CN2476033Y - Device for monitoring circuit breaker contact head electric service life - Google Patents
Device for monitoring circuit breaker contact head electric service life Download PDFInfo
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- CN2476033Y CN2476033Y CN 01239795 CN01239795U CN2476033Y CN 2476033 Y CN2476033 Y CN 2476033Y CN 01239795 CN01239795 CN 01239795 CN 01239795 U CN01239795 U CN 01239795U CN 2476033 Y CN2476033 Y CN 2476033Y
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Abstract
The utility model provides a monitoring device of electrical endurance for a breaker contact, comprising an upper computer and a lower computer. The upper computer is an industrial control computer and the lower computer consists of a plurality of sampling plates. The upper computer is connected with the lower computer by a dual-port RAM, namely, the address buses and the date buses of the upper computer and the lower computer are both connected on the dual-port RAM. Each signal sampling plate comprises a sampling resistance R2 of the signal collection circuit connected with a multiplexer by a protection circuit consisting of C1 and D1-D4, a RF follower is connected to the mutiplexer, the output of the RF follow is connected with an accurate rectifying circuit, the output of the accurate rectifying circuit is connected with an A/D transformer, the output of the A/D transformer is connected with a CPU, and the address bus and the date bus of the CPU is connected with a dual-port RAM.
Description
The utility model relates to a kind of contact of breaker electrical endurance monitoring apparatus, belongs to the on-line monitoring to circuit breaker electrical endurance, is the monitoring device of circuit-breaker status overhaul service.
Maintenance is of great importance and very big economic benefit to circuit-breaker status to implement the circuit breaker electrical endurance on-line monitoring, but the electric life of isolating switch is a very complicated problems.Development of modernization is more and more higher to the requirement of power supply reliability and power supply quality, modern large-scale power grid be by number huge send out, send, fail, big system that controller switching equipment is formed by connecting, the reliability of these power equipments and performance directly determine the reliability and the power supply quality of powering.We know that not only quantity is many but also extremely important at these device interrupt road devices, they are bearing the task of cut-offfing of fault current and load current, and the cut-offfing each time the serviceable life that has all correspondingly reduced isolating switch of isolating switch, reduced the break performance of isolating switch, after using certain hour, if can not in time find and get rid of the latent fault of isolating switch, cause catastrophic consequence for electric system and user with regard to can not normally cut-offfing.At this situation, have both at home and abroad and much deliver about the article of circuit breaker electrical endurance, a lot of view and some solutions about circuit breaker electrical endurance have been proposed.Domestic many R﹠D institutions and manufacturer split and make a kind of device of accumulative total dropout current and accumulative total open and close times that can write down so that scientifically the time between overhauls(TBO) of definite isolating switch has been paid very big effort over past ten years, developed multiple instrument, at the beginning of one nine eight two, Suzhou switchgear plant and Electric Power Research Institute of Ministry of Water Resources and Power Industry have developed DJY-1 type short-circuit current registering instrument jointly, it is divided into nine etc. by size with electric current, presses current class record accumulative total open and close times; In 1993, the KG type isolating switch dropout current registering instrument of the common development of space center of the Chinese Academy of Sciences and Beijing friendly industrial corporation of China of All-China Federation of Returned Overseas Chinese can be read each phase total current and each switch off time and nearest 100 times current value that isolating switch has cut-off at any time; At present, according to the research and the test of home and abroad, we think: from the angle of accumulative total electrical wear, in other condition one regularly, the electrical wear of isolating switch depends mainly on arc energy, with the accumulative total dropout current or the arc energy (I of record isolating switch
2T) electric life of reflection isolating switch has certain reason, still, the electrical wear of isolating switch not with arc energy or the proportional relation of dropout current, therefore with the accumulative total dropout current, totally open and close times waits the electric life science not that reflects isolating switch, and is also not directly perceived; In addition, the relation of the electrical wear of different isolating switchs and arc energy and accumulative total dropout current obviously has nothing in common with each other, and therefore, it is too simple that top recording method also seems.
The purpose of this utility model is under the prerequisite that does not influence relay protection of power system equipment; try every possible means from current signal itself; promptly ceaselessly gather every phase current signal; each half-wave is monitored; find average dropout current; calculate according to isolating switch dropout current and electrical wear relation curve parameter, realize the purpose of angles of science monitoring.
