Formulation of maximum voltage index for power distribution system containing grid-connected photovoltaic system

Abstract

Solar energy is one of the favourite renewable energies in Malaysia due to its relatively consistent power generation throughout the year. The solar panel price drops drastically compared to the last few decades, making it affordable to the public. In Malaysia, the government has introduced Feed-in-tariff (FiT) and Net Energy Metering (NEM) to catalyse renewable energy generation, mainly through solar energy. However, high penetration of solar energy has caused several electrical issues such as voltage fluctuation and the protection system's incoordination. In this research, the voltage stability of a bus in a distribution system containing photovoltaic systems are investigated by the concept of power flow of two bus model. The severity of reverse power flow in a distribution system is determined by the proposed index named Maximum Voltage Index (MVI). The main objectives of this report are to formulate a maximum voltage index that can predict the proximity to the maximum voltage of a bus due to reverse power flow from the photovoltaic generator; to validate the validity of the formulated index by using ETAP software; to analyse the voltage collapse event in radial type distribution power system due to reverse power from photovoltaic systems. The results show that MVI is able to predict maximum voltage event of distribution system satisfactorily. Hence, an early correction action can be taken to rectify the situation. Lastly, MVI can be a useful indicator to predict maximum voltage and voltage collapse event for researchers as well as regulatory body.