接地网接地电阻在线监测系统的应用研究

摘要

At present,the method of grounding resistance measurement was simple and periodic long,so it was not easy to monitor in real time.Henan Tiantong Electric Power Co.,Ltd.was responsible for the power supply task of China Flat Coal Shenma Group mine area,and has a great security responsibility,because the substation was dispersed,the on-line monitoring of grounding resistance was particularly important.This paper designs a set of grounding resistance on-line monitoring system,and grounding resistance value is tested,making use of different frequency voltage method;in view of the limitations of traditional non double point interpolation method,the test power supply uses pure sine wave and high power signal source,and so multi frequency data acquisition is achieved;the technique of digital frequency selective measurement(ECM) is applied to solve the problem of accuracy of various current interference measurement results;by using digital analysis and filtering technology of military electronic warfare,the measurement accuracy in high and low range is guaranteed.The application of this system has solved the blind spot of the periodic test of the grounding resistance of the company,and ensured the safety of the operation of the power grid in the mining area.%现阶段电网接地电阻测试手段单一,周期性长,不便于实时监测.河南天通电力有限公司担负着中国平煤神马集团矿区供电任务,安全责任重大,由于变电站分散,接地电阻的在线实时监测显得尤为重要.研究设计了一套接地电阻实时在线监测系统,运用异频电压测试法测试接地电阻值;针对传统的双点异频插值法的局限性,测试电源采用纯正弦波大功率信号源,实现多频点采集数据;应用数字选频测量(电子对抗)技术,解决了各种电流干扰测试结果精度的问题;利用军用电子对抗数字化分析滤波技术,保证了在高低量程范围的测量精度.该系统的应用很好地解决了公司接地电阻周期性测试存在的盲区,确保了矿区电网运行安全.