The technical solution of the utility model is: this contact of breaker electrical endurance monitoring apparatus comprises host computer and slave computer; host computer is an industrial computer; slave computer is made up of the polylith sampling plate; connect by dual port RAM between its host computer and the slave computer; the address and the data bus that are host computer are received on the dual port RAM; the address of slave computer and data bus are also received on the dual port RAM; every block signal sampling plate 1 comprises signal acquisition circuit 1-1; holding circuit 1-2; multi-way switch; penetrate a grade follower; precise rectification circuit; A/D converter and CPU; the sampled signal of the sample resistance R2 of signal acquisition circuit passes through by C1; the holding circuit that D1-D4 forms connects multi-way switch; the multi-way switch back connects penetrates a grade follower; the output of penetrating grade follower connects precise rectification circuit; the output termination A/D converter of precise rectification circuit; the output of A/D converter meets CPU, and address and the data bus of CPU are received on the dual port RAM.
Described contact of breaker electrical endurance monitoring apparatus; its signal acquisition circuit adopts punching secondary current mutual inductor; this mutual inductor is placed on the secondary line that connects protective relay of a CT of isolating switch, and sample resistance R2 links by shielded cable and mutual inductor secondary coil.
Described contact of breaker electrical endurance monitoring apparatus has resistance R 1 to be connected in parallel on the secondary of secondary CT in the punching secondary transformer circuit that its signal sample circuit adopts, and when sample resistance R2 got 40 Ω, the no-load voltage ratio of mutual inductor got 1000/1, and it is saturated that iron core is difficult for.
Described contact of breaker electrical endurance monitoring apparatus, its multi-way switch adopts digit chip 4067, and 16 signalling channels are arranged, and the number of sampling plate is by the number of the expansion slot of industrial computer.
The utility model has the advantages that;
1, we do not need to have selected the dual port RAM realization industrial computer (host computer) of call duration time and the mode of sampling plate (slave computer) shared memory, dual port RAM to host computer as extended memory (the direct map of internal memory), to slave computer (MCS96 Single Chip Microcomputer (SCM) system) then as data-carrier store.Data or communication cryptology that we will need to share are placed in the dual port RAM, then PC can carry out shared data and intercommunication mutually with single-chip microcomputer, dual port RAM is all regarded independently RAM district as to PC and Single Chip Microcomputer (SCM) system, and have two to overlap different separately address and bus, when same unit is visited on both sides, but the inner moderator automatic arbitration of IDT7132.The reliability and the accuracy of monitoring system have been guaranteed.
2; we have selected no-load voltage ratio for use is that 1000/1 iron core is difficult for saturated miniature straight-through current transformer; then the secondary current scope of secondary mutual inductor is 0～0.12A; secondary two resistance R 1 and the R2 of being connected at secondary CT; R1 is attempted by the secondary of secondary CT; and R2 is on sampling plate; R1 plays protection mutual inductor and shunting action; R2 is a sample resistance; because the distance from the secondary mutual inductor to microcomputer is longer; the shielded cable that we select for use same model and length to be more or less the same is chosen suitable R 1; R2 just can guarantee to enter the voltage signal of sampling plate within allowed band; not only guarantee certain precision, and do not influence the protective device of electric system.
3, because our sample frequency is very fast, about the about 60us of the sampling of each point and data processing time, therefore need to change sampling channel one time about about every 60us, and every road signal has nothing in common with each other, therefore just there are the speed problem of following of the corresponding and voltage of frequency, the reliability that our sampling plate circuit data is handled the circuit in signalling channel.It combines with A/D converter, makes sampling channel simple in structure, with low cost.
4, the main effect of slave computer (sampling plate) is exactly the dropout current that writes down each road, every sampling plate is monitored 16 road signals simultaneously, each half-sinusoid is gathered 10 points, be that every 1ms finishes the once touring sampling to 16 tunnel, an industrial computer generally can connect 10 sampling plates, the monitoring capacity is big, can satisfy the needs of general transformer station.
Below accompanying drawing is described:
Fig. 1 is the utility model overall circuit block diagram, Fig. 2 is the sample circuit schematic diagram, Fig. 3 is circuit theory diagrams of penetrating a grade follower, precise rectification circuit in the sampling plate, Fig. 4 is dual port RAM and cpu bus and PC bus connection layout, Fig. 5 is the slave computer main program flow chart, Fig. 6 is the interrupt service routine process flow diagram, and Fig. 7 is the upper computer software functional structure chart.L is that mutual inductor coil, T are that iron core, R1 are transformer circuit resistance among the figure; R2 is a sample resistance; R3 is a current-limiting resistance; C1 is a filter capacitor; D1-D4 is the holding circuit that stabilivolt and diode are formed, and M is a cable, and TL084 is the sample circuit integrated package; R4-R13 is a sample circuit resistance, and D4-D5 is the sample circuit diode.
