capability is also realized by a simple heterodyne design. Furthermore, stability analyses and parameter design are given to prove the robust local stability and convergence. Finally, comparative experimental validation is conducted on a 5.5-kW 12/8 SRM setup to verify the proposed method's effectiveness under both no-load and load conditions.

High-speed position-sensorless control of switched reluctance motor (SRM) drives is often realized by searching a priori flux linkage lookup table. However, obtaining the nonlinear flux linkage characteristic requires time-consuming offline measurement and occupies large memory storage. To deal with this problem, this article proposes a new position estimation scheme for SRM drives without using any magnetic characteristics. This feature is achieved by using a quadrature flux estimator (QFE) that can extract the fundamental flux and its quadrature signal from the real-time calculated flux linkage. The flux bias and flux harmonics can also be suppressed by the QFE’s adaptive bandpass capability. Therefore, the proposed method can reduce the nonlinearity in SRM flux linkage and derive simple sine–cos position signals. Afterward, the rotor position and speed can be estimated from the orthogonal flux signals using a three-phase phase-locked loop. To baseline the advantages, comparative experimental validation with the conventional method is conducted on a three-phase 12/8 SRM test bench. The results show that the proposed scheme can achieve the same estimation accuracy as the conventional method even though no magnetic characteristics are used.

In this article, a low-ripple continuous control set (CCS) model predictive torque control (MPTC) method for switched reluctance machines (SRMs) is proposed. The inherent high nonlinearity of the SRMs makes it difficult to solve the optimization problem in the CCS MPTC algorithm analytically. To address this issue, an equivalent linear SRM model is adopted, and the cost function is also properly modified. Then, with the torque boundary values provided by executing the voltage vectors of an improved switching table, the optimization problem in the CCS MPTC method becomes simple and analytically solvable. The Lagrange multiplier method is employed to solve this optimization problem analytically and generate the optimum torque reference values for the active phases. Based on the estimated torque variation rates, the duty cycles for each phase are calculated. Extensive simulation and experimental tests are carried out in a four-phase 8/6 SRM setup. These testing results reveal that the proposed CCS MPTC method shows much lower torque ripples and current ripples in a wide speed range with a low computational burden than the existing finite control set MPTC methods.

In this article, a novel model predictive torque control (MPTC) method for switched reluctance machines (SRMs) is proposed based on the equivalent linear SRM model and the improved switching table. First, an improved switching table with only six switching states is developed based on the inductance characteristics. The adoption of this improved switching table not only reduces the computational burden by 25% but also improves the torque control performance and system efficiency at high-speed region. However, the look-up-table (LUT) based MPTC methods suffer from occupying numerous storage space. To ease this issue, the simple linear SRM model is utilized. The flux-linkage and torque equivalent transformations are introduced to address the difference between the linear and nonlinear SRM models. With these transformations, the MPTC realized on the linear SRM model is proposed. Compared to 1530 storage units consumption to store three two-dimensional (2-D) LUTs in the LUT-based MPTC methods, the proposed method only occupies 228 storage units. Experimental results on an 8/6 SRM setup verify that the proposed method effectively eliminates the commutation torque ripple with lower execution time, less storage space, and improves the torque control performance at a highspeed range compared with the conventional LUT-based method.

Optimal pulse patterns (OPPs) have many advantages for permanent magnet synchronous motor (PMSM) drives, such as low switching frequency, and low current harmonic distortion at medium to high speeds. Selective harmonic mitigation is an effective approach to generate optimal switching pulse patterns by minimizing the entire harmonic content instead of eliminating individual harmonics. A proper offline optimization method is required for selective harmonic mitigation to maximize the power utilization of PMSMs. This paper discusses two optimization techniques: 1) genetic algorithm (GA) and 2) FMINCON solver for obtaining the OPPs for a two-level inverter. Both the methods are studied with different pulse number to calculate the optimal switching angles that can provide less total harmonic distortion (THD) of phase currents. Comparative simulations are performed to validate the effectiveness of the optimization approach and it is found that FMINCON solver can optimize the switching angles better than GA with an approximately 4% reduction in the phase current THD. © 2022 IEEE.

