Modeling and optimal placement of voltage regulator for a radial system

Voltage regulation is an important subject in electrical distribution system. The voltage drop along primary distribution systems has been a crucial operating problem, especially for lengthy feeders, with a significant load concentration at their ends. As the load on a feeder varies the voltage supplied to every customer will also vary. It is the utilities responsibility to keep the customer voltage within American National Standard Institution (ANSI) standard. In order to satisfy the ANSI standard, the utility must have means of regulating the feeder voltage. In view of this, a model of control system for voltage regulator (VR) is developed and tested. The paper presents modeling of control system for voltage regulator, which is On-Load Tap Changing (OLTC) transformer. The control system model is developed using MiPower software. The model is tested for 12 bus and 70 bus radial distribution systems. Further a case study is done for optimal placement of voltage regulator for the said systems. The Placement of voltage regulator is done with help of a two different algorithms. These algorithms help to find the location and number of voltage regulator required for systems. Finally comparison of two algorithms is done to select best method for the placement of voltage regulator. The voltage profile of the systems are improved and real power losses occurred for the systems with VR are less. The first algorithm gave good results with respect to reduction of losses and economical aspects.