典型架空输电线路地线电磁取能等效电路的分析

Analysis of Equivalent Circuit for Tapping Electromagnetic Power From Overhead Ground Wires of Typical Transmission Lines

地线取能是输电线路在线监测装置较为理想的供电方式,其关键技术问题之一是如何获得足够的功率。取能功率的最大化必须以其等效电路为基础进行阻抗匹配设计。同时,取能电路输出电压的稳定性、可靠性也必须以其等效电路参数为基础。为此,以四川电力公司所辖的某220k V架空输电线路为例,对地线取能等效电路进行推导,并对其参数进行简化,在此基础上对地线最大取能功率进行计算与评估。此外,结合EMTP-ATP仿真对相关因素对等效电路的影响进行分析,供取能设计参考。最后,根据现场测量结果验证等效电路参数的理论计算结果。

To tap power from overhead ground wires of transmission lines is an ideal method for power on-line monitoring devices. One of the key technical problems of this method is to obtain enough power. To make the best of the obtained power from the ground wires, concerned impedance matching design has to be used based on the equivalent circuit. Meanwhile, the stability as well as the reliability of the output voltage of the power tapping circuit, should also be based on the parameters of the equivalent circuit. Therefore, with a 220 k V transmission line under Sichuan Electrical Power Company as example, the equivalent circuit for tapping electromagnetic power from ground wires is deduced, and the equivalent circuit parameters were simplified. Based on the simplified parameters the maximum power from the ground wires is calculated and evaluated. Besides, combining with the simulation with EMTP-ATP, effects of related factors on the equivalent parameters are analyzed for the reference of design of power tapping. Finally, the calculation for the equivalent circuit is verified with onsite measurement results.