Adaptive local voltage control and loop testing of distribution network with distributed generation

This paper describes an adaptive local voltage control method acting on tap changing transformer in the primary substation of a distribution network, to provide an adequate reactive power transfer from the transmission network to the distribution network. The proposed method uses distribution state estimator and automatic voltage reference setting algorithm. It measures a number of essential real-time measurements from the critical network nodes to carry out state estimation for a network. Based on the network state assessments the method implements an adaptive voltage reference setting algorithm to provide an adequate voltage reference setting for an automatic voltage relay. The proposed method and its implementation are described. A closed-loop testing facility, based on a real time digital simulator, was constructed to test the proposed method under various load and DG conditions. The results show how this technique may be used to maximise DG that can be connected to a distribution feeder.