MTPA Control Method Of Permanent Magnet Synchronous Motor Based On Random High Frequency Sinusoidal Injection

Permanent Magnet Synchronous Motor(PMSM)is widely used in various industrial fields due to its high power density and high efficiency.Interior Permanent Magnet Synchronous Motor(IPMSM)produces reluctance torque due to its special rotor structure.The control method of Maximum Torque per Ampere(MTPA)can improve the utilization rate of reluctance torque,and then improve the motor load capacity and system efficiency.In the actual operation process of IPMSM,its inductance parameters will change due to the influence of magnetic circuit saturation and cross-coupling effect,which will affect the effect of MTPA control.In this paper,based on the mathematical model of the motor considering the saturation of the magnetic circuit and the cross-coupling effect,the MTPA control method based on high-frequency sinusoidal signal injection is studied.Aiming at the noise problem generated by the traditional fixed-frequency signal injection MTPA control method,a MTPA control method based on random high-frequency sinusoidal injection is proposed.Finally,the proposed control method is verified by simulation experiments.Firstly,the mathematical model of IPMSM considering magnetic saturation and cross-coupling effect is established.Based on this,a high-frequency signal injection MTPA control method considering magnetic saturation and cross-coupling effect is proposed.This method simultaneously injects highfrequency sinusoidal signals in the d and q axes,extracts the relevant components of the MTPA criterion in the mechanical power response of the motor,and controls them to be equal to zero to obtain the optimal current vector angle.According to the given stator current amplitude,the given values of the quadrature and direct axis currents are calculated,and then the MTPA control is realized.Secondly,the traditional high-frequency signal injection MTPA method,because the frequency of the injected signal is a fixed frequency,through the analysis of the IPMSM phase current power spectral density,it can be seen that the spike generated at the frequency of the injected signal brings sharp noise.Therefore,this paper improves the existing problems by injecting random high-frequency sinusoidal signals,and uses power spectral density to analyze the noise reduction mechanism of random sinusoidal injection method,and gives the selection conditions of random sinusoidal signal frequency and amplitude.The proposed control method is modeled and simulated in MATLAB/Simulink.The proposed highfrequency sinusoidal signal injection MTPA control method can significantly reduce the stator current amplitude compared with the traditional method,and has faster dynamic performance and more accurate MTPA trajectory tracking effect.At the same time,the control accuracy of the MTPA control method based on random high-frequency sinusoidal signal injection is also improved compared with the traditional method.The peak value in the phase current FFT analysis and PSD analysis is eliminated,and the noise reduction effect is good.The feasibility and effectiveness of the MTPA control method based on random high-frequency sinusoidal signal injection are proved.