变压器局部放电特高频在线监测系统的研究

An on-line monitoring system of ultra-high-frequency PD for transformers

本文研究了变压器局部放电特高频在线监测系统。基于混频技术研制了系统硬件,它包括特高频传感器和特高频接收机。基于虚拟仪器技术开发了系统软件,它分为数据采集、数据分析处理、数据库和上下位机通讯四大功能模块。在实验室中检测了变压器绕组的局部放电,结果表明:该系统可以有效地提取中心频率在400～800MHz之间(最小步长5MHz)、带宽为10、20、40或80MHz的特高频局部放电信号,能准确地计算放电相关参数;具有测量频带宽、抗干扰能力强、工作稳定性好等优点,可用于变压器局部放电特高频在线监测和智能化诊断。

An on-line monitoring system of ultra-high-frequency (UHF) PD was investigated for transformers in this paper. Based on frequency mixing technique, the hardware of this system, including UHF sensor and UHF receiver, was developed. The software of this system, consisting of data acquisition, signal processing and analysis, database and data communication, was constructed using National Instruments' Measurement Studio software. By using this system, the PD of transformer windings was measured. Experimental results show that the system can effectively measure the time and the amplitude of the high-frequency (adjustable center frequency between 400～800 MHz with minimum steps of 5 MHz) and narrowband (10, 20, 40 or 80MHz) signals emitted from PD, and accurately calculate phase resolved PD patterns and statistical operators. This system has wider bandwidth, stronger ability of interference suppression, and higher stability, and can be useful for on-line monitoring and intelligent diagnosis of UHF PD in transformers.