Voltage Enhancement of GRA Phase 2 Distribution Network via Static Synchronous Compensator (STATCOM)

Abstract

This research examines the GRA phase 2 11kV distribution network for enhanced voltage profile. After an assessment of the system via load analysis (Newton-Raphson) with the aid of Electrical Transient Analyser Program  (ETAP) 20 software, it was found that Bus 5: 93.25%, Bus 10: 92.77%, Bus 13: 93.50% are the critically weak buses in the network because they violate the statutory limit condition of 0.95-1.05 pu this is due to small voltage magnitude that arises as a result of overloading of the power transformer which operates near its highest limit. This has caused untold hardship for those dwelling and doing business around that vicinity who were left with no choice but to get means of power supply elsewhere. These weak buses are selected for sensitivity check (V-Q) to find the actual position for the installation of the STATCOM. Bus 10 was chosen as the optimum location for STATCOM placement for reactive power compensation in the GRA phase 2 distribution network. Total power loss without the STATCOM is 59.32 kW + j78.91 kVAr, while with STATCOM of 6.25MVAr, it is 34.89kW + j43.69kVAr. The result obtained shows that the bus voltage of the critically loaded buses has be en enhanced as indicated in their operating percentages: Bus 5 having 100.24%, Bus 10, 100% and Bus13, 99.04%, which shows that the installation of the STATCOM FACTS device impacted significantly on the network. Compared with SVC and other FACTS devices, STATCOM performs better in fast response to the real-time implementation of dynamic compensation, production, and absorption of reactive power. Also, in restraining voltage fluctuation, flickers, and parallel resonance, more indoor/outdoor installation space must be needed, as well as better economic consideration. It was also found that the best possible location of the STATCOM is flexible; it varies depending on the fault location.