Research On Control Strategy Of High Performance IPMSM Drive For Electric Vehicle

The rapid development of automotive industry has greatly promoted thedevelopment of the society and economy. While bringing benefits to humanbeings, cars have also caused some problems. The petroleum is non-renewableenergy, with the petroleum consumption rapidly rising, we are facing a hugeenergy crisis. In addition, the air pollution caused by automobile exhaust hasbeen getting more and more serious. Under this background, the energy-savingelectric vehicle has become an inevitable trend.The motor drive system is the power unit of an electric vehicle. theperformance of the motor drive system have great influence on performance ofelectric vehicle. In this paper, the Interior Permanent Magnet Synchronous Motor(IPMSM) drive system has been studied, In order to improve the performance ofthe motor drive system, plenty of work has been done on choosing the rightcontrol strategy, determining the parameters and characteristics of IPMSM, andraising the output torque in the constant power region.Firstly, this paper has discussed kinds of vector control strategies based onrotor flux orientation, took into account the characteristics of the IPMSM andelectric vehicle motor drive system, the maximum torque per ampere controlmethod and the negative idfeedback flux weakening control method has beenselected as the main control strategy. In order to reduce the torque output error inthe flux weakening region, an optimization algorithm has been added to thenegative idfeedback flux weakening control method. Secondly, with off-lineidentification, the paper has gotten the motor parameters such as armaturewinding resistance, flux linkage constant, and direct and quadrature axisinductances for the control. Then, this paper has discussed advantages anddisadvantages of variable voltage system and overmodulation technique, both ofthem can improve the output of the inverter. To meet the real situation, theSVPWM overmodulation technique has been used to improve the torque outputin the constant power region. At last, in order to reduce the fluctuations incurrent control loop in the overmodulation region, an optimization algorithm hasbeen proposed.