考虑分布式光伏电源接入模式的低压配电网不平衡线损计算方法

Calculation Method of Unbalanced Line Loss in Low-Voltage Distribution Network Considering the Access Mode of Distributed Photovoltaic Generation

日益增加的户用光伏发电系统改变了配电网的潮流分布,同时对配电网的线损产生显著影响。为了便于量化分布式光伏电源(distributed photovoltaic generation,DPG)接入三相四线制低压配电网的运行经济性,文章以三相不平衡线损为研究目标,首先建立了适用于低压配电网平衡态和不平衡态的线损计算模型;通过引入DPG接入模式、位置及容量3种要素,建立DPG不同接入模式下的线损变化量模型;以此为基础,提出一种考虑DPG接入模式的有源低压配电网的三相不平衡线损计算方法。在进行计算时,所提方法既可利用实时电流数据,也可利用易采集到的有功电量数据进行计算。最后,以低压配电网的典型参数为例验证了该方法的准确性与可行性,说明此方法可为DPG单相、三相接入低压配电网的线损计算提供参考依据。

The increasing number of household photovoltaic power generation systems has changed the power flow distribution of the distribution network,and at the same time has a significant impact on the line loss of the distribution network.In order to quantify the operating economy of distributed photovoltaic generation(DPG)connected to the threephase four-wire low-voltage distribution network,this paper takes the three-phase unbalanced line loss as the research objective,and firstly establishes a balanced and unbalanced line loss calculation models suitable for low-voltage distribution network.By introducing three influencing factors of DPG access mode,location and capacity,the line loss variation model under different DPG access modes is established.A model for estimating the three-phase unbalanced line loss of the active low-voltage distribution network considering the DPG access mode is proposed.This method can be calculated by using both real-time current data and easily collected active power data.The accuracy and feasibility of this method is verified by taking typical parameters of low-voltage distribution network as an example,and the method can provide reference basis for line loss calculation of DPG single-phase and three-phase access to low-voltage distribution network.