Research On BLDCM And Its Drive System Used In Electric Bus

Firstly the status of EV investigation and development is introduced in this thesis, and the primary targets of research on traction system of electric bus are established. On the basis of this, the main works achieved in this paper are as follows:(1) The general block diagram of traction system used in electric bus is designed, then, the functions and their relationship of the main assembling parts are presented briefly. According to the chassis parameters of LIBRATE CA6120D100 bus, traction powers under several typical working conditions are calculated, which the power (120kW) choosing of motor can be according as.(2) The characteristics of several kinds of traction motor used in electric vehicle are analyzed and compared, and at last, Brushless DC motor (BLDCM) is adopted to be the traction motor, and the design and calculation about main dimensions and electromagnetic parameters of 60kW BLDCM is achieved in this thesis.(3) According to the conclusion of traction motor design, the research about control system is the main content, which include the design of main circuit, control structure, control centre (computer), then, according to usual status electrical bus worked in, the strategies that can achieve the function of electronic differential and regenerative braking are advanced, and the effects achieved by the advanced control strategies are calculated.(4) A simulation model of BLDCM and its drive system are established, which can be proved exact by the open loop experiment, and on the basis of this, a simulation experiment is operated to find how to restrain commutation torque ripple.