A Robust Adaptive PI Voltage Controller to Eliminate Impact of Disturbances and Distorted Model Parameters for 3-Phase CVCF Inverters

This paper presents a robust adaptive PI voltage controller (PIVC) that effectively eliminates the impact of disturbances and distorted model parameters for a three-phase constant voltage constant frequency (CVCF) inverter with an output LC filter. The proposed controller contains an adaptive control stage to enhance its tracking performance by compensating for distorted model parameters and a feedback control stage to stabilize the error dynamics to converge to zero. Unlike a conventional PIVC, the proposed adaptive method automatically updates its gains using the adaptive control stage. The stability of the proposed controller is proven by the Lyapunov stability theory. Even without information regarding the load current, the proposed adaptive PIVC achieves a fast dynamic response, small steady-state error, and low total harmonic distortion under critical load conditions. Experimental results demonstrate the efficacy of the proposed control method on a prototype three-phase CVCF inverter using a TI TMS320F28335 DSP.