An Arcless Voltage Regulator Based on Hybrid Tap Changing Topology

Step voltage regulators have been widely used in power distribution systems. Step-type voltage regulators have used tap changing mechanisms which arc under oil during tap changes. However, electric arc in tap changer operation imposes constraints on conventional voltage regulators when it comes to life time and maintenance period. This paper proposed a new scheme of arcless voltage regulator featured with hybrid tap changing topology. Eletromechanical and semiconductor switching devices are paralleled as a hybrid switch which can eliminate arc during the tap changing operation. The practical circuit design is also presented to solve voltage and current stress issues to achieve a better performance. The proposed solution is based on the existing Step Voltage Regulator (SVR) but improves the reliability and the life time of the SVR.