Study on Daily Line Loss Calculation Based on Operation Data and Resistance Characteristics of Low Voltage Distribution Transformer Area

Transformer area line loss is a relatively large part of distribution network line loss, but also an important part of power grid energy saving and efficiency. This paper presents a daily line loss calculation method based on the transformer operation data and the resistance characteristics of the distribution transformer area when the topological structure of the distribution area and operation data of users’ electricity meter are unknown. Firstly, the equivalent circuit model of the transformer and load side is established. Then according to the measured electric quantity data, the characteristic of "virtual line resistance " is calculated. Then the resistance characteristics are combined with the measured voltage, current and active power data of the transformer, and the iForest isolated forest algorithm is used to detect data outliers. After eliminating outliers, a reasonable line loss estimation model is established by using regression analysis method in machine learning for a large number of measured data. In this paper, the actual data of power grid transformer are used to verify the results, which can provide a basis for the line loss management and assessment of transformer areas.