CN105044579A

CN105044579A - Measurement method for distributed partial discharge

Info

Publication number: CN105044579A
Application number: CN201510298615.1A
Authority: CN
Inventors: 汪波; 肖传强; 张凤喜; 刘海博; 秦旭东; 王军合; 左贤锟; 李志刚
Original assignee: BEIJING SINDIA INSTRUMENTS Co Ltd
Current assignee: BEIJING SINDIA INSTRUMENTS Co Ltd
Priority date: 2015-06-05
Filing date: 2015-06-05
Publication date: 2015-11-11

Abstract

The invention relates to a measurement method for distributed partial discharge. The measurement method comprises the following steps that 1) multiple three-channel partial discharge measuring instruments detect multiple adjacent three-phase cable joints, which belong to a group of cable joints, respectively; 2) partial discharge measuring software obtains the phase spectrogram (Q-phi diagram) in the group of cable joints; 3) the attenuation degrees of the discharge amount (Qiec) of al l the cable joints of the group in the Q-phi diagram are compared to determine a suspected cable of partial discharge, and if there is no suspected cable joint, a next group of cable joints is tested; and 4) partial discharge platform software monitors the suspected cable joint online for more then 24 hours, and a stored Q-phi trend diagram is compared to determine whether partial discharge occurs in the cable, and if not, measurement for the next group of cable joints starts. Compared with the prior art, the detection accuracy for cable partial discharge is high, and offline analysis on the cable partial discharge is realized.

Description

The measuring method of distributed shelf depreciation

Technical field

The present invention relates to a kind of cable local discharge detection technique, particularly relate to a kind of measuring method of cable distribution shelf depreciation.

Background technology

Along with the develop rapidly of electric power networks and electricity consumption cause, new requirement be it is also proposed to the safe operation of electric power networks and electricity consumption; Specific to cable, its safe operation and security maintenance also inevitably more and more pay attention to by electric system.The main cause of cable fault is deterioration and the actual effect of insulating property, and shelf depreciation causes the main cause of insulating performance of cable deterioration.Mainly adopt single measurement of partial discharge instrument to detect individual cable joint in short-term at present and determine whether shelf depreciation, the local discharge signal which measures is likely the local discharge signal that other cable splice transmits, its detection accuracy is poor, easily judges by accident.

Summary of the invention

The invention provides a kind of measuring method of distributed shelf depreciation, for solving the problem of existing cable Partial Discharge Detection poor accuracy.

The invention provides a kind of measuring method of distributed shelf depreciation, comprise the following steps:

1) 1 triple channel measurement of partial discharge instrument independent detection, 1 threephase cable joint, multiple triple channel measurement of partial discharge instrument detects multiple adjacent cable splice by Fiber connection simultaneously, and described multiple adjacent cable splice is expressed as one group of cable splice;

2) the phase place spectrogram (Q-φ schemes) that Survey Software obtains A/B/C three-phase in described one group of cable splice is put in office;

3) the Q-φ investigating described one group of cable splice schemes, and judges whether shelf depreciation occurs.If there is shelf depreciation, judge which cable finds doubtful shelf depreciation by the attenuation degree of discharge capacity (Qiec) in each cable splice Q-φ figure of contrast, if there is no shelf depreciation, test next group cable splice;

4) platform software carries out being greater than 24 hours on-line monitoring for the cable splice of doubtful generation shelf depreciation is put in office, stores a large amount of history Q-φ and schemes, and determines whether cable shelf depreciation occurs by contrast Q-φ trend map.If get rid of the cable splice of doubtful generation shelf depreciation, from step 1) restart to measure next group cable splice.

Compared with prior art, the present invention adopts multiple triple channel office to put measuring instrument iteration and measures the cable splice that many group cable splices comprehensively determine to occur shelf depreciation, improves the accuracy of cable local discharge diagnosis, and effect stability is reliable, be beneficial to and apply.

Accompanying drawing explanation

Accompanying drawing 1 is block diagram of the present invention;

In figure, each label is: 1, A phase cable; 2, B phase cable; 3, C phase cable; 4, No. 1 cable splice; 5, No. 2 cable splices; 6, No. 3 cable splices; 7, No. 4 cable splices; 8, high frequency CT sensor; 9, measuring instrument is put in No. 1 triple channel office; 10, measuring instrument is put in No. 2 triple channel offices; 11, measuring instrument is put in No. 3 triple channel offices; 12, multimode optical fiber; 13, communication unit; 14, office puts Survey Software drawn game and puts platform software.

