To solve the problem that in dynamic process of sudden change of PMSM load torque,the fluc-tuation of super-twisting sliding-mode observer(STSMO)rotor electric angle estimation error is intense e-ven under the regulation of angle compensation method based on PI regulator,the mathematical model of PMSM rotor electric angle compensation method was established according to the definition of angle esti-mation error,and the variable-step close-loop angle compensation method using tangent reaching law was proposed from the perspective of sliding-mode control and reaching law theory.The tangent value of half angle estimation error was chosen as angle regulating step of compensation method and was calculated by sine and cosine signal of angle estimation error obtained by feedforward decoupling algorithm,which can improve the dynamic performance as well as ability against disturbance of PMSM sensorless control sys-tem.According to the definition of normalized sensitivity,the method of system dynamic performance a-nalysis based on normalized compensation sensitivity was proposed by analyzing the sensitivity of regula-ting step to the variation of angle estimation error,which can compare the dynamic performance of the system under the regulation of 2 different compensation methods.Calculation and simulation results show that the normalized compensation sensitivity of tangent method is higher than that of PI method.This means that the tangent method can achieve better compensation accuracy and suppress the fluctuation of angle estimation error when angle estimation error changes dramatically.Finally,relevant experiments have been conducted,whose results show that for experimental PMSM,tangent method can reduce the fluctuation of angle estimation error by 61.9%and shorten the transient process by 23%in dynamic process of sudden increasement of rated load torque.The dynamic performance and ability against dis-turbance are improved effectively.
维普
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