Effects And Analysis Of Flexible AC And DC Devices On Operation Mode Of Distribution Network

The government is vigorously promoting the sustainable energy development and the process of urbanization is accelerating. In this context, many new changes have appeared in requirements of power supply and access equipment type of existing urban AC distribution network. These changes have brought new problems and challenges to the reliable operation of distribution network. Flexible AC and DC devices have the advantages of flexible control and fast response. The AC and DC distribution network which has used many flexible AC and DC devices will become a major trend of distribution network in the future. This paper focuses on how to use flexible AC and DC devices to solve the power quality problems of AC and DC distribution network. First, hybrid energy storage is used to control voltage in DC distribution network and the existing control strategy and remaining problems are analyzed. On this basis, a new super capacitor battery control strategy is proposed. Secondly, the VSC-HVDC control strategy is also analyzed and a new control strategy is proposed which can make use of the device capacity more effectively to uplift load voltage. Thirdly, a new STATCOM control strategy is proposed and a simulation is used to verify the effectiveness of the control strategy. Finally, a rapid power coordinated control method is applied to enhancing the overall voltage level of distribution network.In this paper, the energy storage, VSC-HVDC, STATCOM and power coordinated control strategies are used to solve the problems of DC voltage fluctuation, voltage sag and the overall voltage deviation in distribution network, which will provide some useful experience to the further research in power quality of distribution network.