Three Phase Control for Pwm-switched Autotransformer Voltage-sag Compensator Based on Phase Angle Analysis

Enhancing compensating capability is essential in a voltage-sag compensator. It involves two main aspects, first, sag detection technique and second, voltage sag compensator. Many detection techniques have been introduced to measure and to detect voltage sag, such as RMSValue Evaluation and Peak-Value Evaluation. Unfortunately, most of the techniques require a delay for sag to be detected then compensated, whereas immediate sag detection is vital to improvement of transient performance. Presented is a three-phase PWM-switched autotransformer voltage-sag compensator that is based on AC-AC converter and that uses the proposed three phase controller based on Phase Angle Analysis as the detection technique. The significant advantage of this detection technique is the detection time. It is capable of detecting and compensating voltage sag the moment sag occurs without delay. Its effectiveness and capability were verified via MATLAB/Simulink simulation.