Research on Optimal Control of AC-DC Hybrid Distribution Network

It is hard to optimize power flow and operating status of hybrid AC/DC distribution network with traditional control strategy, so this paper proposed a hierarchical control strategy with different voltage scales. In the first layer, different converter stations maintain stable operation of power system with different control strategy; In the second layer, when power fluctuations of system are large, converter stations change its operation mode to balance voltage fluctuation of DC side; In the third layer, energy optimal dispatch system calculate different converter stations' control reference to reduce power loss of system. When operation of system change, systems' stable operation is maintained by switching of control strategy in different layer. The simulation using Matlab/Simulink shows that this control strategy can reduce power loss and system can operate stably even in communication failure.