The most known SVC are the DVR TM (Dynamic Voltage Re-storer) and DySC TM (Dynamic Sag Corrector), which are used to protect sensitive loads. The voltage injected by the DVR is sinusoidal, produced by an H-bridge inverter which is modulated using Pulse Width Modulation (PWM) and a sinusoidal output filter. Considering that voltage sags are fast phenomena that usually last hundreds of milliseconds, this paper proposes the use of square-wave voltages to compensate sags as well as the control strategy for the compensator. Experimental results show the effectiveness of the injection of a square-wave voltage for the protection of electronic loads.
sag; series voltage compensator; power quality