Switched reluctance motors (SRMs) are promising traction machine candidates for electric vehicle powertrains and industrial driving systems due to their rugged construction and high efficiency. Precise speed and torque control of SRMs require real-time rotor position information from mechanical position sensors. With the advantages of lower costs and position sensor fault-tolerant capability, various position-sensorless control strategies have been developed for SRM drives in the past decades. This article presents a review of the state-of-the-art sensorless control schemes over a wide speed range. Low-speed methods based on high-frequency pulse voltage injection and high-speed methods based on fundamental excitation are summarized to give readers a systematic categorization. An in-depth comparison of major sensorless control algorithms in estimation accuracy, robustness, universality, and parameter sensitivity is presented. Finally, the existing challenges and future trends are discussed.

This paper presents a simple and practical method to estimate the lumped radial force characteristics for the switched reluctance machines (SRMs). Firstly, the relationship between the square root of the lumped radial force and the flux-linkage is discussed and analyzed. With the geometry data of the studied SRM, the above relationship under nominal airgap length and nominal material magnetic property conditions can be obtained through the finite element analysis (FEA) software. Since the radial flux density dominates the magnitude of the radial force and it concentrates on the overlapping area, the above relationship is analyzed to be roughly held when the airgap length and/or material magnetic property vary. Based on this relationship obtained from FEA and the actual measured flux-linkage characteristics, the lumped radial force can be easily reconstructed for the actual SRMs regardless of the possible airgap length variation and material magnetic property deviation during the manufacturing process. Simulation results on the 8/6 SRM and 12/8 SRM verify that the proposed method provides good radial force estimation results when the airgap length is reduced or increased up to 50%. Superior estimation results are also observed on the condition that the magnetic BH curve is linearly varied by ±25%. The accurate and simple radial force estimation method proposed in this paper provides a solid basis for the radial-force-shaping-based advanced control methods to suppress the acoustic noise.

This paper presents the application of Model Predictive Control (MPC) in high-performance drives. A wide variety of machines have been considered: induction machines, synchronous machines, linear motors, switched reluctance motors, and multiphase machines. The control of these machines has been done by introducing minor and easy-to-understand modifications to the basic predictive control concept, showing the high flexibility and simplicity of the strategy. The second part of the paper is dedicated to the performance comparison of MPC with classical control techniques such as field-oriented control and direct torque control. The comparison considers the dynamic behavior of the drive and steady-state performance metrics such as inverter losses, current distortion in the motor, and acoustic noise. The main conclusion is that MPC is very competitive concerning classic control methods by reducing the inverter losses and the current distortion with comparable acoustic noise.

Rotor position and speed estimation methods are consolidated to reduce the cost and volume of permanent magnet synchronous motor (PMSM) sensorless control drives while maintaining high performance. Advanced nonlinear algorithms require accurate design for precise estimation tracking throughout the entire PMSM operation range. This paper presents a broad review of the main high-speed estimation methods for sensorless PMSM drives. First, the stability constraints and design methodologies of the main estimation techniques presented in the literature are discussed. In the second part, it is investigated the new observer design trends, which are used under non-ideal conditions, such as robustness to distortions, the effects of parameter variation, sensorless parameter estimation, and low sampling-frequency-to-speed ratio operation. Future trends on the design of observers for high-speed sensorless PMSM drives are also discussed.

In this article, a novel online optimal tracking method is proposed for permanent magnet synchronous machine drives for maximum torque per ampere (MTPA) and flux-weakening (FW) operations. The conventional model-based optimal tracking methods impose heavy computational burden, because the optimality criteria are usually used along with related boundaries to develop different optimization problems for different operation regions. Compared with the conventional methods, the proposed method reduces the mathematical complexity of the optimization problem and improves the computational efficiency in real-time implementation. Only one optimization problem is solved in both MTPA and FW regions, while the enhanced projection operations are developed to ensure the current references are within the voltage and current constraints. Magnetic saturation, phase winding resistance, nonlinearity of the inverter, and dc-link voltage variation are all taken into consideration. The feasibility of the proposed online optimal tracking method has been validated on an interior permanent magnet synchronous machine (IPMSM) test bench with an off-the-shelf motor control unit. The execution time and convergence rate of the proposed method have also been evaluated with benchmark conventional methods and presented in this article.

