A Novel Current Control System for PMSM Considering Effects from Inverter in Overmodulation Range

In this paper, we propose a novel current control system for PMSM when an inverter operates in the overmodulation range. Because of the effect from harmonic components generated from an inverter in this range, an unstable problem in current control system will occur. For solving this problem, the method of harmonic currents compensation is proposed. However, the difficulty in this method is that how much we can estimate harmonic current accurately. There are two new topics in harmonic components estimation those we use in our proposed current control system. First, the harmonic voltages estimation method based on the conventional Sine-PWM modulation method of an inverter. Second, the harmonic currents estimation method that not consider only a model of PMSM, but also an effect from current controllers. The effectiveness of our proposed system is confirmed by computer simulation and experimental results.