Research on the Influence of Distributed Photovoltaic in the Radial Distribution with Multi-transformers Network

It has been changed obviously for the state of power flow, voltage and network loss of distributed network, with the large scale of distributed photovoltaic accessing. In this paper the calculation method of network loss with distributed photovoltaic has been introduced. By simulation with the radial distribution network, the influence has been illustrated on the condition of distributed photovoltaic capacity, grid-connected position or access mode. The conclusions are given. Firstly, the network loss ratio will decrease at first and then increase with output of distributed photovoltaic increasing, which is the V-shaped parabola with increasing slope. Secondly, it should be accessed between the head to the middle point of the line if the capacity of distributed photovoltaic is large. Thirdly, it is suggested chose decentralized accessing mode, while it is necessary to consider coordinated voltage control. And the resolutions of reducing network loss ratio are proposed as using marketing measures, selecting suitable grid-connected position, developing network reconstruction technology and operating voltage control.