CN1154587A

CN1154587A - Capacitor type gas relay

Info

Publication number: CN1154587A
Application number: CN 96106480
Authority: CN
Inventors: 郑扶才
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-01-09
Filing date: 1996-08-14
Publication date: 1997-07-16

Abstract

The present invention relates to a gas relay made of self-body, capacitive gas sensor and amplifying-detecting circuit and used for oil-immersed power transformer. Its capacitive gas sensor consists of 2-8 conducting plates, in which four conducting plates called upper electrode plate are vertically placed in the upper portion of the self-body, and another four conducting plates called lower electrode plate are horizontally placed in the lower portion of the self-body. Those electrode plates are fixed on the self-body, its upper electrode plates are formed into two groups of capacitors, lower electrode plates also are formed into two groups of capacitors, and those capacitors are bridged, and the bridge output is passed through amplifying, A/D conversion and one-chip processor treatment to make network control.

Description

Capacitor type gas relay

The present invention relates to a kind of relay, particularly the oil immersed power transformer capacitor type gas relay.

Buchholz relay is the important devices of protection transformer safe operation; at present; the Buchholz relay that two kinds of structures are arranged; a kind of is two float-type; a kind of is the plate washer type; the two operation principle is basic identical; all be since transformer when operation the gas (comprising normal gas and failure gas) that produces when reaching a certain amount of; cause that the intrinsic pasta of relay descends; then the mercoid switch action that drives in float and the plate washer is reported to the police; though more than these two kinds of relay reliable operations, also have following problem:

1) report to the police (light gas action) be that gas occurs and be accumulated to certain amount (the mercoid switch action that just drives in sensing element float or the plate washer behind the 150ml～300ml) is reported to the police, this is that mechanical motion mechanism is limit, and the sensitivity of this relay is not high thus.

2) gas produces this time interval of reporting to the police and can't measure, and promptly the speed that produces of gas is not known, thus can't judge power transformer interior fault seriously whether.

3) also can report to the police for normal gas, can't judge and correct errors.

4) the Buchholz relay course of action can't detail record, can not consult.

That purpose of the present invention just provides is single between a kind of structure, highly sensitive, detect and can structure note the capacitor type gas relay of gas production process easily.

The object of the present invention is achieved like this, constitute the oil immersed power transformer capacitor type gas relay by a housing, capacitance type gas sensor and amplification detection circuit, its capacitance type gas sensor is made of the pole plate of a group or several groups of electric capacity two to eight conductive plates, as when adopting eight conductive plates to make the pole plate of capacitance type gas sensor, wherein four conductive plates that are called top crown are placed vertically above housing, four conductive plates that are called bottom crown lie in lower part of frame in addition, and last bottom crown is all fixed with housing; Form two group capacitors by top crown, bottom crown is also formed two group capacitors, the medium of capacitor is a transformer oil when transformer normally moves, when transformer has gas to produce, gas will enter the medium that top crown becomes electric capacity in the top crown, four capacitors are connected into bridge circuit, output is handled by amplification detection circuit, amplification detection circuit of the present invention is by amplifier, A/D converter, Single Chip Microcomputer (SCM) system is formed, its course of work is: be full of transformer oil in the relay housing chamber when transformer moves, four capacitors that be made up of top crown and bottom crown this moment are certain value, when gas occurs, because capacitor gas enters in the top crown, bridge circuit will be exported by vicissitudinous signal, because of the medium coefficient of transformer oil is the several times of gas medium coefficient, therefore the output signal of bridge circuit will be clearly, tolerance is many more, oil level descends many more, electric capacitance change is obvious more, by measurement to the bridge circuit signal, just to the cubing of gas flow, and this measurement is the continuous measurement to gas flow, and handle by Single Chip Microcomputer (SCM) system, therefore the variable quantity of gas will be shown easily, record, and report to the police by the parameter of prior setting, explain until jumping and to cut off connecting of transformer and electrical network, so the present invention is actually an intelligent Buchholz relay.

