CN2074506U - Double-functional discharge counter - Google Patents

Abstract

The utility model discloses a double-functional discharge counter used by matching with a lightning arrester. The voltage dependent resistor of the utility model is connected in series between a bridge rectifier and the lightning arrester, and the valve sheet of the double-functional discharge counter is made by adopting zinc oxide. Thusly, the utility model can accurately, safely and rapidly carry out measuring for conduction current magnitude of the running lightning arrester through counting and adopting the measuring method of an avometer connected in parallel, effectively monitoring the operating state of the lightning arrester and enhancing detecting safety on site and the running safety factor of an electric network. Thereby, the utility model overcomes the defect that detecting conduction current magnitude needs to be carried out by measuring with electrically connected in series or power failure when using a conventional counter.

Description

Double-functional discharge counter

The utility model belongs to record lightning arrester action frequency and can carry out the discharge counter of the conducting current value of live testing lightning arrester in service.It is particularly suitable for the supporting use of lightning arrester with 6～500 kilovolts of grades.

Whether normal in order to monitor operating lightning arrester work, adopt the supporting with it use of discharge counter usually.And monitor whether judge lightning arrester work by its record to the lightning arrester action frequency.As JS-8 type simple pointer discharge counter (Xi'an High-Voltage Electric Ceramics Factory's production) and the application number that generally uses at present be: 90212721.7 " two pointer discharge counter " etc. promptly belongs to this class device.Just can accurately judge but whether lightning arrester work whether normal can not be only moves by supporting with it counter.Also must measure its conducting current value, look its situation of change with the lightning arrester inner member of determining (back) in service whether have rotten, wear out, make moist, defective such as fracture or fault exist, so that take measures solution in time, guarantees electric power netting safe running.Avoid undesired or lost efficacy to high-voltage fence and use the frequent operation overvoltage workplace of lightning arrester to work the mischief because of lightning arrester work.The explosion accident of the lightning arrester that China happens occasionally in charging operation takes place because failing to find and in time change these out of order lightning arresters.But this detection is easier under routine or powering-off state, but it is really very difficult in operation of power networks lightning arrester to be carried out live testing.Therefore, each power supply department mainly detects it by regularly having a power failure its lightning arrester that puts into operation at present.But along with development and national economy, this method of detection can not adapt to requirement by having a power failure.In order to change this situation, the domestic test that has minority unit to carry out the lightning arrester live testing.Promptly adopt instrumentation at the scene the lightning arrester of band high-tension electricity in service to be carried out the test of conducting current value.The BFJ-1 type lightning arrester monitor of producing as Feidong, Anhui radio factory just belongs to this class instrumentation.This instrument utilizes a string high-tension resistive (about 800～1800 megaohms of resistance) in the resistance box to be parallel between the high-voltage terminal and earth connection of discharge counter with probe when measuring, the instrument with MF20 type avometer function that connects by the sample resistance of connecting with its high-tension resistive is converted into the purpose that electric current reaches test with it again.Accompanying drawing 1 is JS-8 type discharge counter electrical schematic, but because the inner overwhelming majority of these discharge counters is the carborundum valve block (non-linear resistor) that adopts, its resistance value very low (measure its resistance at this device into and out of line end and only be tens to more than 100 ohm).If adopt test in parallel (promptly by 2 tests of A, B), because the monitor internal resistance is big especially, therefore the conducting current value of measuring is extremely inaccurate; And to obtain measured value comparatively accurately, monitor is series to test in the circuit could obtains comparatively accurate data with regard to disconnecting connecting line (promptly disconnecting the A point) between discharge counter and the lightning arrester.Yet so just necessary live line working, and must artificially disconnect the interface between lightning arrester and the discharge counter, owing to be in the high-pressure work environment, this is not only dangerous, also easily cause simultaneously discharge counter high-pressure side insulated porcelain sleeve loosening, destroy the sealing of discharge counter, and bring future trouble to counter.In addition, its measurement point above earth potential is very high behind break, and this also brings difficulty to measurement.For above-mentioned reasons, thus this monitor fail at present to apply.At this situation, Xi'an High-Voltage Electric Ceramics Factory once produced a kind of JL type discharge counter that can be used for live line measurement conducting current value, the steel sole plate of the simple pointer JS-8 type discharge counter that this register will use at present changes the fiberglass base plate into, and inner total loop connecting line drawn is connected on the fiberglass base plate.With its short circuit, when detecting it is opened a way during operate as normal, this moment, discharge counter was in off-state, and measured conducting current value is also more accurate.But owing to need to disconnect the tie point of total loop at the scene when measuring equally, if be parallel to the test of A, B point, owing to electric current has I ₁, I ₂Two shunt, this moment, no matter monitor all can not all detect its conducting current with showing still.So register does not have the existing drawback of the above-mentioned monitor of radical change, thereby not popular with users yet, not seen widespread use.

The purpose of this utility model is to design a kind of special-purpose live testing instrument that do not need, do not need contact or counter total loop contact between the charged disconnection lightning arrester and discharge counter when operation of power networks yet, just can adopt common avometer (as MF7 type, 18 types, 20 types, 35 types etc.) safety, convenient, rapidly, the discharge counter exactly the conducting current value of lightning arrester in the positive charging operation measured.This counter is installed not only can be by counting but also can adopt method of testing to monitor the operating state of lightning arrester at any time exactly, improve the coefficient of safety of electrical network.

