Maximum Torque Per Ampere Control For Interior Permanent Magnet Synchronous Motors Based On Signal Injection Method

The built-in permanent magnet synchronous motor(IPMSM)is often used as a motor for electric vehicles because of its high working efficiency and high power density.And because the permanent magnet is a built-in special placement structure,it will generate extra reluctance torque in addition to the conventional electromagnetic torque.In order to maximize the use of this advantage,the maximum torque-to-current ratio(MTPA)control is often used to enhance the built-in type Permanent magnet synchronous motor torque output capacity,or to obtain higher efficiency.However,the rated parameters of the on-board motor under such complex working conditions vary with the influence of temperature and magnetic field during operation.As a result,it is difficult to provide the correct and optimal MTPA angle based on the formula method MTPA control.Therefore,parameter-independent MTPA control based on auxiliary signal injection has become a hot research direction in recent years.However,the dynamic performance of this type of algorithm is poor,so with this as the solution goal,in-depth research and improvement are made for the MTPA control based on auxiliary signal injection.Firstly,the basic principle of MTPA control based on formula method is explained.Secondly,two kinds of MTPA control injected(real sine signal and virtual sine signal)are analyzed and researched.It is found that the common problem in the sine signal injection method is:The identification signal containing the target MTPA angle is extracted from complex signals such as torque,so band-pass filters and low-pass filters are usually used together.Therefore,the dynamic response of the system is poor and requires complex filter and controller design.Therefore,this paper proposes a signal extraction algorithm without using a band-pass filter by improving the method of signal extraction calculation.The actual sine signal injection method and the virtual sine signal injection method are respectively compared before and after the improved algorithm.Simulation results show that the correctness,effectiveness and robustness of the proposed improved algorithm against parameter mismatch.