Obviously, advantage of the present invention is very tangible, because when gas enters in two electric capacity being made up of top crown, changes in capacitance is the variation of a continuous quantity, these two electric capacity constitute bridge circuit with two electric capacity that bottom crown is formed again, and bridge circuit will produce a very significantly signal variation to very little changes in capacitance, therefore say that the present invention is highly sensitive, again because sort signal is through amplifying, the A/D conversion is handled by single-chip microcomputer again, because single-chip microcomputer has clocking capability, when the transformer internal gas is constantly emitted, bridge circuit will be exported a relative continually varying signal, and this signal is recorded by the single-chip microcomputer meter, can understand the speed that produces gas as calculated, root a tree name speed size can judge that gas is normal gas or failure gas, power transformer interior fault seriously whether.

The present invention will be further described below in conjunction with accompanying drawing:

The structural representation of the present invention that Fig. 1 is made up of eight conductive plates.

Fig. 2 is bridge circuit of the present invention and signal processing block diagram.

Fig. 3 is the A-A direction cut-away view of Fig. 1.

The top of Fig. 3, Fig. 1 middle shell 1 vertically is fixed with the top crown 6 that four

conductive plates

2,3,4,5 that are parallel to each other are formed, and conductive plate 2,3 constitutes two battery lead plates of capacitor C1, and

conductive plate

4,5 constitutes two battery lead plates of capacitor C2; The lower horizontal of housing 1 is fixed with the bottom crown 11 that four conductive plates that are parallel to each other 7,8,9,10 are formed, and conductive plate 7,8 constitutes two battery lead plates of capacitor C3, and conductive plate 9,10 constitutes two battery lead plates of capacitor C4.

Capacitor C 1, C2, C4, C3, C1 link to each other successively among Fig. 2, and the tie point a of capacitor C 1 and C3 and the tie point b of capacitor C 2 and C4 meet power supply U as the power supply input of bridge circuit _s, the tie point e of capacitor C 1 and C2 and the tie point d of capacitor C 3 and C4 are as the output of bridge circuit, and the output of bridge circuit is handled through amplification, A/D conversion and single-chip microcomputer and is constituted oil immersed power transformer Buchholz relay of the present invention.Because a lot of Fig. 2 of method that the bridge circuit input signal is handled only provide its block diagram.

When in housing, two conductive plates being installed, differently with the structure of eight formations be, the top that two conductive plates only vertically are fixed on housing constitutes one group of electric capacity, this electric capacity inserts in the resistance-capacitance oscillator, the frequency of oscillator is determined by the electric capacity in resistance and the housing, the frequency output of this oscillator directly inserts the system that single-chip microcomputer is formed, the frequency change of single-chip microcomputer root a tree name oscillator is understood the speed that produces gas, root a tree name speed size, judge that gas is normal gas or failure gas, power transformer interior fault seriously whether.

Claims

1. one kind by housing, the capacitor type gas relay that places the sensing element in the housing to form, it is characterized in that: its sensing element is the pole plate that is made of gas sensor electric capacity two to eight conductive plates, the medium of capacitor is that the gas of transformer oil or transformer generation or the gas of transformer oil and transformer generation all have, and the signal of capacitance type gas sensor is handled and controlled through A/D conversion, Single Chip Microcomputer (SCM) system.

2. the described capacitor type gas relay of root a tree name claim 1, it is characterized in that: when adopting eight to do capacitance type gas sensor, wherein four conductive plates that are called top crown (6) are placed the top in housing (1) vertically, four conductive plates are called the bottom that bottom crown (11) lies in housing (1) in addition, and top crown (6) and bottom crown (11) are all fixing with housing (1).

3. root a tree name claim 1 and 2 described capacitor type gas relays, it is characterized in that said capacitance type gas sensor, its conductive plate (2) and (3) constitute two battery lead plates of capacitor C1, and conductive plate (4) and (5) constitute two battery lead plates of capacitor C2; Conductive plate (7) and (8) constitute two battery lead plates of capacitor C3, and conductive plate (9) and (10) constitute two battery lead plates of capacitor C4; Capacitor C 1, C2, C4, C3, C1 link to each other successively and constitute bridge circuit; The tie point a of capacitor C 1 and C3 and the tie point b of capacitor C 2 and C4 meet power supply U as the power supply input of bridge circuit _s, the tie point e of capacitor C 1 and C2 and the tie point d of capacitor C 3 and C4 are as the output of bridge circuit.