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Based on a four-phase 8/6 structure switched reluctance machine for electric vehicles, the influence of different magnetic pole distributions on iron loss and temperature field is studied here. Firstly, by fitting the core silicon sheet iron loss data of the prototype, a mathematical calculation model of switched reluctance iron loss is constructed. Then, in order to analyse the flux density waveform of the iron core, a 2D finite element model is proposed. Under different magnetic pole distributions, the magnetic flux densities of the iron core are compared and the iron loss is calculated as well. Finally, the simulation results are obtained by establishing the 2D finite element thermal model of the prototype and analysed. Then, the experimental test platform is built and experimental data are recorded and analysed. By comparing the experimental results, it is found that the temperature rise is well consistent with the temperature rise of the 2D finite element thermal model.

In this study, the design optimisation of a switched reluctance machine (SRM) with the layered method has been studied. Firstly, a multi-physical analytical model for the SRM is established. The proposed model consists of an electromagnetic model, an electrical model, a loss model, and a thermal model. Then a layered optimisation design method suitable for the SRM is proposed in combination with the multi-physical field simulation model. Taguchi method is used to analyse the influence degree of the main geometric dimensions on the dynamic performance, and the parameters are divided into high-sensitivity parameters (HSPs) and low-sensitivity parameters. The non-dominated sorting genetic algorithm-II algorithm is used to optimise the HSP by the proposed model. The iron loss, average torque, average torque per unit mass, torque ripple and efficiency are taken as the objective functions. Finally, the prototype is manufactured and a testing platform is built. The flux linkage of several special positions of the machine is verified experimentally, and the accuracy of the electromagnetic model in the multi-physical field model is verified. The temperature experiments are carried out on the machine, and the accuracy of the equivalent heat circuit model in the multi-physical field model is verified.

Purpose An improved simulation model of switched reluctance motor (SRM) for steady-state operation that considers the core losses in the stator and rotor is established to obtain the steady performance of the high-speed SRM during the design, analysis and control of SRM driving system more accurately. Design/methodology/approach The transient core loss model for the material and SRM is presented. Then a new method for calculating the flux density of the motor in real time is introduced, and a steady-state simulation model of the SRM including real-time transient core losses calculation model is established according to the transient flux density. Because the transient core losses calculated by above method are the total core losses of the motor, a core losses distribution method is proposed and the steady-state simulation model of the SRM including the distributed core losses’ effect on the phase winding is established. Findings The comparison results show that the proposed model has higher accuracy than the traditional model, excluding core losses, especially at the moments when phase voltage is turn-on and turn-off. The proportion of the core losses to the motor losses increases with the increase in speed. So, the core losses’ effect on the steady-state performance of the high-speed SRM cannot be ignored. Originality/value The method to obtain flux density in the real time is presented and the improved steady-state simulation model of SRM that considering transient core losses is proposed.

This paper analyzes the flux characteristics and normal force of the double-sided switched reluctance linear machine (SRLM) under the asymmetric air gap. The magnetic equivalent circuit (MEC) of the machine and the details of the flux paths configuration at six distinct mover positions under the asymmetric air gap are included. Then, six special mover position magnetization curves are calculated by solving the MEC with the method of Gauss–Seidel. The magnetic flux-linkage model and thrust model based on six distinct mover positions are established by analytical polynomial. Three-dimensional (3-D) finite-element method (FEM) simulation and the experimental study with the prototype hardware are carried out to validate the accuracy of the MEC model calculated for the flux linkage and normal force. The six distinct mover positions flux linkage and normal force calculated by the MEC are consistent with the 3-D FEM calculated data and experimental data. It indicates that the proposed method to calculate the flux linkage and the normal force is feasible and effective. The dynamic analysis is also conducted. The simulated phase current waveforms are also consistent with the experimental results. It indicates that the presented method can be used to simulate the phase current under the asymmetry air gap effectively. The normal force under different asymmetry rates is analyzed, which provides the theoretical basis for reducing the unbalanced force of the double-sided SRLM.

In this paper, a novel double stator switched reluctance machine (DSSRM) is proposed, which combines the characteristics of the magnetic circuit of the U-type stator modular switched reluctance machine (SRM). By optimizing the polarity distribution of the motor, the magnetic field produced by the inner and outer stator windings can be decoupled, so that the inner and outer stator windings can be controlled separately. On this basis, it is proposed that the center line of the inner and outer teeth of the rotor be staggered at a certain mechanical angle. To optimize the mechanical angle of the motor and reduce the torque ripple of the motor.

This paper proposes a novel multiobjective optimization design method for a switched reluctance motor (SRM) on low-speed electric vehicles (EVs). According to the indexes of a low-speed EVs propulsion system and the large torque ripple of the SRM, six objectives of geometric parameters optimization of the SRM are given, which are maximum speed, acceleration time (including in situ acceleration time and overtake acceleration time), maximum climbing gradient, energy usage ratio, and torque ripple factor. The rated parameters of the driving motor are given based on the basic parameters of the low-speed EVs. Based on the engineering design method, the dimension range of the SRM under the rated parameter range is confirmed. The dynamic simulation model of a low-speed pure EVs propulsion system is built in MATLAB/Simulink based on the finite element model of the SRM and the vehicle balance equation. Then, a multiobjective optimization design of the geometric parameters of the SRM is carried out by a Taguchi–chicken swarm optimization algorithm. The correctness of the finite element model is verified, and the accuracy of the multiobjective optimization is verified by the dynamic simulation results and the low-speed EV experiment.

