Research On Dual Inverter Topology And Control Strategy Of Electric Vehicle Drive System

The power electronic devices in the inverter are the most vulnerable to failures in electric vehicle motor drive system. Open-end winding motor drive system is a new system topology in which each side of the opened windings is connected to an inverter, realizing the formation of double-ended power supply. With flexible power supply mode selection, fault tolerance, diverse voltage vector modulation and other characteristics, open-end winding drive system is used widely in electric vehicle. Meanwhile, considering such features as large power density, high efficiency, small size, simple control of permanent magnet synchronous motor(PMSM), dual inverter open-end winding motor system of electric vehicle is combined with PMSM, and its topologies and control strategies are studied in this paper as follows.Firstly, the research background of electric vehicle open-end winding motor drive system is summarized. Then, the current research on such topics as the topologies, voltage vector modulation strategies of dual inverter, the control methods of open-end winding motor system as well as the general control strategies of PMSM system from home and abroad are reviewed and analyzed.Secondly, the mathematical model of open-end winding PMSM is presented. Furthermore, the common mode voltage of dual inverter open-end winding motor system with single power supply is described and analyzed.Thirdly, a new SVPWM of dual inverter open-end winding motor system with none common mode voltage space vectors is proposed. And in fault conditions,common mode voltage suppression strategy with valid voltage space vectors constructing zero vectors is introduced. Also, the vector control method of open-end winding PMSM system is described.Lastly, the simulation model of dual inverter open-end winding PMSM control system with common mode voltage suppression SVPWM and vector control method is set up in Matlab/Simulink. Meanwhile, the experiment has been carried out to prove the correctness of the proposed topology and control strategy.