采用负荷电量计算低压配电台区理论线损的牛拉法

为计算低压配电台区理论线损和利用远程自动抄表系统提高管理线损水平,提出一种采用负荷电量计算低压配电台区理论线损的牛拉法。该方法基于等值电阻法和用户电能表实抄电量,通过引入线路负荷曲线形状系数与平均负荷电流的关系和三相负荷不平衡线损修正系数建立以台区理论线损为变量的数学模型。给出了运用牛拉法求解该模型的实现过程。算例分析表明,提出的方法不仅能够计算低压配电台区的理论线损,而且能够为识别不明线损提供信息。

Newton-Raphson method for theoretical line loss calculation of low-voltage distribution transformer district by using the load electrical energy

In order to calculate the theoretical line loss of low-voltage distribution transformer district and improve the line loss management level by using automatic meter reading system, a Newton-Raphson method to calculate the theoretical line loss of low-voltage distribution transformer district by adopting the load electrical energy is proposed. On the basis of the equivalent resistance method and the electrical energy acquired from the watt-hour meters of customers, the mathematical model of regarding theoretical line loss of transformer district as a variable is created. The model introduces relationship between load shape coefficients and the average load current, and the line loss modified coefficient of unbalanced three-phase load. The procedure of the Newton-Raphson method to solve the model is presented. Case analyses show that the proposed method can not only calculate the theoretical line loss of low-voltage distribution transformer district, but also provide the information to identify unknown line loss.