基于动态三相不平衡度的配电网线损计算方法研究

Calculation Method of Distribution Line Loss Based on Dynamic Three-phase Unbalance Degree

均方根电流法、平均电流法、最大电流法等计算线损的方法应用于三相不平衡程度较重的区域存在一定误差。提出了一种基于动态三相不平衡度的配电网线损计算方法。首先通过对三相负荷电流的动态采集,计算得到台区三相不平衡度。对台区结构进行分析,根据台区负荷特征将其划分为不同的计算区域。根据不同计算区域的用户电量等参数,运用以居民用户总用电量替代电能表容量的改进等值电阻法得到其等值电阻的计算值。利用等值电阻法计算线损时考虑三相不平衡度的动态影响,得到基于动态三相不平衡度的配电网线损计算方法。实际案例验证了所提算法的有效性。

There is a certain error when applying the method of calculating line loss to a region with heavy three-phase unbalance degree,such as root mean square current method,average current method,the maximum current method,etc.Therefore,the paper proposes a calculation method of distribution line loss based on dynamic three-phase unbalance degree.The three-phase unbalance degree of transformer region is calculated using the dynamic acquisition of three-phase load current.In order to calculate the equivalent resistance,the structure of the transformer region is first analyzed,and it is divided into different calculation areas based on the load characteristics of the transformer region.According to the parameters such as electricity data for users in different calculation areas,the calculated equivalent value of the equivalent resistance is obtained by using the improved equivalent resistance method with total electricity consumption for residential users.The three-phase unbalance degree is then introduced into the improved equivalent resistance method to obtain the line loss.The actual case verifies the effectiveness of the method.