Solution of the present utility model is on the basis of JS-8 type discharge counter (being Fig. 1), and serial connection one piezo-resistance before bridge rectifier adopts to have the zinc oxide of high resistant characteristic as valve block simultaneously.Make full use of zinc oxide valve plate and piezo-resistance (also being zinc oxide) high resistant characteristic under normal conditions (when promptly adopting the avometer height to stop test, both resistances are equal to or greater than hundreds of kilo-ohms, and the dc resistance under its turnover conducting voltage converts is also more than tens of kilo-ohms) realize purpose of the present invention.Accompanying drawing 2 is the utility model electrical schematic, and 10 is (zinc oxide) piezo-resistance among the figure, and 7 is zinc oxide valve plate.In day-to-day operation, when lightning arrester BL moves, flow through valve block 7 and produce a residual voltage of impulse current at the valve block two ends, this residual voltage is simultaneously by piezo- resistance 10 and 8 chargings of 9 pairs of capacitors of bridge rectifier, and message register coil L is discharged with direct current, make counter action (every action is once promptly counted once), thereby realize the number of times of its record lightning arrester action.And in the time need judging that whether working properly lightning arrester is by the variation of testing its conducting current value, only need 2 in parallel can accurately tests of avometer and A, B.This is because when discharge counter of the present invention is serially connected with between lightning arrester and the earth point, although zinc oxide valve plate 7 is in high-impedance state with piezo-resistance 10, and valve block 7 and piezo-resistance 10 because its conducting current of high pressure effect also will be flowed through.When utilizing avometer to be parallel to A, B point when testing, because the D.C. resistance that the internal resistance of avometer is far smaller than valve block 7 and piezo-resistance 10 (for example: adopt MF20 type avometer to exchange 1.5mA retaining, sensitivity＜15mV, internal resistance and be about about 10 Ω.And valve block 7 and piezo-resistance 10 voltage under the 1mA direct current converts, its lowest resistance value also is not less than 200K Ω), therefore, the conducting current of former flow through valve block and piezo-resistance, all flow through through avometer this moment, thereby realize the purpose of live line measurement lightning arrester BL conducting current in parallel.The utility model is as long as suitably select the highest nominal voltage of piezo-resistance for use, its discharge counter the voltage at A, B two ends under the charged situation just can not surpass conducting current under the 300V(lightning arrester BL normal condition generally equal＜1mA), this also is easier to in-site measurement, and easily guarantees tester's safety.

Effect of the present utility model is, do not need special monitor for the detection of lightning arrester in service, also needn't be serially connected with on the circuit and measure, and reduced the danger of in-site measurement greatly.When test only needs can obtain accurately result with avometer two test pencils are in parallel with A, B respectively at 2 owing to be in operation; and the detection that needn't have a power failure; therefore; can make testing make a practice of, oversimplify; this provides convenience not only for on-the-spot the detection; help guaranteeing the fail safe of operation of power networks, but also can save the interruption duration when detecting, avoid the loss that brings to national economy thus simultaneously.

Accompanying drawing 1 is a JS-8 type discharge counter electrical schematic;

Fig. 2 is the utility model electrical schematic;

Fig. 3 is the utility model structural representation.

Among the figure: 1 is cloche, and 2 is single (two) pointer electromagnetic counting device, and 3 is ring flange, and 4 is base plate, and 5,6 is binding post, and 7 is zinc oxide valve plate, and 8 is capacitor, and 9 is bridge rectifier, and 10 is piezo-resistance, and 7a is the carborundum valve block.

Embodiment

Present embodiment for 500 kilovolts and matching used pair of pointer of following electric pressure lightning arrester, difunctional discharge counter be example:

Wherein cloche 1, ring flange 3, base plate 4, binding post 5,6.Capacitor 8, coil L etc., its structure, size and parameter are that 90212721.7 " two pointer discharge counter " and JS-8 type simple pointer " discharge counter " are identical with application number all; (two pointer) electromagnetism counting device 2 is then identical with above-mentioned " two pointer discharge counter ".And valve block 7 adopts zinc oxide to make, and diameter is φ 60mm, and thick is 5mm, the following voltage＜300V of its direct current 1mA, residual voltage＜1.3KV under the 10KA impulse current.Present embodiment square wave discharge capacity＞1KA, silicon dridge type rectifier 9 is 5A/1500V; Zinc-oxide piezoresistor 10 is the MY type, and nominal voltage is 180V, discharge capacity＞2KA.The utility model is serially connected with between lightning arrester and the ground wire by binding post 5,6 and uses, and its technical conditions meet GB GB---* * * * " lightning arrester discharge counter " (being about to the declaration standard of promulgation) specification requirement.

Claims (1)

1, a kind of difunctional discharge counter, it comprises base plate, ring flange, outer cover, valve block, capacitor, bridge rectifier, electromagnetism counting device, it is characterized in that between bridge rectifier and lightning arrester, also being in series with a Zinc-oxide piezoresistor, and its valve block also is a zinc oxide valve plate.

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