Adaptive fuzzy control for uninterruptible power supply with three-phase PWM inverter

The major problems of uninterruptible power supply (UPS) with three phase PWM inverter arise from unknown nonlinear loading to and phase couplings of the inverters. In this paper, an adaptive fuzzy control is proposed to solve these problems. The control objective is to track the desired sine waveform regardless of the versatile nonlinear loading, whose bound can be represented by a fuzzy rule-base. The algorithm embedded in the proposed architecture can automatically update the fuzzy control rules and, consequently, drive the tracking errors to a designated neighborhood of zero.