Evaluation model of transformer overload capacity considering multifactors

XIA Yiqiao1, GUO Chuangxin1, CHEN Yufeng2, YANG Yi2, LIU Hui2

（1.School of Electrical Engineering, Zhejiang University, Hangzhou 310027, China;
2.Electric Power Research Institute, Shandong Power Supply Company of State Grid, Jinan 250002, China）

Abstract: Aiming at the problem of suspending power grid construction and solving the demand of high power consumption, and the problem of only considering the hot spot temperature or top oil temperature, a new model based on hot spot temperaturefailure load probabilityeconomytransformer load capacity (HFETLC) was proposed. Based on the modified hot spot temperature model and the transformer failure probability model, the constraints of hot spot temperature and fault probability were determined. Fulfilled the above constraints, and combined the economic losses and economic benefits, the conception of probability loss was proposed to study the influence of the economy on the overload operation. The results indicate that the modified hot spot temperature model could more accurately characterize the actual hot spot temperature. By analyzing the influence of transformer service time and planned running time on short term overload operation, the model provides comprehensive suggestions for decisionmaking and proposes the theoretical support for the power grid risk assessment, which is driven by the quantitative analysis of multifactors in the outage maintenance scene.

Key words: transformer; overload operation; HFETLC model; modified hot spot temperature; probability loss