考虑三相负荷不平衡的10kV配电网电压损耗计算模型

Calculation Model of Voltage Loss in 10 kV Distribution Network Considering Three-phase Load Unbalance

单相负荷和三相不对称负荷大量接入10 kV配电网所引起的低电压问题日益严峻。为了量化三相不平衡度对配电网电压损耗的影响,并着眼于工程实际,提出了一种考虑三相负荷不平衡的10 kV配电网电压损耗计算模型。通过分析配电线路电压损耗的产生原理,并结合负荷矩的概念,建立了配电线路电压损耗计算的数学模型。考虑三相负荷不平衡对台区变压器电压损耗的影响,并分析三相不平衡度与台变电压损耗的定量关系,建立了三相负荷不平衡下台变电压损耗计算的数学模型。最后,利用某典型低电压台区监测数据进行案例分析。结果表明,所提模型可以有效计算三相负荷不平衡下的10 kV配电网电压损耗,具有实际工程应用价值。

The low voltage problem caused by a large number of single-phase loads and three-phase asymmetric loads connected to the 10 kV distribution network is becoming more and more serious.In order to quantify the influence of the three-phase unbalance degree on the voltage loss of the distribution network,and focus on the engineering practice,a calculation model of the voltage loss of the 10 kV distribution network considering the three-phase load unbalance was proposed.By analyzing the generation principle of distribution line voltage loss and combining with the concept of load torque,a mathematical model of distribution line voltage loss calculation was established.Considering the influence of the three-phase load unbalance on the voltage loss of the transformer in the station area,and analyzing the quantitative relationship between the three-phase unbalance degree and the station transformer voltage loss,a mathematical model for calculating the voltage loss of the transformer under the three-phase load unbalance was established.Finally,a case analysis was carried out using the monitoring data of a typical low-voltage station area.The results show that the proposed model can effectively calculate the voltage loss of the 10 kV distribution network under the unbalanced three-phase load,which has practical engineering application value.