Research On Switched Reluctance Motor-Based Drive Systems For Light Weight Type Pure Electric Vehicles

In the new century, energy shortage and environmental pollution are very important issues facing mankind, and they are currently the hot focuses with conderable attentions. Hence, the energy-saving and environment-protecting new-energy vehicles in this context come into being, among which the pure electric vehicle has a rapid growth due to its unique advantages in operating process, such as zero emission, no pollution, and high efficiency.On the other hand, switched reluctance motor (SRM) has a simple structure, high reliability, wide speed range, large starting torque, and many other merits. Due to its excellent inherent advantages, SRM is also developing rapidly and it has been widely applied in the aerospace, textile machinery, oil exploitation, electric cars and other fields. This thesis aims to analysis, design and manufacture a three-phase 4kW SRM drive system for the low voltage pure electric vehicles, based on the comprehensive research on conventional SRMs.The main research contents of this thesis are as follows:(1) The operation principles and control strategies of SRMs are introduced briefly. The current formation of the electric circuits and the internal electromagnetic fields when the machine work as a motor or a generator is analyzed in detail.(2) The structure features and a mathematical model of a 3-phase 4kW SRM with 12 stator slots and 8 rotor poles are analyzed and established. Key related design parameters and measured static characteristics of this SRM prototype are given. Then, a magnetic field-electric circuit co-simulation model of the SRM is built based on the software of Ansoft/Simplorer to combine finite element analysis (FEA) and complicated control arithmetic. Finally, a comprehensive comparison of electromagnetic performance under different control arithmetics is conducted.(3) The hardware circuits of the SRM controller are designed and implemented. After analyzing the principle and structure of each circuit, a frasible circuit model is selected. The circuit boards are manufactured and tested.(4) The software of the SRM controller is designed and implemented. A microprocessor based on the core of ARM Cortex-M3 is used to accomplish the acquisition and conversion of signals, and the calculations of data and the implementation of control algorithm are performed through the cooperation with circuit modules. Finally, a C program is developed for the software of RVMDK.(5) On the basis of the completed work of software and hardware, an experimental platform is set up to put experiments of SRM drive system into effect. The features of SRM drive system using different control algorithms are compared, and the efficiency of motor, controller and the drive system are measured respectively. The performances of SRM drive system are fully evaluated to establish a theoretical and experimental basis for the futher practical application of SRM in electric vehicles.