摘要
为研究变压器局部放电测量的频带问题,通过模拟试验测量了放电信号。信号功率谱密度的分析表明, 典型窄脉冲放电信号能量主要集中在≤10MHz。测量系统带宽对放电信号幅值影响的研究表明,带宽≥12MHz后对信号幅值无明显改善,带宽可根据需要选为8～20MHz。
During the detection of partial discharge (PD) in transformer, it is necessary to select a proper frequency bandwidth of measurement for improving quality of the detection. A suggested frequency range of PD measurement is presented in this paper. At first, an imitating experiment with typical narrow PD is carried out in an actual transformer. The imitative current of PD pulse is input into the winding at different positions, and response at measuring-terminal is detected so that the PD signal can be gained. Then the energy region of PD in transformer is studied by analyzing the power spectral density of the signal. It is found that the energy descends significantly over 10 MHz in frequency domain. It indicates that the energy of PD centralizes in the frequency below 10 MHz. Finally, the effect of frequency bandwidth of measuring device on the amplitude of PD signal is studied. The PD signal is processed by a series of low-pass digital filters, so that influence of different measuring devices on signal can be simulated. It shows that the amplitude of the processed signal has less relationship with the filter when its upper frequency is over 12 MHz. It is presented that the band width of PD measuring device can be 8 to 20 MHz.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2005年第1期45-46,共2页
High Voltage Engineering
关键词
局部放电
脉冲电流法
频带
partial discharge
pulse current method
freq uency band
