DPWMMIN调制方法的损耗分析及其非线性电压误差补偿策略

不连续PWM调制与传统空间矢量调制相比能够降低开关次数与损耗,提高变换效率.然而,死区效应、管压降会引起感应电机的相电压非线性误差,导致定子电流谐波畸变增加,转子磁链观测精度降低,且传统的基于占空比的补偿方法并不适用于不连续PWM调制.针对不连续最小值调制策略(DPWMMIN)的损耗与电压误差展开研究,首先对导通损耗与...

Loss analysis and nonlinear voltage error compensation strategy of DPWMMIN modulation method

Compared with traditional space vector modulation, discontinuous PWM modulation can reduce switching times and losses and improve conversion efficiency. However, the dead-time effect and tube volage drop can cause phase voltage errors in the induction motor, increase harmonic distortion of stator current, reduce accuracy of rotor flux observer, and the traditional voltage error compensation method based on duty cycle is not suitable for discontinuous PWM modulation. In this paper, the loss and voltage error of DPWMMIN are studied. First, the conduction loss and switching loss are analyzed and calculated, and then the three phase-voltage of different sectors is deduced taking into account switching delay, dead time and tube voltage drop. The voltage error is deduced. From this an average voltage feedforward compensation strategy for DPWMMIN modulation is proposed. Finally, the simulation and experimental results show that the compensation strategy can effectively reduce the torque ripple and harmonic distortion of stator current and voltage, and increase the accuracy of the rotor flux observer. This proves the feasibility and correctness of the theoretical analysis and compensation strategy. This work is supported by the National Natural Science Foundation of China (No. 51507055).