微网综合控制与分析

考虑到微网内分布式电源和负荷所具有的分散性,根据分布式电源的类型以及与储能装置的不同组合方式,采用不同的控制策略分别进行了相应控制器的设计。基于下垂特性的电压/频率(V/f)控制实现了负荷功率变化时不同分布式电源间变化功率的共享,且在微网孤岛运行时能为微网系统提供频率支撑;PQ控制可根据实际运行情况实现分布式电源有功和无功功率的指定控制。通过对微网孤岛运行模式和联网运行模式之间切换、孤岛模式下切/增负荷以及微网内某一电源功率变化3种情况下的运行特性进行分析,获得了微网中相应分布式电源的功率、电压、电流及系统频率的变化规律,证明了PQ-V/f综合控制策略的正确性和有效性。

Synthetical Control and Analysis of Microgrid

Considering decentralization of the distributed generation units and loads in the microgrid and concentrating on generation types and models of the storage devices, different control strategies are used in controller design for the distributed generation units. The generation units adopting V/f control method based on the droop characteristics can facilitate load power sharing when the powers of loads vary, and can also maintain the system frequency when a unit fault occurs and the microgrid islands. And the generation units adopting PQ control method can export the referenced active and reactive power in operation. Then, the operation variations of the microgrid are respectively analyzed when it runs from grid-connected mode to islanding mode or vice versa, when it runs with load changes in islanding mode and runs with the generated power of distributed power source varied suddenly. The corresponding rules of the power, voltage and current for each distributed power source and the frequency for the microgrid are obtained. The simulation results show the correctness and validity of the PQ-V/f synthetical control scheme.