Weighting Factor Free Lyapunov-Function-Based Model Predictive Control Strategy for Single-Phase T-Type Rectifiers

Abstract

This paper presents a weighting factor free Lyapunov-function-based model predictive control (MPC) for single-phase T-type rectifiers. The stability of the rectifier can be guaranteed if the derivative of Lyapunov function is negative. Motivated from this fact, the design of cost function (Lyapunov function) is based on stability of the rectifier. Since the coefficient used in the formulation of the Lyapunov function does not have any effect on the performance, the cost function becomes weighting factor free. The weighting factor free based MPC brings simplicity in the practical implementation. The performance of the proposed control technique has been investigated under normal and distorted grid voltage conditions during steady-state and transients caused by the load change. In all cases, the output and capacitor voltages are regulated at desired voltage levels, grid current tracks its reference and achieves unity power factor operation.