Query: switched reluctance motor electric vehicles

title: Acoustic Noise Reduction of a High Efficiency Switched Reluctance Motor for Hybrid Electric Vehicles With Novel Current Waveform
abstract: One of the major topics of switched reluctance machines (SRMs) is how to reduce the acoustic noise and vibration without decreasing the efficiency. In this paper, a few novel current profiling methods are proposed to reduce the acoustic noise by flatting the radial force sum and to reduce optimal torque ripple with best efforts to enhance the efficiency. The proposed method is adopted to the 18/12 pole SRM, which has identical outer dimensions and competitive torque, output power, efficiency, and operating region of the permanent magnet motor used in the hybrid vehicles. It is found that the proposed method can improve not only the radial force ripple characteristic but also the iron loss minimization. The efficiency enhancement is also found to be possible in a few cases depending on the demanding criteria; thanks to the phase shift of the fundamental component of the current waveform. The proposed method is verified in the experiments.

title: Design and optimisation of an In wheel switched reluctance motor for electric vehicles
abstract: To improve the mechanical performance of the In wheel switched reluctance motor (SRM) used in electric vehicles (EVs) structure design and geometrical multi objective optimisation strategy for the In wheel SRM were developed in this study. The design method for major parameters of the In wheel SRM was presented by means of design specifications of the EVs. According to requirements of the EVs, four indicators of the SRM were defined to evaluate the development of the SRM and perform the optimisation. To simultaneously improve the static performance of the SRM, a novel multi objective simultaneous optimisation function was proposed by using four weighted factors and considering sensitivity analysis of the design variables on indicators. A four phase 16/20 In wheel SRM with an outer rotor was designed and optimised based on the proposed multi objective optimisation method. The influence of design variables on average torque, torque ripple, efficiency, and torque density was analysed based on a combination of finite element analysis and orthogonal experiment design method. The static and dynamic torque performances of the optimised SRM were evaluated and compared with those of the initial motor. The comparison results showed that the proposed multi objective simultaneous optimisation strategy can greatly improve the static and dynamic torque performances of the SRM.

title: An Asymmetric Three Level T Type Converter for Switched Reluctance Motor Drives in Hybrid Electric Vehicles
abstract: This paper introduces a 3 level converter for switched reluctance motor (SRM) drives for use in hybrid and electric vehicles. Current control by a 3 level converter can reduce torque ripple by about 40% compared to the standard asymmetric 2 level half bridge converter. The asymmetric neutral point clamped (NPC) converter is the preferred topology as a 3 level converter for SRM drives. This paper proposes an asymmetric T type converter which has improved efficiency, reliability and cost compared to the standard asymmetric NPC converter for low voltage applications like electric vehicles. The switching table and operating modes for the proposed converter are presented. Vehicle models in MATLAB/Simulink are used to quantify the system level converter performance compared to NPC for a standard city drive cycle.

title: Application of an in wheel direct drive motor based on switched reluctance motors for low power electric vehicles
abstract: This paper presents application of a switched reluctance motor with exterior rotor as an in wheel direct drive motor for low power electric vehicles (EVs) A prototype system is realized for experimental studies. Both analytical method and finite element analysis (FEA) are used in this research to obtain characteristics of the motor. The results of the FEA and analytical calculations are presented, and compared to experimental results. The obtained test and simulation results show that the proposed system is suitable for low power and low cost EVs.

title: Direct Instantaneous Torque Control of the Switched Reluctance Motor for Electric Vehicles Applications Using Fuzzy Logic Control
abstract: This paper presents direct torque control of Switched Reluctance Motor (SRM) using Fuzzy Logic Control (FLC) for electric vehicles applications. The PD FLC is proposed for SRM torque control, to keep the torque of the motor shaft in tracking the reference torque with high accuracy. With the help of FLC techniques, the SRM torque ripples can be reduced compared to traditional control techniques. In this study, the nonlinear 6/4 SRM model is simulated with the symmetrical converter, and the converter controller is programmed using C language. The proposed method is tested at different load and variable speed conditions, and the obtained results confirm that the FLC direct torque control can be used for torque control to improve the motor performance and reduce the torque ripples compared to other techniques such as direct instantaneous torque control.

title: Direct instantaneous torque control system for switched reluctance motor in electric vehicles
abstract: Switch reluctance motor is suitable for an electric vehicle driving system, which has the advantages of simple structure, high reliability of system and wide range of speed adjustment. In order to reduce the torque ripple of the system and improve the dynamic performance, a strategy of direct instantaneous torque control (DITC) based on a fractional order proportion integration differentiation (PID) controller is proposed. According to the mathematical characteristics of the fractional order controller, the form of the fractional order speed loop controller is determined. Also, the parameters of the speed regulator are designed using the frequency domain design theory of the control system. Then, the fractional order controller is discretised. Compared with the traditional proportion integration (PI) controller, the fractional order controller can have a better control effect. Simulation experimental results of the system show that the DITC control method has effectively reduced the torque ripple and the fractional integral controller has reduced the overshoot and adjustment time and improved the robustness and disturbance resistance of the system.

title: Switched reluctance motor design for electric vehicles based on harmonics and back EMF analysis
abstract: Permanent magnet synchronous motors are widely accepted in automotive applications. The high torque density, high rotational speed with maximum efficiency in electric vehicle applications is technically challenging for motor design. However, these machines are expensive and difficult to work at high temperature harsh environment due to permanent magnets demagnetisation features. Alternatively, switched reluctance motors can provide similar output characteristics and a wider speed. Thus these are considered to be more fault tolerant and more reliable. This study proposes a 20 kW, three phase switched reluctance motor and analyse its overall performance and harmonic contents. The study is conducted by optimising the slot filling factor, excitation voltage and switching sequence of an asymmetrical half bridge converter. A finite element model is used to predict the core and copper losses and other influencing parameters. Simulation results are presented and analysed the effectiveness of the proposed switched reluctance motor (SRM)

title: Multiobjective Optimization Design of a Switched Reluctance Motor for Low Speed Electric Vehicles With a Taguchi CSO Algorithm
abstract: 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.

title: An Integrated Switched Reluctance Motor Drive Topology With Voltage Boosting and On Board Charging Capabilities for Plug In Hybrid Electric Vehicles (PHEVs)
abstract: This paper presents a new topology of switched reluctance motor (SRM) drives for plug in hybrid electric vehicles. Six operating modes can be achieved as a result. Three of those modes are applied for driving and the others for charging. During the driving mode, the topology can be converted to a four level one. During the charging mode, two battery packs are charged in parallel with the boost circuit by the external ac source or generators. The main contributions of the proposed topology are as follows. First, a four level converter is formed by adopting different ways of connection (series or parallel) of the two battery packs (or the two capacitors) which can accelerate the excitation and demagnetization procedures of SRMs. Moreover, the topology contributes to decreasing the switching losses and extending the constant torque region to improve the drive performance as well. Second, the state of charge of the two battery packs (or the voltages of two capacitors) can keep balance on their own by parallel operation of the two battery packs. Furthermore, a detailed comparison between two drive modes of the proposed topology and asymmetric half bridge inverters is undertaken with simulation and experimental studies, the results of which demonstrate the validity of the proposed topology.

title: Iron Loss and Temperature Field Analysis of Four Phase 8/6 Structure Switched Reluctance Motor for Electric Vehicles
abstract: 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.