Transmission line rating method based on security constraint and economy analysis
GAO Shi1, YAN Min na1, WANG Ming wei1, LOU Xian si2, ZHANG Yu2, GUO Chuang xin2
(1.Guiyang Electric Power Supply Bureau, Guiyang 550002, China;
2.School of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)

Abstract: Aiming at the security and economy problem of transmission line rating，a transmission line rating method based on security constraint and economy analysis was proposed. This transmission line rating method consisted of three main steps: temperature verification, failure rate verification and economy analysis. The real time temperature of transmission line could be calculated by heat balance differential equation. A short term reliability model of transmission line based on the PHM (proportional hazard model) was presented in this paper. A computing method of relative aging rate of transmission line based on empirical formula of tensile strength loss was proposed. The economy of transmission line rating was described from three terms including transmission profit, transmission loss cost and life loss cost. The results indicate that the proposed transmission line rating method can achieve a balance between security and economy. The final rating plan obtaines by the method satisfies the constraints of temperature and failure rate, and it is economical in the meanwhile.

Key words: transmission line; heat balance analysis; tensile strength; proportional hazard model; short term reliability; relative aging rate