Further specify embodiment of the present utility model below in conjunction with accompanying drawing:
One, signals collecting:
The signal is here taken from special miniature punching secondary mutual inductor; this mutual inductor is set on the secondary line that connects protective relay of a CT of isolating switch (seeing Fig. 1 and Fig. 2); so just big electric current is become little electric current; connect sample resistance again, current signal can be converted into-5V～+ voltage signal of 5V uses for sampling.Because the scope of the breaking current of isolating switch is very big; very little load current is arranged; very big short-circuit current is also arranged; our range of current that need sample is very wide in other words; when the electric current of setting the secondary side of a CT as us is 5A; the working current of isolating switch is the full load electric current; and general big short-circuit current can reach about 20 times of the full load electric current; therefore; the secondary side current scope of a CT can reach 0～120A; we have selected no-load voltage ratio for use is that 1000/1 iron core is difficult for saturated miniature straight-through current transformer; then the secondary current scope of secondary mutual inductor is 0～0.12A, and at secondary two resistance R 1 and the R2 of being connected to of secondary CT, R1 is attempted by the secondary of secondary CT; R1 plays protection mutual inductor and shunting action; R2 is a sample resistance, because the distance from the secondary mutual inductor to microcomputer is longer, and the shielded cable that we select for use same model and length to be more or less the same; choose suitable R 1; R2, the voltage signal that just can guarantee to enter sampling plate are within allowed band and the assurance certain precision.
Two, signal Processing:
Electric life for our monitoring breaker, we only are concerned about the effective value of the dropout current of isolating switch, and to simultaneity between each passage and no requirement (NR), we know by the front in addition, and our sampling algorithm is very simple, and the deadline of each sampling is very short, the sampling time of approximately whenever finishing any is about 60us, to 10 points of the per half ripple sampling of the current signal on every road, a sampling plate 16 road signals of can sampling need to prove here:
The multi-way switch back will connect the one-level emitter follower, this is because the conducting resistance of multi-way switch is generally 300 Ω～1k Ω, can there be partial pressure effects and the not enough situation of the load-carrying ability of multi-way switch when the back directly connects load, penetrate internal resistance and its load-carrying energy of raising that grade follower is offset multi-way switch so will connect one-level.
Because we are half-wave samplings, that the A/D conversion chip uses is AD574A, and (the sampled voltage scope is 0～10v), precise rectification circuit is arranged in the middle of therefore to select its one pole sample mode for use.
Because our sample frequency is very fast, about the about 60us of the sampling of each point and data processing time, therefore need to change sampling channel one time about about every 60us, and every road signal has nothing in common with each other, therefore the circuit in the signalling channel is just adopted and had the speed problem of following of the corresponding and voltage of frequency, and the about 150k of the frequency band of general amplifier, the about 0.7v/us of voltage follow speed, by analyzing, obviously can satisfy the demand.We adopt integrated sampling holder LF398 sampling hold circuit, keep electric capacity to get 1200pf.We adopt AD574A A/D converter, circuit as shown in Figure 4, AD574A has internal reference source, external power source is connected on the AD574A not directly as reference power supply, the A/D conversion is subjected to the influence of external power source and other circuit very little like this;
For our electrical endurance monitoring apparatus, the main effect of slave computer (sampling plate) is exactly the dropout current that writes down each road, every sampling plate is monitored 16 road signals simultaneously, each half-sinusoid is gathered 10 points, be that every 1ms finishes the once touring sampling to 16 tunnel, in observation process, preserve the maximum difference and the peak value of nearest 5 half-waves at any time, when the electric current of finding to have one tunnel is zero, promptly take out electric current and be the maximum difference and the peak value of 5 half-waves before zero, ask the dropout current value.
In order to improve the authenticity and the reliability of record dropout current value, we have adopted following several ways:
1: because when little electric current cut-offs, resolution with maximum difference method record dropout current is very low, for this reason, and to little load dropout current, we adopt peak value and dropout current corresponding relation to write down dropout current, and we adopt differential technique to come record to big dropout current.