Good current tracking is beneficial to the torque ripple suppression methods like current profiling techniques for the switched reluctance machines (SRMs). An intersection-method-based current controller for the SRM with robust tracking performance is proposed in this article. First, with the aid of the predicted current at the next sampling instant, the prestored reference current, and the flux-linkage information, the required duty cycle for the next control period under specific reference current is estimated through the intersection method. To compensate for the difference between the adopted flux-linkage model and the real ones inside the machine, a Lyapunov-based adaptive flux-linkage observer is presented. Hence, the heavy dependence issue on the accurate flux-linkage model for the current controller is resolved. With the above techniques, robust reference current tracking is achieved in a simple form and only one observer gain. Besides, a balanced switching scheme is presented to reduce the switching frequency requirement of the power transistors and evenly distribute the switching losses. Extensive experimental tests have been carried out on a four-phase 5.1-kW 8/6 SRM setup for the proposed method and conventional current control methods at different operation conditions. These testing results verified the effectiveness of the proposed method.

This article proposes a computationally efficient position-sensorless control scheme for medium- and high-speed permanent magnet synchronous motor (PMSM) drives under distorted conditions. An adaptive comb observer (ACO) is designed for accurate position estimation by eliminating primary distortions simultaneously, including dc offsets from current measurement, odd harmonics caused by inverter nonlinearity, and even harmonics due to the modulation. A frequency-locked loop based on the Lyapunov stability theory is embedded in the ACO to ensure the observer's stability and fast convergence of the estimated variables. Compared with conventional adaptive position observers that usually require high-order filtering networks, the proposed scheme only consists of four delay operators and does not require complicated discretization. Therefore, it can simplify digital implementation and reduce the computational burden of the sensorless algorithm. To validate the effectiveness of the proposed observer, comparative experiment tests of the proposed ACO and conventional methods are performed on a 15-kW PMSM setup.

In this article, a time-efficient torque shaping technique for the switched reluctance machines is proposed to reduce the torque ripples while optimizing the copper loss. To reduce the computational time for solving the time-consuming bi-objective optimization problem, an efficient and desirable linear space for the SRM is utilized through the torque mapping between the linear space and nonlinear space. The feasible regions and properties of this torque mapping for SRM are studied in detail first. Then, based on this torque mapping, the current reference is generated by solving a convex optimization problem in the linear space and later converted to the current reference in nonlinear space. Compared to the traditional method that only adopts nonlinear space, the proposed current reference generation method requires less than 10% of the time. Furthermore, the proposed method saves more than 70% time consumed by the traditional method for the bi-objective optimization problem but possesses the similar torque ripple reduction performance. The effectiveness of the proposed method has been verified by extensive simulation and experimental tests on a four-phase 5.1 kW 8/6 SRM setup.

With the increasing environmental concerns, a paradigm shift towards electric and hybrid electric vehicles is expected. Switched Reluctance Motors (SRMs) have emerged as a viable competitor to other established electrical machines. SRMs are known for their simple construction, robustness, inherent fault tolerant structure and low production and maintenance costs. Moreover, the machine has gained interest due to the absence of permanent magnets or windings in the rotor structure, which significantly reduces production costs when compared to other electric motors. The SRM, however, present some known drawbacks, such as increased torque ripple and acoustic noise production, as well as a highly nonlinear behavior. Through the use of adequate control strategies, however, the main challenges of the machine can be overcome. Thus, this paper presents a state-of-the-art review of the advanced control of SRMs, encompassing current regulation strategies, torque control strategies and vibration suppression techniques. First, two categories of current controllers are reviewed: model-independent and model-based. Next, indirect and direct torque control methods are explored. Then, three approaches to vibration suppression are discussed, namely active cancellation, current profiling and direct instantaneous force control. Lastly, a summary of each topic is presented and suggestions of future research topics are listed.

