Transient Temperature Calculation and Multi-Parameter Thermal Protection of Overhead Transmission Lines Based on an Equivalent Thermal Network

Energies

Wei Wang¹  Xiaofu Xiong¹  Jing Chen²  Jian Hu²  Jian Wang² 

[1] System Security and New Technology, School of Electrical Engineering, Chongqing University, Shapingba District, Chongqing 400044, China;;State Key Laboratory of Power Transmission Equipment &

关键词: overhead transmission line;    overload cascading tripping;    equivalent thermal network;    transient temperature;    thermal protection;   

DOI  :  10.3390/en12010067

来源: DOAJ

【 摘 要 】

The overload degree of a transmission line is represented by currents in traditional overload protection, which cannot reflect its safety condition accurately. The sudden rise in transmission line current may lead to cascading tripping under traditional protection during power flow transfer in a power system. Therefore, timely and accurate analysis of the transient temperature rise of overhead transmission lines, revealing their overload endurance capability under the premise of ensuring safety, and coordination with power system controls can effectively eliminate overloading. This paper presents a transient temperature calculation method for overhead transmission lines based on an equivalent thermal network. This method can fully consider the temperature-dependent characteristics with material properties, convective heat resistance, and radiation heat and can accurately calculate the gradient distribution and response of the conductor cross-section temperature. The validity and accuracy of the proposed calculation method are verified by a test platform. In addition, a multi-parameter thermal protection strategy is proposed on the basis of the abovementioned calculation method. The protection can adequately explore the maximum overload capability of the line, and prevent from unnecessary tripping to avoid the expansion of accidents. Finally, the validity of the proposed protection is verified by the modified 29-bus system.

【 授权许可】

Unknown