Optimizing three phase current regulators for low inductance loads

In this paper, a new space vector based predictive current regulator is proposed which is suitable for operation with low inductance loads such as high speed motor drives with low inductances particularly for electric vehicle applications, high dynamic response servo and vector controlled motor drives, voltage source inverters-VSIs-connected to utility grids and interconnected UPS systems with active damping requirements, and for nonsinusoidal current tracking applications such as for active filters. The proposed predictive current regulator achieves: constant switching frequency by using a carrier based space vector voltage PWM switching strategy, minimizes both high and low frequency current errors and can operate with extremely low load inductances of typically <5%. This implies that good spectral performance and spectral separation is maintained at light loads and enables the proposed current regulator to achieve insensitivity to load inductance. The paper presents a new analog modulator implementation and includes a simulated and experimental validation of the proposed predictive current regulator for sinusoidal and nonsinusoidal current tracking with low inductance loads.