The article proposes a nonlinear state observer (NSO) for robust position-sensorless control of switched reluctance motor (SRM) drives over medium- and high-speed range. A classical reference flux-linkage method is adopted to capture a feature position of the SRM, which avoids the use of 3-D magnetic characteristics and has better universality. However, the estimation accuracy of this method would be deteriorated due to flux-linkage errors. To ease the problem, the NSO is developed to enhance the robustness against flux-linkage distortions for more accurate position and speed estimation. This observer can first reconstruct complete position information from a low-resolution feature position. The adverse impact of flux-linkage errors on position estimation is then investigated through a novel small-signal approximation and suppressed by an augmented state estimator. Afterward, a parameter design scheme is given to ensure the observer's stability and improve the capability in distortion suppression. To baseline the performance, comparative experimental validation between the proposed NSO and a widely used linear prediction method is conducted on a 12/8 SRM setup. The results show that the proposed strategy can improve the overall position-sensorless control performance in both the steady and transient states.

This article presents a general-purpose full-speed sensorless control scheme for interior permanent magnet synchronous motors (IPMSMs). By applying a quadratic extended back electromotive force (QBEMF) model, the injection-based and model-based position estimations can be combined into a universal sensorless control strategy for the full-speed operation. At low speed, the QBEMF model acts as a self-demodulator that can extract position information from arbitrary high-frequency currents without using digital filters. Therefore, it is suitable for any type of injection signals and can eliminate the adverse effect of filters. When the injection is removed at high speed, the same QBEMF model can still be used for position estimation, thereby solving the conventional transition issue from low-speed to high-speed sensorless control. In consequence, a unified algorithm is designed to achieve arbitrary injection for low-speed sensorless control and seamless transition across full-speed region. The proposed scheme is hence simpler and more effective compared to conventional full-speed sensorless methods. Finally, the feasibility of the proposed estimation algorithm is verified for a 15-kW IPMSM drive.

This study presents a numerical modelling approach for the prediction of vibration and acoustic noise for a 24/16 traction switched reluctance machine (SRM). The numerical modelling includes the simulation of electromagnetic force in JMAG, the calculation of natural frequencies and the simulation of vibration and acoustic noise in ACTRAN. Considerations in the modelling of geometries, meshing and contacts of the 24/16 SRM are discussed to ensure the accuracy of the numerical simulation. Two-dimensional fast Fourier transform (FFT) is applied to the radial nodal force at the stator pole tip to analyse the dominant harmonics. FFT is also applied to the simulated surface displacement of the housing and the sound pressure at 2000 rpm to analyse their dominant frequency components. The dominant harmonics for the vibration and acoustic noise at 2000 rpm are confirmed. The numerical modelling method presented in this study can also be applied to the other SRMs and electric machines to predict the vibration behaviour and the radiated acoustic noise., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., DC systems, Energy conversion & Storage

Model-based position-sensorless control of interior permanent magnet synchronous motors (IPMSMs) is promising for high-speed operation, besides the fact that the estimation accuracy degrades by dc errors from integration, measurements, and parameter uncertainties. In this article, a new complex-coefficient adaptive disturbance (CCAD) observer based on the back electromotive force estimation is proposed. The proposed CCAD observer has a bandpass characteristic and possesses resonating peak response at the corner frequency which is adapted to the synchronous rotor frequency. This adaptive resonant frequency effectively improves the robustness to dc errors, without magnitude loss and phase delay. The proposed observer is also compact and has lower order as compared to the other bandpass observers, and that substantially benefits in the embedded implementation. To configure the proposed CCAD observer, a reverse observer design scheme is analyzed. The stability of the observer is guaranteed based on a speed adaptation law, and small-signal approximation is then applied to linearize the proposed observer for parameter design and dynamic analyses, which have not been well discussed in literature. The proposed method is verified by experiments for a 15 kW IPMSM drive.