2: when record dropout current value, the record value to each half-wave carries out reasonalbeness check earlier, rejects after the bad value, adopts the filtering algorithm of averaging to try to achieve when asking the dropout current value at last.Three, interface with communicate by letter
Our data acquisition and data rough handling are to be finished by many slave computers (MCS96 Single Chip Microcomputer (SCM) system), when detecting isolating switch and cut-off, arbitrary slave computer just need send the operation numbering of dropout current and isolating switch and information such as separate to host computer (IPC486 industrial computer), be responsible for the management of total system by host computer, the analysis that comprises interface, man-machine interface and data with handle or the like.Are how the data with slave computer sent to host computer? consider that each slave computer all will ceaselessly monitor each half-sinusoid of 16 road signals; and the mode that adopts serial communication or parallel communications will inevitably delay when transmitting data; this just will certainly influence the reliability and the accuracy of monitoring system; in addition; electric system the unsuccessful situation of isolating switch secondary reclosing occurs through regular meeting; generally from the first time separating brake to the time compole short (being generally 0.3 second) the second time separating brake; if once send the long meeting of the call duration time of data to have a strong impact on to secondary record that cut-offs; therefore from this point of view, we do not need to have selected the mode of passing through the dual port RAM data sharing of call duration time.
We adopt the mode that realizes industrial computer 486 and MCS96 single-chip microcomputer shared memory by dual port RAM (IDT7132), dual port RAM to host computer (PC grind China 486) as extended memory (the direct map of internal memory), to slave computer (MCS96 Single Chip Microcomputer (SCM) system) then as data-carrier store.Data or communication cryptology that we will need to share are placed in the dual port RAM, then PC can carry out shared data and intercommunication mutually with the MCS96 single-chip microcomputer, dual port RAM is all regarded independently RAM district as to PC and MCS96 Single Chip Microcomputer (SCM) system, and have two to overlap different separately address and bus, when same unit is visited on both sides, but the inner moderator automatic arbitration of IDT7132.
IDT7132 is that capacity is the dual port RAM of 2K byte, and IDT7132 has two cover buses to use for PC and MCS96 system respectively, and Fig. 5 is the wiring schematic diagram of IDT7132.
Following table is the table of comparisons of toggle switch position and decoding address:
| 2 | OFF | OFF | OFF | OFF | ON | ON | ON | ON |
| 3 | OFF | OFF | ON | ON | OFF | OFF | ON | ON |
| 4 | OFF | ON | OFF | ON | OFF | ON | OFF | ON |
| Offset address | 0000H ～07FH | 2000H ～27FFH | 4000H ～47FFH | 6000H ～67FFH | 8000H ～87FFH | A000 ～A7FFH | C000H ～C7FFH | E000H ～E7FFH |
As seen from table: as long as stir the position of toggle switch, can change the sector address or the offset address of extended memory, when we dial sector address into D000H, then can expand eight MCS96 Single Chip Microcomputer (SCM) system (being responsible for the slave computer of data acquisition and processing) altogether by the dual port RAM shared data.Four, upper computer software design:
As one circuit breaker electrical endurance is carried out the system of on-line monitoring, must at first set up an object, the isolating switch parameter relevant with electric life done the description of a system.Our total system could be set up the various various functional modules that this object is operated and served like this.By noted earlier, we know, the relative electrical wear relative electric life current when obtaining isolating switch and cut-offfing at every turn with isolating switch, must know that this isolating switch is few oil, SF6 or vacuum, because the model of corresponding every kind of its electrical wear of isolating switch is different, also to know this isolating switch rated short circuit drop-out current, allow to cut-off full appearance number of times and electric life initial value; Here our initial value of circuit breaker electrical endurance slightly perform an analysis, because when this cover system drops into substation operation, the miscellaneous equipment of transformer station is not just to put into operation, so the relative electric life initial value of isolating switch is not 100%, according to analysis, this initial value is historical relevant with cut-offfing of isolating switch, and concrete calculating also can be calculated according to relative electric life formula; Because our slave computer sample record is the dropout current value of isolating switch mutual inductor secondary side, in order to obtain the actual dropout current value of isolating switch, must electric current be turned over back according to the no-load voltage ratio value of mutual inductor, therefore also need to know the no-load voltage ratio value of isolating switch mutual inductor; Because we monitor the electric life of each phase of every isolating switch, so will know the operation numbering and the corresponding sequence number separate and on our covering device of isolating switch; In transformer station, reason owing to the mode of connection of system, in addition again because we can not introduce relay protection signal from system, but whether be zero to judge whether isolating switch cut-offs according to the electric current by isolating switch, just there is the problem of a subordinate relation in this, so will introduce a subordinate code; In addition, for the convenience of problem analysis, the parameter that we simultaneously also also are defined as isolating switch with the accumulative total dropout current value and the accumulative total open and close times of isolating switch,
Host computer is the main frame of primary cut-out electric service life monitor system, mainly finish the record of dropout current, the calculating of electrical wear and electric life, the inserting and revising of circuit breaker parameters, cut-off the inquiry of record, report to the police, isolating switch cut-offs the functions such as printing of parameter, machine account table, use for convenience, this software adopts the Chinesizing drop-down menu under the graphics mode to design.Fig. 5 has provided the slave computer main program flow chart, and Fig. 6 has provided the interrupt service routine process flow diagram, and Fig. 7 has provided the upper computer software functional structure chart.
