一种基于耦合电容的电网过电压在线监测技术研究

Research on Online Monitoring Technology of Power Grid Overvoltage Based on Coupling Capacitor

电力系统过电压监测与防护一直是高压智能电网建设领域里关注的重点。设计了一种适用于电网过电压在线监测的耦合电容传感器,该传感器高低压臂分别由传感器与大地以及传感器与高压导体之间杂散电容组成,对低压臂上信号进行采集和处理,即可获取高压导线上过电压数据。对传感器结构设计、参数获取方法以及监测原理等进行分析,并结合实际挂网运行经验,最终确定了传感器各部分元件的参数。然后对传感器进行相关试验,试验结果表明,传感器测量精度较高,并且雷电冲击响应特性良好,结合实际工程应用案例分析,表明本文过电压在线监测技术可满足实际电网过电压监测的需求。

Overvoltage monitoring and protection of power system is always the focus in the field of high voltage smart grid construction. A coupling capacitance sensor which can be used for power grid overvoltage on-line monitoring is designed. The high and low voltage arm of the sensor is composed of the stray capacitance between the sensor and the earth and the stray capacitance between the sensor and high-voltage conductor respectively. Collecting and processing the signal on the low voltage arm, and then the voltage data of high voltage wire may he obtained. This paper firstly analyzed the structure design of the sensor, the method of parameter acquisition and the detection principle, and determined the parameters of each part of the sensor through the actual operation experience. The paper then test the senor and results show that the sensor has high measurement precision, and impulse response characteristics, combined with analysis of actual engineering case, it can be concluded that the online monitoring technology can meet the reouirements of voltage monitoring in actual power grid.