Optimal coordinated control of OLTCs using Taguchi method to enhance voltage stability of power systems

Abstract

On-load tap changer (OLTC) plays a significant role to regulate the voltage of the power system. Although some time, secondary voltage of an OLTC is pulled down when tappings are raised to restore the voltage level. This situation may finally lead to voltage collapse. To address this problem, the behavior of tap setting of OLTCs is investigated, and critical transformer and its allowed range of tap settings is identified in the paper. This paper also proposes a Taguchi based method to find optimal tap settings of OLTCs including critical transformer to improve the voltage stability margin and decrease the real power loss of the system. The proposed method is tested on IEEE 30-bus system to validate its applicability.