Synchronous-frame decoupling current regulators for induction motor control in highpower drive systems: Modelling and design

Abstract

In this study, a decoupling current regulator with a simple design approach aiming to mitigate cross-coupling effects during torque or speed disturbance is proposed for induction motor (IM) drives that operate at the low switching frequency. The proposed control method consists to derive a decoupling transfer matrix from the plant accurate model that is inserted at the output of the current controller, while traditional methods consider the feedback synchronous currents or their errors to calculate the compensation terms. The proposed method allows the controlled system to be equivalent to a dual single-input-singleoutput system without cross-coupling terms. The performances of this method have been validated through simulations and experiments on a 3-kW IM powered by a 3-level neutral-point clamped inverter at different operating conditions. The results show that the proposed decoupling approach provides additional bandwidth frequency than traditional approaches from literature. This characteristic translates into fast response time and improved decoupling dynamics at various operating conditions.