Research Of Switched Reluctance Machine Controller For Hybrid Electric Vehicle

Many developed countries today face the challenges of energy shortage and environmental problems in the continuant development of traditional automotive industry. . Electric vehicle (EV) can realize the localization of energy source and it is the ultimate choice of zero-discharge, energy-saving, and environment-friendly automobile. However, the behavior of the power cell restricts the application and development of electric vehicle. Since the 21st century, various automobile manufacturers start to focus make emphasis on the research and development of hybrid electric vehicle, which is practical and easy to industrialize in short period of time. Our government recognized the situation and has made electric vehicle research one of the top science and technology priorities in the "10th five-year"period. Hybrid electric vehicle (HEV) is one of the main research and development focus. Electric machine and controller are key parts of HEV. There are various types of electric machines for hybrid electric vehicle, among which the switched reluctance drive (SRD) becomes the preferred method with its simplicity, substantial structure, and outstanding performance. This dissertation carries out monographic study of key technologies of SRD for HEV based on the National "10th five-year""863"Electric Automobile Graveness special topic. The outcome of this study proves to be very satisfactory by applying it to HEV in production. The full context is divided into six parts: Firstly, it discusses the history of electric vehicle and up to date development. It then introduces basic structure of hybrid electric vehicle and the variety of electric machines suitable for electric machine along with their characteristics. It particularly addresses the latest advance of switched reluctance drive and its merits and demerits for electric vehicle. Finally it describes the background of the project. On the basis of dynamic performance indexes of vehicle traction,the requirement of universal characteristic in the traction system is derived. It is proved that extensive constant power bound is necessary for electric drive system. At the same time, the design philosophy of electric drive system for EV is clearly illustrated. According to the specification of entire car design and universal characteristics of Cummuis ISBe 150 engine, technical requirements of electric machine and controller for hybrid electric bus are derived. In order to analyze different kinds of control strategies for EV with SR machine thoroughly, dynamic simulation model of SR machine is established. It is emphasized on the impact analysis of inductance characteristic for electric machine. HEV demonstrates higher requirements for electric machine. The electromagnetic design of electric machine should satisfy its performance indexes. Moreover, the difficulty of execution and developmental level of power device at present must be taken into account in order to get the best cost / benefit for the system. SRD is a representative electromechanical integration system. Excellent electric machine can not achieve optimal performance without advanced control strategies. Chapter four in this dissertation describes in details the interior electric structure and external interfaces of the controller for a car. It introduces control strategies for torque, speed, current and angle, and presents a brand-new current chop mode. It is well-known that the control of power generation in SR machine is difficult all the time. It is illustrated clearly that performance of power generation and electro motion will be absolutely symmetric provided that the control strategy is appropriate in accordance with the equation of balance of voltage and inductance characteristics. Moreover, the mechanisms of production of out-of-control current and relevant preventative countermeasures are analyzed in power generation control of SR machine. Excellent controller must have favorable electromagnetic compatibility. The dissertation presents the overall process of EMC design of the SR machine controller for HEV in detail. The noise of SR machine relates to electric machine design, construction design, control strategy and fixing mode of electric machine. By synthesizing manifold schemes, the system obtains preferable effect and users'satisfaction. Because of the high torque ripple characteristic of SR machine, the dissertation explores the direct torque control strategy of SR machine and conducts simulation analysis. The effect of the control strategy is also verified in a low-power machine.