Improving the voltage regulation of secondary feeders by applying solid-state tap changers to MV/LV transformers

Voltage regulation at the subtransmission and distribution levels strongly relies on the use of transformer tap changers, implemented nowadays by means of sophisticated electromechanical mechanisms. The possibility of replacing such slow and prone-to-wear switches by electronic devices has been the subject of much interest in the last few veal's, particularly at subtransmission levels. In this paper, the application of on-load electronic tap-changers to MV/LV distribution transformers is proposed and the operational benefits from their widespread use on a sample realistic feeder, both at normal and emergency conditions, are illustrated.