This study sets forth an equivalent electric circuit (EEC) model including core losses and phase interactions to obtain a more accurate steady and dynamic performance of the high speed switched reluctance motor (SRM) during the design, analysis, and control of the SRM drive system. The magnetic equivalent circuit (MEC) method is used to calculate the flux linkage and torque quickly and relative accurately. Based on the principle of transformation between the MEC and EEC, the EEC model is derived from the MEC model. To enhance the model precision, the dynamic core losses and phase interactions are analysed and added to the EEC model. The relationship between the phase current and virtual current corresponding to different parts is deduced. Then the simulation model of the whole SRM driver systems is established in MATLAB/Simulink to obtain the phase current and virtual current corresponding to a different portion. The experimental and simulated results of the static MEC model and the whole SRM drive system including the EEC model provide the conclusive evidence for validating their practicability.

This paper introduces a novel 16/12 outer module rotor-type switched reluctance machine. Unlike conventional structures, the proposed rotor structure includes some discrete module, and every outer module rotor is U-shaped structure and has two rotor poles. Each phase winding is composed of two series coils wrapped on two stator teeth. The short flux lines can be generated by excited adjacent phase and use the U-shaped module rotor. The module rotor can also decrease the mass of the rotor. The proposed U-shaped structure machine can enhance the electrical utilization, decrease the magneto motive force requirement, and reduce the iron loss compared with the conventional machine. The operation and design principle of the proposed U-shaped structure machine are illustrated and elaborated to verify the machine operation performance. The static and dynamic performance of the proposed U-shaped structure 16/12 outer rotor machine and conventional machine is obtained by the finite-element method. The effectiveness and availability of the proposed U-shaped structure outer rotor machine are confirmed by the simulation results.

Purpose This paper aims to establish a modified variable coefficient calculation model to analyse the control parameter effect on the iron loss of switched reluctance motor under pulse width modulation (PWM) mode. Design/methodology/approach The finite element model is solved to get the flux density by python language. Due to non-sinusoidal flux density feature and the effect of PWM excitation, the Fourier transform is applied in consideration of harmonic components. To improve the accuracy of iron loss computation, the effect of minor loops is considered by using the rain-flow counting method. Findings When the speed fluctuates around the set speed and the fluctuations are relatively small, it is useful to reduce the iron loss with smaller duty ratio and turn-on angle or greater duty ratio and smaller turn-off angle. The iron loss is less affected by chopping frequency, while the iron loss increases obviously with higher conduction angles. The iron loss under non-energy-returnable-voltage-chop mode is greater than energy-returnable-voltage-chop mode. Originality/value The modified variable coefficient MIEM5 iron loss model is proposed to improve the accuracy of iron loss calculation. Then the control parameters such as duty ratio, chopping frequency, turn on angle and turn off angle are analysed under PWM mode.

Tubular switched reluctance linear motor (TSRLM) has lower loss and higher thrust density than flat-type switched reluctance linear motor. Two kinds of single-phase TSRLMs with different surrounding magnetic flux paths are introduced in this paper. The structure of transverse flux TSRLM (TF-TSRLM) is compared with the structure of the longitudinal flux TSRLM (LF-TSRLM). The structure selection of TF-TSRLM with two poles, four poles, six poles, and eight poles is made for enhancing average electromagnetic thrust. The comparisons between LF-TSRLM and TF-TSRLM are made in the same stator outer diameter, the same mover laminated thickness, and the same excited current on static electromagnetic thrust, magnetization curves, average thrust per unit volume, and average thrust per unit mass. They show that the TF-TSRLM with the six-pole structure is considered as a relatively more reasonable structure for enhancing the space effective utilization rate and increasing the electromagnetic thrust.

This study analyses the influence of the control parameters on the iron loss of the switched reluctance motor under different control modes by using the motor iron loss model which is suitable for different control modes. The motor iron loss model combines the magnetic equivalent circuit (MEC) method with the finite element (FE) method. First, the static flux density of the motor is obtained by the FE software, and then the relationship between the characteristics of static flux density and dynamic flux density is analysed through the MEC method. In combination with the motor dynamic MATLAB/Simulink model, the dynamic flux density of different feature regions is obtained. Simultaneously, the iron loss model of the motor is established in MATLAB/Simulink according to the loss model so that the motor loss can be calculated rapidly and accurately. Then, the influence of the control parameters on the motor loss is calculated and analysed under angle position control and current chopping control. The accuracy of the loss model and analysis results are verified by experiments.

This paper studies about the influence of different polarity distribution on the iron loss and temperature field on a four-phase 8/6 structure switched reluctance machine for electric vehicles. Firstly, a switched reluctance iron loss mathematical calculation model is proposed by fitting the core silicon sheet iron loss data of the prototype. Then, a 2D finite element model is constructed to analyze the magnetic flux density waveforms of iron core. Magnetic flux densities of the iron core under two different magnetic poles distributions are also compared. The iron loss of the different magnetic pole distribution is calculated respectively. Finally, the 2D finite element thermal model of the prototype is established and the simulation results are analyzed. Then, the experimental test platform is built. The experimental results show that the temperature rise is in good agreement with the simulated temperature rise.