基于模糊逻辑的低压配电网高比例户用光伏无功控制策略

摘要

In order to solve the problem of voltage limit violation and voltage fluctuation caused by the high-proportion residential photovoltaic(PV)power integrated into low-voltage distribution networks,and reduce the network operation risk,a residential PV reactive power control strategy based on Mamdani fuzzy inference is proposed.The strategy uses the voltage excursion and PV active power variation rate as two inputs to adapt to voltage limit violation and voltage fluctuation scenarios, respectively.Fuzzy rules are developed according to the logical relationship between the input and the output of inverter reactive power.Then the reactive power output of the PV inverter is obtained via the defuzzification process.The parameters of the fuzzy triangular membership functions of different buses are coordinated and designed based on the voltage sensitivity theory. Therefore,an effective utilization of reactive power capacity of residential PV inverters can be achieved.Finally,the simulation results show that the proposed strategy can effectively mitigate the voltage limit violation and voltage fluctuation.In contrast with the conventional reactive power droop control of inverters,the voltage limit violation and voltage fluctuation are effectively suppressed.%为了解决高比例户用光伏接入低压配电网所带来的电压越限和电压波动问题,降低网络运行风险,提出了一种基于Mamdani模糊推理的户用光伏无功控制策略.该策略引入了模糊逻辑思想,采用并网点电压偏移量和光伏有功变化率作为输入量以分别适应电压越限和电压波动场景,根据输入量与逆变器无功输出量之间的逻辑关系制定了模糊规则,经去模糊化过程得到光伏逆变器的无功输出.利用电压灵敏度理论对不同节点输入量的三角形隶属度函数参数进行协调设计,充分利用了各节点户用光伏逆变器的无功容量.仿真算例结果表明,所提方法能够有效缓解电压越限和电压波动问题,相对于传统逆变器无功下垂控制,电压越限和电压波动均得到有效抑制.