Fault indicator and fault detecting method

Abstract

The invention relates to a fault indicator and a method. The fault indicator comprises a sampling circuit, a filtering circuit and a detecting circuit, wherein the sampling circuit, the filtering circuit and the detecting circuit are used for collecting, filtering and detecting two types of frequency signals of the circuits respectively. The fault indicator further comprises a calculating unit which calculates a double-frequency measurement current ratio according to a detection output result, a judging unit which judges whether the next stage of the fault indicator has single-phase grounding faults or not according to the calculation result, and a communication module which transmits the judgment result and the calculation result to a monitoring system. By sampling two frequencies, calculating the signal ratio of the frequencies and judging whether single-phase grounding faults exist or not, on-site judgment can be achieved, accuracy can be improved, fault points can be directly reported, uploaded data is small, accuracy is high, a fault positioning and detecting method of a fault point direct reporting system is simpler, and the fault points are effectively positioned.

Description

technical field [0001] The invention relates to a fault indicator and a fault detection method. Background technique [0002] At present, the fault indicator is to comprehensively judge whether there is a single-phase ground fault through the synthetic zero-sequence current data reported to the monitoring system. Using this method, the system structure is complicated. And because three synthetic zero-sequence currents are required, and these three synthetic zero-sequence currents may not be synchronized, resulting in errors, and the amount of signal data collected is relatively large, and the GPRS transmission method has a relatively high probability of disconnection, which will Data loss is caused, and the reported information is inaccurate. In addition, the alarm cannot give an alarm on the spot, it needs to be judged by the monitoring system, and then the monitoring system sends out an alarm signal. Contents of the invention [0003] The technical problem to be solved...

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Problems solved by technology

[0002] At present, the fault indicator comprehensively judges whether there is a single-phase ground fault through the synthetic zero-sequence current data reported to the monitoring system. Using this method, the system structure is complicated

And because three synthetic zero-sequence currents are required, and these three synthetic zero-sequence currents may not be synchronized, resulting in errors, and the amount of signal data collected is relatively large, and the GPRS transmission method has a relatively high probability of disconnection, which will Data loss, resulting in inaccurate reported information

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