DefinePK

Abstract

There are many custom power devices and they are divided in two groups: network-reconfiguring type and compensating type. The network reconfiguring group includes the following devices: solid-state current limiter (SSCL), solid-state breaker (SSB) and solid-state transfer switch (SSTS). These devices are much faster than their mechanical counterparts. The compensating devices either compensate a load, correcting its power factor, unbalance etc., or improve the quality of the supply voltage. These devices are either connected in shunt or in series or a combination of both. The compensating group includes distribution static compensator (DSTATCOM) to compensate for load reactive power and current harmonics, dynamic voltage restorer (DVR) for voltage support, and unified power quality conditioner (UPQC) for both current and voltage compensation. The present work focuses on the last custom power device UPQC, which is a combination of a shunt and series device and can combine the functions of these two devices together.