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A ground fault location method for power overhead lines

A technology of fault distance measurement and power overhead, which is applied to the fault location, fault detection according to the conductor type, and electrical measurement. It can solve the problems of low fault location efficiency, complicated operation process, and difficult application, so as to improve the quality of power supply and shorten the search time. the effect of time

Active Publication Date: 2020-09-18
淄博威特电气有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although there are relatively mature line selection devices and point-fixing devices on the market, the fault location operation needs to segment the fault circuit and mount the detection sensor on the climbing pole. The operation process is relatively complicated and the fault point-pointing efficiency is low.
Due to the existence of multi-level branches in the power distribution network and the installation of a large number of distribution transformers on the circuit, it is difficult to apply the resistance method, traveling wave method and other technologies widely used in the power transmission circuit to the power distribution circuit.

Method used

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  • A ground fault location method for power overhead lines
  • A ground fault location method for power overhead lines
  • A ground fault location method for power overhead lines

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] When a ground fault occurs in the overhead line, the microcomputer relay protection device in the prior art can determine which of the three phases A, B, and C the fault phase is, but cannot locate the position or approximate position of the ground fault point. The method is based on known fault phases and non-fault phases of the ground fault line, uses impedance method to calculate, and then calculates the position of the ground fault point.

[0033] A method for distance measurement of an overhead wire grounding fault disclosed by the present invention comprises the following steps:

[0034] a. Short-circuit the faulty phase of the ground fault line with the head end of any non-faulty phase in the faulty line through the sampling circuit. The sampling circuit is first and second sampling resistors R01 and R02 connected in series. The connection point of the first and second sampling resistors R01 and R02 is formed as a short-circuit point A at the head end.

[0035]...

Embodiment 2

[0080] In step c based on embodiment one:

[0081] Also collect the voltage between the sampling circuit and the connection point of the faulty phase and the first short-circuit point A, as well as the voltage between the sampling circuit and the non-faulty connection point and the first-end short-circuit point A, to avoid the connection point between the sampling circuit and the faulty phase. The impact of the contact resistance and the partial voltage generated by the contact resistance of the connection point between the sampling circuit and the non-fault phase on the measurement results.

[0082] Such as Figure 4 As shown, in the first measurement, the phasor value of the collected signal source output voltage is The collected phasor values ​​of the voltages of the first and second sampling resistors R01 and R02 The phasor value of the voltage between the first sampling resistor R01 and the connection point of the non-fault phase phase and the short-circuit point A of...

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Abstract

The invention discloses a distance measuring method for grounding faults of electric power overhead lines, which belongs to the field of relay protection in electric power engineering, and comprises the following steps: a. passing the first end of a faulty phase of a grounding fault line and any non-faulty phase through a sampling circuit Perform short-circuiting to form the first-end short-circuit point A, and short-circuit the faulty phase with the end of the above-mentioned non-faulty phase; b. Inject a high-voltage low-frequency AC power signal between the first-end short-circuit point A and the grounding system, and collect the sampling circuit Electrical parameters; c. Change the parameters of the sampling circuit and then inject the high-voltage low-frequency AC power signal again, and collect the electrical parameters of the sampling circuit; d. Use the electrical parameters collected in b and c to list the equations to calculate the ground fault point before and after The resistance of the transmission line, and the location of the fault point is calculated according to the total length of the transmission line.

Description

technical field [0001] The invention relates to the technical field of distance measurement for faults in electric power systems, in particular to a method for distance measurement for grounding faults of electric power overhead lines. Background technique [0002] my country's 6kV ~ 35kV distribution network widely adopts the neutral point non-effective grounding method, also known as the small current grounding system. Hour. The disadvantage is that when a single-phase ground fault occurs, it is impossible to confirm which circuit the problem lies in, and it is impossible to quickly find the fault point. Since the phase voltage rise caused by this kind of fault poses a great threat to the insulation performance of the system, the fault circuit must be quickly detected and eliminated. Although there are relatively mature line selection devices and point-fixing devices on the market, the fault location operation needs to segment the fault circuit, mount the detection sensor...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01R31/08G01R31/52G01R31/58
CPCG01R31/085G01R31/50
Inventor 陈宗军李桂义李义明朱海生张华平岳彩儒向洪彬赵刚袁超
Owner 淄博威特电气有限公司