Research And Application On Var Compensation Of The Distribution Network

Var compensation is an important condition for the safe and economic operation of the distribution network, which is related to whether the users can get safe and high-quality power. However, there has long been a problem of insufficient reactive power in most of the distribution networks in our country, which will cause great loss and threaten safe operation of the network. Therefore, research on Var compensation of the distribution network is significant for the safe and economic operation of the distribution network.There are two main aspects in the research on Var compensation of the distribution network: research on Var compensation optimization theory and research on Var compensation equipments. Based on certain configuration and optimization principles, optimized configuration of Var compensation location and capacity can effectively reduce system losses and improve the power quality of the distribution network. The commonly used Var compensation equipments include shunt capacitors, static Var compensator and static Var generator, that can be used properly according to application situation and economic analysis.Firstly, basic Var compensation theories is studied including the principle of Var compensation, the analysis of influence on the distribution network and Var compensation optimization theory. Secondly, working principles and control methods of the commonly used Var compensation equipments are studied, including shunt capacitors, static Var compensator and static Var generator. Finally, working principle and control strategy of STATCOM based on Modular Multilevel Converter(MMC) are studied, including working principle and modulation strategy of MMC, DC side and AC side control strategy of MMC-STATCOM. A MMC-STATCOM simulation module is built in PSCAD/EMTDC to verify the studied control strategy.