Nonlinear Synergetic Control of Circulating Currents in Parallel Three-Phase Inverters for Power Induction Motor Drive

This paper introduces an innovative methodology for designing a synergetic controller (SYC) aimed at eliminating circulating currents and regulating speed in two parallel-connected three-phase voltage source inverters used for powering induction motor (IM) drives. The control strategy is based on the indirect field-oriented control (IFOC) technique applied to the IM. A significant challenge of the parallel inverter structure lies in the generation of circulating currents between the two inverters. The proposed synergetic control approach effectively mitigates this issue while enhancing speed regulation. Key advantages of this method include a reduced system order, the independent control of variables such as speed and torque, excellent stability and dynamic performance, and robustness against parameter variations. Simulation results highlight the superior stability, performance efficiency, and dynamic behavior of the synergetic controller when compared to the conventional proportional-integral (PI) controller.