Aiming at tolerating common electric faults of multiphase motor drives comprehensively and minimizing the adverse impacts from the remedial scheme itself, a diagnosis-free self-healing scheme is put forward for the open-circuit faults of dual three-phase permanent-magnet synchronous motor (PMSM) drives. First, the self-healing mechanisms of dual three-phase PMSM drives are analyzed in detail. On the basis of theoretical analysis, the repressed self-healing capability of the dual three-phase PMSM drives is fully released by optimizing the current references on harmonic subspace. Since the diagnosis process is not required in the proposed self-healing scheme, the misdiagnosis problem and the prolonged damage caused by the additional time cost of diagnosis can be fundamentally avoided. The proposed self-healing scheme can be generally applied to open-switch faults, single open-phase faults, and multiple open-phase faults in the multiphase motor drives. No change is required for the machine model, modulation strategy, or control framework under different open-circuit faults. Thus, the complex transition strategies among different fault-tolerant control methods for different faults can be avoided, and the adverse impacts from the remedial scheme itself can be minimized. Experimental verification is presented to prove the validity of the proposed self-healing scheme.

Model-based state-of-charge (SOC) and state-of-health (SOH) estimation for lithium-ion batteries has been widely applied in electrified vehicles, while the SOC and SOH estimators are highly coupled and nonlinear in conventional techniques. This leads to a bulky design of observer network and complicates the stability analyses. In this article, a new reduced-decoupling SOC and SOH coestimation algorithm based on convex optimization is proposed. This scheme estimates the battery SOC from the battery model and does not require the classic Coulomb-counting method. Therefore, it can decouple the capacity estimation from the SOC estimator and reduce the strong interaction existing in conventional coestimation methods. Besides, all state variables can be solved together by one estimator, which is straightforward and avoids the complicated observer network. Owing to the decoupling design, the stability of the proposed method becomes more intuitive and can be always guaranteed according to the convexity analysis without using other stabilizing approaches. In consequence, a weak-interaction and robust coestimation algorithm of SOC and SOH can be realized by the proposed technique. The experiments on a 5.4-Ah lithium polymer battery are implemented to validate the feasibility of the algorithm.

This study presents a numerical modelling approach for the prediction of vibration and acoustic noise for a 24/16 traction switched reluctance machine (SRM). The numerical modelling includes the simulation of electromagnetic force in JMAG, the calculation of natural frequencies and the simulation of vibration and acoustic noise in ACTRAN. Considerations in the modelling of geometries, meshing and contacts of the 24/16 SRM are discussed to ensure the accuracy of the numerical simulation. Two-dimensional fast Fourier transform (FFT) is applied to the radial nodal force at the stator pole tip to analyse the dominant harmonics. FFT is also applied to the simulated surface displacement of the housing and the sound pressure at 2000 rpm to analyse their dominant frequency components. The dominant harmonics for the vibration and acoustic noise at 2000 rpm are confirmed. The numerical modelling method presented in this study can also be applied to the other SRMs and electric machines to predict the vibration behaviour and the radiated acoustic noise., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., DC systems, Energy conversion & Storage

This paper presents a comprehensive state-of-the-art review of the modeling and analysis methods for the multidisciplinary design of electric motors for various applications including vehicular power and propulsion systems and electrified powertrains. It covers the important aspects of different engineering domains, such as dynamic modeling, loss calculations, demagnetization analysis, thermal modeling, acoustic noise and vibration analysis, and mechanical stress modeling. This paper intends to guide the electric motor designers through examples and results on how to apply different analysis techniques on electric motors., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., DC systems, Energy conversion & Storage

A dual three-phase machine with interior permanent magnet rotor and distributed winding has been studied and compared to a commercial automotive traction machine, the Nissan Leaf IPM machine. The performance of the two designs are compared for typical traction operating points, via high torque, low speed and low torque, high speed, and constant power field weakening operation. The dual three-phase machine is shown to have improved torque density and torque quality without compromising efficiency.

