配电网三相负荷不对称的线损分析

通过分析三相不平衡线路的线损,用全电流经坐标转换的方法研究了角度不对称时的三相不平衡对线损的影响,推导出了线损增加率与相不平衡度的关系公式,并给出了配网中常见几种负荷不对称时的线损分析结果。推导出的线损增加率与相不平衡度的关系公式,大大简化了分析计算工作,可以直接用于配电网三相负荷不对称的线损计算中。算例结果表明,考虑角度不对称时的线损增加率更接近于现实值,对准确地计算配网中的线损更有指导意义。

Circuit loss analysis of three-phase unbalanced circuit in distribution network

The circuit loss rate is an important economical technical specification of power supply,while at the same time it is a symbol that measures enterprises management level.The condition that circuit loss is affected by three-phase unbalanced circuit with angle asymmetry is studied in the method of full current transformed after the coordinates.Then the relational formula of circuit-loss increment rate and unbalanced degrees of phases is deduced.What is more,the exceptional cases of circuit-loss increment rate which is caused by the three-phase load unbalanced distribution way is offered.The numerical result with a test indicates that when the angle asymmetry is considered,it approaches the realistic value nearer and is a better method to accurately compute the rate of circuit loss in power distribution systems.