微网孤岛运行的分散自趋优控制策略

A Decentralized Self-optimizing Control Strategy for Islanded Microgrid

提出了一种适用于微网孤岛运行的分散自趋优控制策略,该策略无需微网中央控制器和通信系统即可实现系统的三次分层控制,包括分散一次控制、分散二次控制和分散三次控制。其中,一次控制沿用传统的线性下垂控制策略,保持了微网良好的线性动态特性;二次控制仅借助各台分布式发电机的输出端频率信息即可直接参与系统调频,使微网的频率能够维持在允许的范围内;三次控制采用考虑发电机成本的非线性下垂控制策略,使各台分布式发电机遵循等微增率准则,实现微网的优化运行。此外,通过设计不同时间常数的低通滤波器,使三次分层控制实现了动态解耦,使控制策略既能满足微网静态特性的要求,又具有良好的动态特性。最后,由仿真算例验证了所提控制策略的有效性。

A decentralized self-optimizing control strategy for islanded microgrid is proposed,which is capable of realizing three-level hierarchical control of the system without microgrid centralized controller and communication system, that is the decentralized primary control(DPC),the decentralized secondary control(DSC)and the decentralized tertiary control(DTC). DPC uses the traditional linear droop control strategy to maintain microgrid the good linear dynamic performance,DSC makes each distributed generator(DG) participate in system frequency regulation directly only by their output frequency information so that the microgrid frequency can be restored within the permitted range,and DTC uses the nonlinear droop control strategy considering the generator cost to make each DG meet the equal incremental principle in order to realize the optimal operation of microgrid.In addition,the low-pass filters with different time constant are designed to decouple the microgrid dynamically to meet the requirements for both static and dynamic characteristic of microgrid.In the end,the effectiveness of the proposed control strategy is verified by a simulation example.