A review on voltage control using on-load voltage transformer for the power grid

Abstract

Voltage control is an important method for regulating the feeder voltages in power systems. Various voltage control methods are used by distribution Gridoperators in order to maintain the voltages to be with in an acceptable voltage level. Traditional OLTC (on-load tap-changer) and improved OLTC are most applied. However the traditional voltage control techniques are nolonger leading in technically because of the long arcing time and the high investment. Combining power electronics and OLTC is the future. The use of a thyristor for controlling the current can achieve arc-free operation in power electronic switch OLTC with unparalleled advantages in terms of safety and invest control.