计及分布式微源控制特性的微网无功环流抑制

Reactive Power Circulation Suppression in Micro-grid WithDistributed Generation Control Characteristics

针对单元输出功率控制(UPC)和馈线潮流控制(FFC)不同控制模式下,微电网分布式微源(DG)之间的有功/无功功率均分控制特性进行了分析。受线路阻抗和本地负荷等的影响,DG因机端输出电压产生误差,进而生成无功环流。针对这一问题,这里提出了一种基于无功闭环控制的DG Q/U下垂特性自适应调节控制方法,根据下垂特性中电压给定参考值与逆变器输出电压的差值自动平移Q/U曲线,有效抑制了DG之间的无功环流。最后,通过搭建3台DG构建的微电网动模实验平台,分别对线路阻抗和本地负荷参数对DG无功均分控制特性影响进行了实验分析,并验证了所提出的无功环流抑制策略的有效性和可行性。

Based on the different control modes of unit output-power control(UPC)and feeder flow control(FFC),the control characteristics of active/reactive power equalization between distributed generation(DG)of micro-grid are analyzed.Due to the influence of line impedance and local load,the distributed micro source produces errors due to the output voltage of the machine end,and then generates reactive power circulation.To solve this problem,an adaptive control method of DG Q/U droop characteristics based on reactive closed-loop control is proposed.According to the difference between the given voltage reference value and the inverter output voltage in the droop characteristics,the QIU curve is automatically shifted,and the reactive power circulation between distributed DG is effectively suppressed.Finally,the effects of line impedance and local load parameters on the equalization control characteristics of DG reactive power are analyzed experimentally by setting up a dynamic model experiment platform of three DG,and the effectiveness and feasibility of the reactive power circulation suppression strategy proposed are verified.