Claims (4)
1; a kind of contact of breaker electrical endurance monitoring apparatus; comprise host computer and slave computer; host computer is an industrial computer; slave computer is made up of the polylith sampling plate; it is characterized in that connecting by dual port RAM between host computer and the slave computer; the address and the data bus that are host computer are received on the dual port RAM; the address of slave computer and data bus are also received on the dual port RAM; every block signal sampling plate comprises signal acquisition circuit (1); holding circuit (2); multi-way switch; penetrate a grade follower; precise rectification circuit; A/D converter and CPU; the sample resistance R2 of signal acquisition circuit passes through by C1; the holding circuit that D1-D4 forms connects multi-way switch; the multi-way switch back connects penetrates a grade follower; the output of penetrating grade follower connects precise rectification circuit; the output termination AD converter of precise rectification circuit; the output of AD converter meets CPU, and address and the data bus of CPU are received on the dual port RAM.
2, contact of breaker electrical endurance monitoring apparatus according to claim 1; it is characterized in that signal sample circuit adopts punching secondary current mutual inductor; this mutual inductor is placed on the secondary line that connects protective relay of a CT of isolating switch, and sample resistance R2 links by shielded cable and mutual inductor secondary coil.
3, contact of breaker electrical endurance monitoring apparatus according to claim 2, it is characterized in that having resistance R 1 to be connected in parallel on the secondary sample resistance of secondary CT in the punching secondary transformer circuit that signal sample circuit adopts, when R2 got 40 Ω, the no-load voltage ratio of mutual inductor got 1000/1.
4, contact of breaker electrical endurance monitoring apparatus according to claim 1 and 2 is characterized in that multi-way switch adopts digit chip CD4067.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 01239795 CN2476033Y (en) | 2001-04-13 | 2001-04-13 | Device for monitoring circuit breaker contact head electric service life |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 01239795 CN2476033Y (en) | 2001-04-13 | 2001-04-13 | Device for monitoring circuit breaker contact head electric service life |
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| Publication Number | Publication Date |
|---|---|
| CN2476033Y true CN2476033Y (en) | 2002-02-06 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 01239795 Expired - Fee Related CN2476033Y (en) | 2001-04-13 | 2001-04-13 | Device for monitoring circuit breaker contact head electric service life |
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| Country | Link |
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| CN (1) | CN2476033Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101819255A (en) * | 2010-04-16 | 2010-09-01 | 上海申瑞电力科技股份有限公司 | Nonlinear method for computing effective open and close times of breaker |
| CN103616634A (en) * | 2013-11-30 | 2014-03-05 | 国家电网公司 | Method and device for transformer on-load tap switch contact service life online monitoring |
-
2001
- 2001-04-13 CN CN 01239795 patent/CN2476033Y/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101819255A (en) * | 2010-04-16 | 2010-09-01 | 上海申瑞电力科技股份有限公司 | Nonlinear method for computing effective open and close times of breaker |
| CN101819255B (en) * | 2010-04-16 | 2014-11-19 | 上海申瑞继保电气有限公司 | Nonlinear method for computing effective open and close times of breaker |
| CN103616634A (en) * | 2013-11-30 | 2014-03-05 | 国家电网公司 | Method and device for transformer on-load tap switch contact service life online monitoring |
| WO2015078030A1 (en) * | 2013-11-30 | 2015-06-04 | 国家电网公司 | Method for monitoring lifetime of transformer on-load tap-changer contact online and apparatus therefor |
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| CF01 | Termination of patent right due to non-payment of annual fee |