A three-phase AC power source using multivariable repetitive robust model reference adaptive control

This paper presents a computer-controlled three-phase AC power source for use in standard tests of electrical power devices. Developed with a multivariable repetitive robust model reference adaptive controller (MIMO RMRAC-RP), this scheme is able to generate sinusoidal waveforms with adjustable amplitudes and frequencies, as well as several arbitrary waveforms. Using αβ0 transformation and balanced three-phase load, the plant has its interactor matrix completely known, and in this case the multivariable control law may have its parameters reduced in number, reducing the computational effort to adapt them. For this MIMO RMRAC-RP with a reduced number of parameters, the augmented error equation is written, and the adaptation algorithm convergence mathematical proofs are developed, as well as the proof of the overall closed-loop system stability, despite the presence of unmodeled dynamics and bounded disturbances. Simulation and experimental results confirm good performance for linear and nonlinear three-phase loads.