Accompanying drawing 2 is schematic flow sheets of the present invention;

Embodiment

In conjunction with Figure of description, example of the present invention is described in further detail.

The measuring method of distributed shelf depreciation: multiple triple channel office puts measuring instrument and organizes cable splice by iteration measurement more, the decay intensity that Qiec in interior each cable splice Q-φ figure is often organized in contrast determines the cable splice that shelf depreciation most possibly occurs, finally carry out the cable splice of the doubtful generation shelf depreciation of on-line monitoring being greater than 24 hours and store history Q-φ figure and make a definite diagnosis in all directions, substantially increasing the accuracy that cable local discharge detects.Performing step is as follows:

1) measuring instrument 9 is put in No. 1 triple channel office, measuring instrument 10 is put in No. 2 triple channel offices, No. 3 triple channel offices put measuring instrument 11 and gather A phase cable 1 in No. 1 cable splice 4 and No. 2 cable splices 5 and No. 3 cable splices 6 respectively by high frequency CT sensor 8, B phase cable 2, the local discharge signal of C phase cable 3, wherein defining No. 1 cable splice 4 and No. 2 cable splices 5 and No. 3 cable splices 6 is one group of cable splice.

2) communication unit 13 puts measuring instrument 9,10 by multimode optical fiber 12 and each triple channel office, and 11 carry out data transmission, and communication unit 13 starts whole triple channel offices simultaneously and puts measuring instrument 9,10, and 11 carry out local discharge signal collection.

3) office puts Survey Software 14 and obtains each cable splice 4,5, A/B/C threephase cable 1,2 in 6, and the Q-φ of 3 schemes, and investigates these Q-φ figure and has determined whether shelf depreciation.If there is shelf depreciation, judge which cable finds doubtful shelf depreciation by the attenuation degree contrasting Qiec in each cable splice Q-φ figure, if there is no shelf depreciation, test next group cable splice, such as No. 2 cable splices 5 and No. 3 cable splices 6 and No. 4 cable splices 7 are defined as lower group of cable splice, repeat step 1), 2), 3) until find the doubtful shelf depreciation in certain group cable splice.

4) for the cable splice of doubtful generation shelf depreciation, such as suspect that No. 2 cable splices 5 have shelf depreciation, then put with office the on-line monitoring that platform software 14 is greater than 24 hours to No. 2 cable splices 5, store a large amount of Q-φ to scheme, survey crew is by checking that these history Q-φ figure determines whether the electric discharge of generation office still exists other interference to No. 2 cable splices 5 further.If eliminate the cable splice of doubtful generation shelf depreciation, re-start step 1), 2), 3) until find certain group cable splice in shelf depreciation.

Claims

1. the measuring method of distributed shelf depreciation, is characterized in that, comprises the following steps;

1) 1 triple channel measurement of partial discharge instrument independent detection, 1 threephase cable joint, multiple triple channel measurement of partial discharge instrument detects multiple adjacent threephase cable joint by Fiber connection simultaneously, and described multiple adjacent threephase cable joint is expressed as one group of cable splice;

3) the Q-φ investigating described one group of cable splice schemes, judge whether shelf depreciation occurs, if there is shelf depreciation, judge which cable finds doubtful shelf depreciation by the attenuation degree of discharge capacity (Qiec) in each cable splice Q-φ figure of contrast, if there is no shelf depreciation, test next group cable splice;

4) platform software carries out being greater than 24 hours on-line monitoring for the cable splice of doubtful generation shelf depreciation is put in office, store a large amount of history Q-φ to scheme, determine whether cable shelf depreciation occurs, if get rid of the cable splice of doubtful generation shelf depreciation, from step 1 by contrast Q-φ trend map) restart to measure next group cable splice.

2. the measuring method of distributed shelf depreciation according to claim 1, it is characterized in that, more than 2 triple channel measurement of partial discharge instrument are adopted to measure more than 2 adjacent cable splices, the number often organizing cable splice is equal, and the cable splice number in a group is identical with the number of triple channel measurement of partial discharge instrument.

3. the measuring method of the distributed shelf depreciation according to claim 1 and claim 2, it is characterized in that, each triple channel measurement of partial discharge instrument gathers the local discharge signal in each cable splice on A, B, C threephase cable ground wire by high frequency CT, and each triple channel measurement of partial discharge instrument passes through Fiber connection.