SE445274B

SE445274B - Device for monitoring the condition of electrical contacts with circuit-breaking contacts, especially winding switches

Info

Publication number: SE445274B
Application number: SE8107467A
Authority: SE
Inventors: H Goransson
Original assignee: Asea Ab
Priority date: 1981-12-14
Filing date: 1981-12-14
Publication date: 1986-06-09
Also published as: SE8107467L

Abstract

The invention is a device for monitoring the condition of electrical devices with circuit-breaking contacts, such as high voltage breakers, circuit couplers, etc. The device consists of gauges (2, 7) for measuring arc energy, a calculation device (1) for calculating the contact burn-off that corresponds to the measured arc energy, and a presentation device (11c) for registering the degree of the total contact burn-off since the last check.<IMAGE>

Description

15 25 8107467-6 2 patentki-av 1 angivna särdragen. Eftersom graden av kontaktavbränning utgör en funktion av ljusbágsenergin mäts eller beräknas denna. storhet och siffer- värden för ekvivalent kontaktavbränning presenteras. 8 patent 8107467-6 2 patent specification of 1 stated. Since the degree of contact burning constitutes a function of the arc energy, it is measured or calculated. size and numerical values for equivalent contact burnout are presented.

Fördelen med en anordning av detta slag är bl a att en sälmare bestänming av serviceintervallen kan erhållas och kostsamma urdrifttaganden och inspek- tioner kan undvikas. Vidare kan man erhålla uppgifter om onormalt långa ljusbågstider, vilka kan användas som laxmsigxaler om felfunktion hos appa- raten.The advantage of a device of this kind is, among other things, that a more accurate determination of the service intervals can be obtained and costly decommissioning and inspections can be avoided. Furthermore, information can be obtained about abnormally long arc times, which can be used as salmon signals on malfunction of the device.

Uppfinningen skall närmare förklaras genom 'beslnzivning av ett utförings- exempel under hänvisning till bifogade ritning, i vilken fig 1 visar ett principschema för en övervalcníngsanordning enligt uppfinningen och fig 2 visar ett exempel på ett programförloppsdiagram för en sådan anordning.The invention will be further elucidated by describing an exemplary embodiment with reference to the accompanying drawing, in which Fig. 1 shows a schematic diagram of an overflow device according to the invention and Fig. 2 shows an example of a program flow diagram for such a device.

Den i ritningen visade anordningen är avsedd att övervaka strömbrytande kontakter i t e: en enfasig eller trefasig lindningskopplare. Huvudkompo- nenten i anordningen är ett beräkningeorgan 1 i fom av en mih-oprocessor eller annan logisk bets. Beräkningsorganet 1 mottar information om ljus- bågsenergins storlek från ett eller flera mätorgan. Ljusbâgsenergin kan niaïtas direkt eller indirekt, exempelvis genom mätning eller avkänning av ljusbâgens ström, spänning, ljud, ljus, temperatur eller elektromagnetiska strålning eller en kombination av dessa storheter. I det visade utförings- exemplet mäts dels strönmen i ljusbâgen, dels ljusbågstiden genom avkänning av den elektromagnetiska. strålningen från ljusbågen. Ur dessa tvâ. uâtsigxxsler, vilka tillföres berälmingsorganet 1, kan ett approximativt värde på ljusbågs- energin beräknas, eftersom ljusbågsspänningen i den aktuella applikationen kan förutsättas vara i det nämaste konstant.The device shown in the drawing is intended to monitor switching contacts in a single-phase or three-phase winding coupler. The main component of the device is a computing means 1 in the form of a mih-processor or other logic bit. The calculation means 1 receives information about the magnitude of the arc energy from one or more measuring means. The arc energy can be used directly or indirectly, for example by measuring or sensing the arc's current, voltage, sound, light, temperature or electromagnetic radiation or a combination of these quantities. In the embodiment shown, the current in the arc is measured partly by the arc time by sensing the electromagnetic. the radiation from the arc. Out of these two. In addition, which are supplied to the arcuating means 1, an approximate value of the arc energy can be calculated, since the arc voltage in the current application can be assumed to be almost constant.

Strömnñtningen utföres med en krets som omfattar en strömtransfomator .2 med 'belastningsmotstånd 3, en likriktarbrygga. 4, en filterkondensator 5 och en analog-digitalomvandlare 6.The mains supply is carried out with a circuit comprising a current transformer .2 with a load resistor 3, a rectifier bridge. 4, a filter capacitor 5 and an analog-to-digital converter 6.

