Finite-Time Adaptive Fuzzy Control for Three-Phase PWM Rectifiers With Improved Output Performance
Cheng Fu, Chenghui Zhang, Guanguan Zhang, Qijun Su
Abstract
For three-phase pulse width modulation (PWM) rectifiers, system uncertainties, such as load disturbances, parametric uncertainties, and grid disturbances, may result in significant DC-link voltage fluctuations, degrade the quality of grid currents, and even lead to system instability. To address this issue, a modified dynamic model of the PWM rectifier with system uncertainties is established, and a finite-time adaptive fuzzy control (FTAFC) method with the dual-loop structure is proposed. In the outer voltage loop, a finite-time adaptive law is used to maintain stable DC-link voltages despite load disturbances. In the inner power loop, an adaptive fuzzy technique is used to estimate and compensate system uncertainties, thus ensuring finite-time power tracking. It is confirmed that all signals of the closed-loop system are finite-time bounded. The experimental and simulation results demonstrate the effectiveness of the proposed method.