基于MTPA的永磁同步电机滑模变结构直接转矩控制

摘要

为解决传统控制方法中磁链和转矩脉动较大、低速性能较差等问题,将滑模变结构理论应用到永磁同步电机直接转矩的最大转矩电流比控制中.设计转矩的组合滑模面和磁链的积分滑模面,进一步提高变磁通控制时转矩的响应速度和稳态性能,减小磁链的脉动；分析离散域下高氏趋近律的缺陷,设计一种带内负衰减控制的趋近律用于转矩控制,在保证系统鲁棒性的前提下减弱了抖振.仿真结果表明,该方法具有动态响应快、转矩脉动小、在恒转矩区和弱磁区对电机参数变化具有强鲁棒性.%To solve problems associated with conventional direct torque control(DTC) of permanent magnet synchronous motor (PMSM) based on the strategy of maximum torque per ampere (MTPA) , such as flux and torque ripple, difficulty to accurately control at low speed, a variable structure sliding mode (VSS) control strategy is proposed. A slide-mode was designed to improve the speed of response and steady - state performance of torque and to reduce the flux ripple. To reduce the chattering and maintain the robustness, an improved exponent reaching law was applied to control the torque. Simulation results show that the control strategy solves these problems effectively and shows strong robustness to parameters variability in both constant torque and field weakening control.