Voltage regulation of distribution networks using inverter reactive power functionality — Australian utility experience

Electrical distributors in Australia are experiencing high penetration levels of small scale distributed generation, such as solar photovoltaic systems, particularly being installed on houses that are connected to the Low Voltage network. Distributed generation is challenging the traditional operating paradigm and can result in occurrences of voltage rising to the point where it goes above safe limits, or result in the inverter energy systems continuously "tripping" and being unable to generate. Reactive power functionality in inverters provides a means to effectively reduce the amount of attributed voltage rise on the network, ultimately allowing more and larger inverters to be connected to the grid while ensuring the network remains within a safe voltage range. This paper presents the results of Ergon Energy's detailed investigation into the application of inverter reactive power functionality through a desktop study, modelling, laboratory testing and field trials. This study confirmed the theory that customer owned inverters with reactive power functionality can be utilized to overcome or prevent voltage rise issues on the electricity network.