Small-current grounding system single-phase grounding fault section locating method
A single-phase grounding fault, low-current grounding technology, applied in the fault location and other directions, can solve the problems of difficult section location, complex distribution network structure, small fault point current, etc., to achieve anti-interference performance and high accuracy, programming Simple, Reliable Effects
Inactive Publication Date: 2015-12-02
NORTH CHINA ELECTRIC POWER UNIV (BAODING) +1
View PDF8 Cites 10 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
The line selection technology for single-phase-to-ground faults in distribution networks has always been a research hotspot. However, due to the increasingly complex structure of the distribution network and the small current at fault points, the problem of fast and accurate line selection for single-phase-to-ground faults has not been satisfactorily resolved. Section positioning more difficult
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0025] In the small current grounding system, the direction of the busbar flowing to the line is the positive direction of the current reference. For the neutral point ungrounded system, when a single-phase ground fault occurs in the system, the zero-sequence current of the non-faulted line leads the zero-sequence voltage by an angle, and the angle is less than 90 degrees, such as figure 1 As shown; the zero-sequence current of the fault line lags the zero-sequence voltage by an angle, and the angle is greater than 90 degrees, such as figure 2 shown. For the system where the neutral point is grounded through the arc-suppression coil, when a single-phase ground fault occurs in the system, due to the compensation of the arc-suppression coil, the zero-sequence current of the fault line leads the zero-sequence voltage by an angle, and t...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention discloses a small-current grounding system single-phase grounding fault section locating method. The method includes the following steps that: feeder terminal devices are set according to the phase relationships of zero-sequence current and zero-sequence voltage which pass through lines and based on a characteristic that fault lines and non-fault lines have different zero-sequence current and voltage phase relationships when a single-phase grounding fault occurs on a small-current grounding system, and the state digit numerical values of the feeder terminal devices are uploaded to a main station; the main station performs logical operation according to the state digit numerical values of the feeder terminal devices; and judgment and selection of fault sections can be completed through detecting the state digit numerical values of feeder terminal devices in the fault lines. The method of the invention has the advantages of simple programming, easiness in realization and suitability for an operating mode in which a neutral point is not grounded and an operating mode in which a neutral point is grounded through an arc extinction coil.
Description
technical field [0001] The invention relates to the technical field of power system fault detection, in particular to a method for locating fault sections when single-phase grounding occurs in a small current grounding system. Background technique [0002] At present, most of my country's 35kV and below distribution networks adopt the neutral point non-effectively grounded operation mode, that is, the neutral point is not grounded or grounded through the arc suppression coil. For these two wiring methods, when a single-phase ground fault occurs in the system, due to the small fault current value of the ground point, the power system regulations can allow the system to operate with a fault for 1~2h to improve the reliability of power supply. However, since the non-faulty phase voltage will rise to the line voltage under this operation mode, long-term operation will endanger the insulation level of the line, and may expand into a phase-to-phase short circuit, which will affect...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/08
Inventor 李燕青姜建谢红玲宋乐王凯杨惠岚郑伟彦王川李洋沈蕴华
Owner NORTH CHINA ELECTRIC POWER UNIV (BAODING)