【摘要】 为了减少现场局放测试中噪声及干扰的影响,介绍了宽带在线测量局部放电的方法。传统的IEC检测法和近年来的特高频检测法回避了干扰频带,也回避了放电脉冲的主要能量频带,难以记录完整脉冲波形,缺乏足够的信息来区分各种信号和噪声。而宽带测试方法频带较宽,可以记录整个局部放电脉冲波形,并在此基础上提取基于波形的特征信息,进而可将信号分离分类,比针对单一放电的识别效果好得多。为此以高压电缆上多种放电模式与和噪声混合信号为例,从中获取波形中足够的信息,进而将信号分离为不同的放电类型,如内部放电、背景噪声等,从而提高了识别的可能性与准确性。对现场局放测试与诊断而言,如果能够广泛运用该方法,将能提高现场排除噪声与干扰、诊断绝缘特性的准确性。更多还原

【Abstract】 A wide-band online partial discharge(PD)detection method is discussed to minimize the influence of the noise and interferences during the course of measurement and diagnosis followed.The traditional IEC pulse current detection method and the recently developed ultra high frequency detection method have limited their bandwidth to avoid the abundant ambient noise and interference,and loss of the information of the PD signals as well.The methods can not record the entire discharge waveforms of the PD current pulses,causing a fundamental lack of information to neither differentiate various signals and noises,nor distinguish various PD or interference patterns.The wide band detection method covers a bandwidth wide enough to record the entire partial discharge pulse waveforms.Based on the features of their pulse waveforms,such signals can be separated and recognized in a’clean’condition.An experiment employing such method on a 110kV cable with several discharge patterns and onsite noises is presented.The analysis shows that,with sufficient information of the entire waveform,those discharge patterns can be separated,and each of the’clean and pure’sub-patterns,such as the internal discharge and background noises can be isolated and well recognized.For field PD detection and diagnosis,the method would increase the ability to remove the impact of onsite noises and interferences,as well as the ability to diagnose the insulation condition based on the PD information.更多还原