the effect of the static transfer switch on power quality of power system

Voltage drop and voltage fluctuations are one of the most important power quality problems of power networks. there are so many sensitive loads like electronic controllers, microprocessors and instrumentations like plcs in power system that are very sensitive to disturbances and their operation could be affected easily by power quality problems. uninterruptable sources and static switch are used to prevent disturbance in sensitive loads. when a fault occurred in main source side, a static switch can disconnect the main source and connect the alternative source in few milliseconds. in this paper, the impact of static transfer switch performance on power quality in presence of any faults such as one phase, two phase and tree phase faults and motor starting in power system are studied.