This paper presents a comprehensive state-of-the-art review of the modeling and analysis methods for the multidisciplinary design of electric motors for various applications including vehicular power and propulsion systems and electrified powertrains. It covers the important aspects of different engineering domains, such as dynamic modeling, loss calculations, demagnetization analysis, thermal modeling, acoustic noise and vibration analysis, and mechanical stress modeling. This paper intends to guide the electric motor designers through examples and results on how to apply different analysis techniques on electric motors., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., DC systems, Energy conversion & Storage

This paper proposes an advanced dynamic modelling approach of the mutually coupled switched reluctance motor (MCSRM) in the dq reference system that can consider saturation, cross-coupling, and spatial harmonics. Different topologies and their operating principles are investigated and an idealized dq -model considering the inductance harmonics is derived. A dynamic model is built based on flux-current lookup tables (LUTs) obtained from finite element analysis (FEA). A simplified method to inverse the two-dimensional LUTs is proposed. A fast computation approach is used to reduce the number of FEA simulations and calculation time to obtain the LUTs. Motor dynamic performances at different speeds are simulated by using the proposed dynamic model and the results are investigated and verified by FEA. The motor dynamic behavior can be accurately obtained in a short simulation time by using the proposed approach. Experiments are carried out on a 12/8 MCSRM, showing good accuracy of the proposed model., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., DC systems, Energy conversion & Storage

This paper proposes an advanced dynamic modelling approach of the mutually coupled switched reluctance motor (MCSRM) in the dq reference system that can consider saturation, cross-coupling, and spatial harmonics. Different topologies and their operating principles are investigated and an idealized dq -model considering the inductance harmonics is derived. A dynamic model is built based on flux-current lookup tables (LUTs) obtained from finite element analysis (FEA). A simplified method to inverse the two-dimensional LUTs is proposed. A fast computation approach is used to reduce the number of FEA simulations and calculation time to obtain the LUTs. Motor dynamic performances at different speeds are simulated by using the proposed dynamic model and the results are investigated and verified by FEA. The motor dynamic behavior can be accurately obtained in a short simulation time by using the proposed approach. Experiments are carried out on a 12/8 MCSRM, showing good accuracy of the proposed model., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., DC systems, Energy conversion & Storage

As a cost-effective, healthy, and environmentally friendly personal mode of transportation, electric bicycles (E-bikes) are gaining an increasing market share from conventional bicycles and automobiles. Considering the legal rules in Ontario, Canada, a 500W motor makes the E-bike more attractive for travelling use. At the same time, the simple structure, high torque and power density, as well as the low cost of the switched reluctance machine (SRM) makes it a strong candidate for E-bikes. In this thesis, a 3-phase, external-rotor SRM with 6 stator poles and 10 rotor poles is designed for E-bike. The design of an external rotor arrangement of the 6-10 SRM topology has not previously been reported, hence it offers a new contribution to the published works. The machine design is initiated by the output power equation and is followed by a comprehensive finite element analysis (FEA). The external-rotor arrangement is chosen to facilitate ease of integration into the wheel hub structure of a typical pedal bicycle. The increasing rotor poles yield improved torque ripple reduction than more conventional (i.e. 6-4, 12-8 etc.) SRM design, which is an essential feature for low speed rider comfort. A new torque ripple reduction control scheme is investigated. Although the comparison shows that the torque sharing function has more positive result than angular position control with regards to torque ripple, this is at the expense of higher losses. Detailed thermal analysis ensures this machine is suitable to require no additional cooling system. The final machine design is experimentally tested via a full system prototype. Results highlight some limitation of the 2-D FEA in terms of the winding inductance calculation. Here, the end winding introduce more influence on short thickness machine, which will reduce its output power. However, its power-speed curve shows that this prototype machine has very strong overload ability., Master of Applied Science (MASc)

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