【摘要】 随着分布式电源在中低压配电网中参与率的提高,多个微网共存于一个区域配电网的现象越来越多,包含几个微网的微网群能量互补与协调控制技术开始引起广泛关注。文中微网内各分布式电源间信息单向传递,采用基于无功电流一致设计虚拟阻抗的下垂控制方法,更好地实现微网无功功率按比例分配。微网群采用分组一致性算法对各微网进行协调控制,以实现微网间能量互济,群内电压和频率精确控制以及有功和无功按比例精确分配。下垂控制和一致性算法控制策略都属于需要各分布式电源进行实时同步协调的对等控制,为了避免一个微网中投入负载但并未超载,然而却引起整个群中所有DG的动态联动这一问题,本文提出改进的运行模式,即当各微网未过载时各微网独立运行,而若有微网过载或波动过大时自动切换为多微网并联运行的群模式。最后在MATLAB/Simulink平台上搭建微网群仿真算例来验证所提方法的有效性。仿真结果表明所采用的一致性算法能够实现微网群的电压频率稳定以及功率按比例分配,改进的微网群运行模式能够解决对等控制存在的能量损失问题。更多还原

【Abstract】 With the increase of the participation rate of distributed power in the medium and low voltage distribution networks, the coexistence of multiple microgrids in a regional distribution network is increasing.The energy complementary and coordinated control technology of microgrid including several microgrids has attracted wide attention.In this paper, the one-way transmission of information among the distributed power sources in the microgrid is adopted, and the droop control method based on the uniform design of reactive current and virtual impedance is adopted to better realize the proportional distribution of reactive power in the microgrid.The group consistency algorithm is used to coordinate and control the microgrids, to realize the mutual aid of energy among microgrids, the precise control of voltage and frequency within the group, and the precise distribution of active and reactive power in proportion.Droop control and consistency algorithm control strategies belong to peer-to-peer control which needs real-time synchronous coordination of distributed power sources.In order to avoid the dynamic linkage of all DGS in a microgrid without overload, this paper proposes an improved operation mode, namely, when the microgrids are not overloaded, each microgrid operates independently, and if there is microgrid overloaded, each microgrid operates independently or when the fluctuation is too large, it will automatically switch to the group mode of multi microgrid parallel operation.Finally, a microgrid simulation example is built on MATLAB/Simulink platform to verify the effectiveness of the proposed method.The simulation results show that the consistency algorithm can achieve the stability of voltage and frequency and the proportional distribution of power, and the improved operation mode can solve the problem of energy loss in peer-to-peer control.更多还原