Research on Energy Efficiency System of New Energy Vehicle Electric Drive

Abstract

The motors of new energy vehicles adopt the built-in permanent magnet synchronous motor (PMSM) with high system efficiency. The mainstream control method of electric drive system is space vector PWM (SVPWM) algorithm. The SVPWM algorithm has higher low-order harmonic content in the low-speed segment voltage waveform, large asynchronous motor torque, and large motor iron loss, which makes the electric drive system less efficient in the low-speed segment system. This paper creatively proposes to change the modulation ratio M of the SVPWM waveform by adjusting the bus voltage, switching frequency and different control angles to reduce the harmonic content of the system to improve the overall efficiency of the electric drive system. In this paper, a theoretical model is established for the motor phase voltage harmonics, and various factors and components affecting the harmonic content are analyzed. Combined with the digital signal processor (DSP) based SVPWM vector control algorithm, the motor control SIMULINK simulation system is built. The voltage harmonic analysis of the simulation system is carried out by using the FFT tool in POWERGUI. The electric drive system bench is established for testing, the electric drive system simulation and the test bench test data are analyzed, and a clear method and means are proposed to reduce the harmonic content.