Improvement of Defense Scheme Operation by Considering Load Profile of Interbus Transformer for Sub Java Electrical System

Abstract

The electrical blackout on August 4, 2019, in several areas of Jakarta and surrounding areas took a long time to recover and the vital loads lose electrical supply. This power outage indicates that there is a weakness in the electrical defense scheme. Based on the conventional standard, when the frequency declines due to a fault in the power system, several buses must release loads without considering existing load circumstances. The impropriate scheme for load shedding will trigger a catastrophe as the capacity of the electrical source is limited. In the subsystem of the large electrical network, several groups of loads are supplied by an inter-bus transformer which accepts electrical energy from other networks and generators. As the transformer has limited capacity and the transmission network's characteristics are strongly influenced by the line parameters and the energy passing through, then this paper proposes a defense scheme that considers the combination of real and existing loads carried by the IBT and the rate of frequency decline. It is expected that the proposed scheme will prevent the power system fall into a worse situation, accelerate recovery conditions and maintain the frequency profile. The work takes a sub-Java electrical system with two inter-bus transformers included.