死区效应对定子磁链观测的影响与抑制研究

Study on the Influence and Inhibition of Dead-Time Effect on Stator Flux Linkage Observation

针对永磁同步电机基于空间矢量调制的直接转矩控制系统中定子磁链观测的问题,研究了一种考虑逆变器死区效应的定子磁链观测器。采用一种截止频率可调的低通滤波器代替积分器计算定子磁链,并考虑了逆变器死区效应对定子磁链观测的影响,对由逆变器死区效应引起的定子磁链观测误差进行了补偿策略分析。仿真和实验验证了该定子磁链观测器的有效性。实验结果表明,该方法能够消除积分型定子磁链观测器的积分初值、积分漂移和直流偏置的影响,能消除逆变器死区效应引起的磁链观测误差,提高定子磁链观测的准确度。

Aiming at the problem of stator flux linkage observation in the direct torque control system based on space vector modulation (SVM-DTC) of permanent magnet synchronous motor (PMSM),a stator flux linkage observer considering the dead-time effect of inverter was studied.The stator flux linkage observer used a low-pass filter (LPF) with adjustable cut-off frequency instead of the integrator to calculate the stator flux linkage,meanwhile the influence of the inverter dead-time effect was considered.The compensation strategy of stator flux linkage observation error caused by inverter dead time-effect was analyzed.Simulations and experiments results verified the effectiveness of the stator flux linkage observer.The experimental results show that the introduced method can eliminate the influence of the integral initial value,integral drift and DC offset of the integral stator flux observer,and can eliminate the flux linkage observation error caused by the inverter dead-time effect and improve the accuracy of the stator flux linkage observation.