Automatic voltage regulator based on series voltage compensation with ac chopper

This study proposes an automatic voltage regulator (AVR) based on series voltage compensation with an ac chopper. The proposed AVR is made up of a pulse-width-modulated (PWM) ac chopper and a transformer for series voltage compensation. In the ac chopper, the commutation problem is solved by switching patterns. The ac chopper provides direct ac–ac power conversion without energy storage elements, so the size and cost of the AVR are reduced. The ac chopper compensates for only the required voltage, so the switches have reduced ratings and stresses. Using bypass switches, the proposed AVR can compensate not only for the voltage sag but also for the voltage swell of the input voltage. Experimental results verify that the proposed AVR quickly compensates for the voltage sag and swell of the input voltage.