A method for determining single-phase grounding fault in small current grounding system

A single-phase grounding fault, small current grounding technology, applied in the fault location, detecting faults according to conductor types, measuring electricity and other directions, can solve the problem of low fault false alarm and omission rate of fault indicators, and solve the problem of fault false alarm and omission. The effect of high reporting rate, improving accuracy, and improving the level of feeder automation

Active Publication Date: 2019-04-16
WUHAN ZHONGYUAN ELECTRONICS INFORMATION
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Problems solved by technology

[0004] The purpose of the present invention is to provide a method for judging single-phase ground faults in small current grounding systems, aiming to solve the problem of low fault false positives and negative negative rates of existing fault indicators

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  • A method for determining single-phase grounding fault in small current grounding system
  • A method for determining single-phase grounding fault in small current grounding system
  • A method for determining single-phase grounding fault in small current grounding system

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[0033] In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

[0034] The application principle of the present invention will be described in detail below in conjunction with the accompanying drawings.

[0035] Such as figure 1 As shown, the method for judging a single-phase ground fault in a small current grounding system provided by an embodiment of the present invention includes the following steps:

[0036] S101: Start the single-phase ground fault judgment according to the sudden change of electric field intensity and phase current, and use the shape gradient method to accurately determine the starting time of the fault, so as to realize the accurate synchronization of the three-...

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Abstract

The invention discloses a method for judging a single-phase grounding fault in a small-current grounding system. The judgment of a single-phase grounding fault is started according to a sudden change in electric field intensity and a sudden change in phase current. Accurate synchronization; filter the transient current signal to determine the duration of the transient process, use the autocorrelation method to calculate the characteristic frequency of the transient current; then locate the ground fault according to the correlation between the fault phase and the non-fault phase transient current, and realize Single-phase ground fault detection in small current grounding systems applied to fault indicators. The present invention is not affected by the operation mode, grounding location, grounding resistance, etc. Compared with the threshold value comparison method adopted by the current fault indicator, it does not require on-site setting and debugging, can greatly improve the accuracy of fault discrimination, and solve the problem of false alarms in existing fault indicators The problem of low false negative rate greatly improves the automation level of the feeder.

Description

technical field [0001] The invention belongs to the technical field of fault location of power system distribution network, and in particular relates to a single-phase ground fault judgment method of a small current grounding system. Background technique [0002] Most distribution networks with a voltage level of 66kV and below in my country adopt the non-effective neutral point grounding method, and this system is often called a small current grounding system. In this mode, when a single-phase grounding fault occurs in the power grid, the fault current is small (especially the grounding system through the arc suppressing coil), although the regulations allow continuous operation for 1 to 2 hours, the voltage of the non-grounded phase after the fault becomes the line voltage, which is harmful to the system. Insulation brings hidden dangers and threats. It is necessary to cut off the faulty line as soon as possible to avoid two-point grounding and short-circuit accidents. Fer...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01R31/02G01R31/08
CPCG01R31/086G01R31/088G01R31/50
Inventor 张文魁王大兴张林桥张恒舫李欣
Owner WUHAN ZHONGYUAN ELECTRONICS INFORMATION
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