计及负荷等值阻抗的配电网合环转供电分析模型

An Analysis Model for Power Transfer from Loop Closing in Distribution Network Considering Load Equivalent Impedance

配电网合环转供电已经成为转移负荷的常用手段,配电网合环模型是进行合环分析的关键。现有的合环转供电分析模型大都忽略负荷阻抗,会导致合环电流的计算出现较大偏差。该文考虑负荷对合环稳态及暂态过程的影响,基于馈线首末端少量微型同步相量测量装置(μPMU)的实时量测信息对负荷进行等效处理,提出计及负荷等值阻抗的合环转供电分析模型。在该模型的基础上,利用叠加原理对合环稳态电流与冲击电流的计算进行了详细分析,针对目前求解合环冲击电流所存在的不足,提出基于最佳频率法求解合环冲击电流的一种有效方法。基于PSCAD/EMTDC仿真软件搭建具体的算例模型,验证了该文所提模型与计算方法的有效性。

Loop closing of distribution network to transfer power has become a common method for load transfer,and loop closing model of distribution network is the key to loop closing analysis.Most of the existing analysis models for power transfer from loop closing ignore load impedance,which can cause large deviations in the calculation of loop closing current.Considering the influence of load on the steady-state and transient processes of loop closing,this paper equivalently processes the load based on the real-time measurement information of a small amount of micro-phasor measurement unit(μPMU)at the head and end of the feeder,and proposes a loop closing analysis model for power transfer considering the equivalent impedance of the load.On the basis of this model,the superposition principle is used to analyze the calculation of steady-state current and surge current in detail.In view of the shortcomings in solving the surge current of loop closing at present,an effective method for solving the surge current of loop closing on the optimum frequency method is proposed.A concrete example model is built based on PSCAD/EMTDC simulation software,which verifies the validity of the model and calculation method proposed in this paper.