基于拓扑变换的非接触式电压传感器

Non-Contact Voltage Sensor Based on Topology Transformation

设立线路电压监测点获取节点电压数据对电力系统运行状态进行评估,若采用接触式电压传感器在某些无法破坏线路绝缘层的节点处将无法获得电压数据。相对于传统电压传感器,非接触式电压传感器具有装卸简便、施工安全性高、不受线路绝缘影响等优势,将成为未来电压测量装置的发展方向。该文对传统电场耦合式非接触电压传感器测量原理进行分析,针对传统方法下线路与极板间寄生电容无法实地求解的问题提出改进方案。改进后的电压传感器通过拓扑变换法获得一系列原始数据,原始数据经Butterworth数字高通滤波、小波降噪后进行寄生电容计算,最终重构待测电压。对基于拓扑变换的非接触式电压传感器进行稳态响应、暂态响应测试,测试结果表明,改进后的电压传感器具有较好的稳态及暂态性能,幅值与相位偏移较小,且能够较好地复现暂态电压波形,具有实用价值。

Using ohmic-contact voltmeter to establish line voltage monitoring points for power system status assessment cannot acquire the voltage at some point where the insulation is unable to be destroyed. Comparing to ohmic-contact voltmeter, the non-contact voltage sensor has much more advantages on installation, safty and the inflence of the insulation, and will be the futuer trend of voltage monitoring. This paper analyzes the principle of the traditional non-contact voltage sensor based on electric field coupling, and proposes an improved solution to the problem that the parasitic capacitance between the line and the sensor plate cannot be obtained under the traditional method. Passing through the Butterworth digital high-pass filter and wavelet denoising, the improved sensor uses the new method of topology transformation reconstructing the voltage to be measured. Results of the steady-state response and transient response test show that the improved voltage sensor has good steady-state and transient performance, small amplitude and phase offset, and can well reconstruct the transient voltage waveform, which has practical value.