Effect of Capacitors on Frequency of OLTC Tap Changes in the Presence of Wind Generation

Abstract

Installation of a wind power distributed generator in a distribution system alters the reactive power drawn by the system. This affects the load bus voltages. Any deviation in load bus voltages from their limits is sensed by an on load tap changer of a transformer and it responds to maintain the bus voltages within their limits. The reactive power requirements of a wind generator vary due to the intermittent behaviour of wind, which will in turn vary the bus voltages. This has an affect on number of tap changings of a transformer. Frequent tap changing of a transformer increases wear and tear of it and ultimately reduces the life of it. A mathematical model is developed to analyze the voltage sensitivity at a load bus to the tap change of a transformer under different scenarios and conditions in the distribution system. A possible solution to reduce the number of tap changings is presented in this paper.