Minimum Static VAR Compensation Capacity for Bad Voltage Drop Buses in Power Systems

Abstract

The quality of the electric power system must be maintained properly, one of which is voltage. Under certain operating conditions, the bus voltage may drop below its minimum level, called bad voltage. A large reactive load can cause a voltage drop across the bus or the location of the bus is far from the generator stations, so that the line impedance has a large value. One technique to increase the voltage is through compensation technique. This paper presents the determination of the minimum statistical VAR compensation for increasing the voltage to the minimum safety limit. The methodology creates a compensating model for bad bus voltages. Electrical quantities (voltage, power and system losses) are calculated through the power flow technique. The compensating capacity is increased until the voltage rise reaches its minimum security limit. The simulation results on the IEEE 9 bus system show that the voltage increases on all buses with minimal compensation on buses 5 and 8, and can save up to 1.