Ifaïtningen av ljusbâgstiden utföres med en krets som omfattar en HI-mottagare 7, en förstärkare 8 och en nivâdetektor 9.The arcing of the arc time is performed with a circuit comprising an HI receiver 7, an amplifier 8 and a level detector 9.

Berälmingsorganet 1 är för-programmerat att lag-a och bearbeta informtionen från nätorganen och att som resultat avge bl e. en sigzal som representerar 'Den kontaktavbränning, felsignaler om långa ljusbâgstider etc. Dessa sigxaler förstärkas med hjälp av transistorer 10 och tillföras ett antal 10 15 25 3» 8107467-6 elmekaniska räkneverk. I ritningen visas tre sådana räkneverk 11a-11c, av vilka :rrêikneverket 11a visar totala antalet kopplingar som apparaten utfört sedan närmast föregående kontrolltillfälle, rälmeverket 11b visar antalet kopplingar vid strömmar överstigande ett visst gränsvärde och räkneverket 11c visar antalet ekvivalenta kopplingar vid ﬁzllastström.The signaling means 1 is pre-programmed to store and process the information from the network means and to result in, among other things, a signal signal representing the contact burn-off, error signals of long arc times, etc. These signal signals are amplified by means of transistors 10 and applied to a number 10. 15 25 3 »8107467-6 electromechanical counters. The drawing shows three such counters 11a-11c, of which: the counter 11a shows the total number of connections made by the apparatus since the most recent inspection, the rail 11b shows the number of connections at currents exceeding a certain limit value and the counter 11c shows the number of equivalent connections at load current.

Utifrån den vid varje koppling uppmätta. ljusbågsenergin beräknas: beräknings- organet 1 den motsvarande kontaktavbränningen. Denna avbränning följer approximativt en potensfunktion av strömmen, där strömmens exponent kan fastställas experimentellt. Vanligtvis ligger denna exponent mellan 1 ,5 och 2,0. Det framrälczzade värdet på. kontaktavbränningen lagras tillfälligt i ett register i beräkningsenheten och motsvarande värden för de efterfölj- ande kopplingarna adderas till registervärdet. 'Varje gång registervärdet uppnår det värde för kontaktavbränningen som uppstår 'under en brytning vid fullastström ges en impuls till räkneverket 11o som därvid räknar fram ett steg. Då det av räkneverket 11c visade antalet fullastkopplingswr uppgår till ett på en aiffertablå. 12 på. räkneverket 11o förinställt värde, erhålles sig- nal via en alarmledning 13.Based on the one measured at each connection. the arc energy is calculated: the calculation means 1 the corresponding contact burn-off. This burning follows approximately a power function of the current, where the exponent of the current can be determined experimentally. Usually this exponent is between 1, 5 and 2.0. The forward value of. the contact burn-off is temporarily stored in a register in the calculation unit and the corresponding values for the subsequent connections are added to the register value. 'Each time the register value reaches the value for the contact burn-off that occurs' during a break at full load current, an impulse is given to the counter 110 which then calculates a step. When the number of full-coupling wr shown by the counter 11c amounts to one on an aiffer plate. 12 on. counter 11o preset value, signal is received via an alarm line 13.

Genom z-älcneverken 11a och 11b kan man fastställa om apparaten bör genomgå. underhâllsservioe innan signal erhållits via alemledningen 13. Vissa delar i apparaten utsätts nämligen för ett visst mekanisktsslitage vid varje kopp- ling oberoende av om kopplingen sker med eller utan ström. Bä-kneverket 11a ger information om när service p g a sådant mekaniskt slitage är nödvändig.Through the z-power plants 11a and 11b it can be determined whether the apparatus should undergo. maintenance servo before a signal is received via the supply line 13. Certain parts of the device are exposed to a certain amount of mechanical wear at each connection, regardless of whether the connection is made with or without current. The crankcase 11a provides information on when service due to such mechanical wear is necessary.

Om kopplingar utförts vid strömmar som avsevärt överstiger apparatens märk- ström, kan det vara lämpligt att så snart som möjligt efteråt öppna appara- ten för inspektion. Information om eventuella sådana kopplingar erhålles genom räkneverket 11b.If connections have been made at currents that significantly exceed the rated current of the device, it may be appropriate to open the device for inspection as soon as possible afterwards. Information on any such connections is obtained through the counter 11b.

I stället för de visade elmekaniska räkneverken kan man använda en elektro- nisk sifferirxdikator (display) av i marknaden förekomande slag med icke- flyktig: minne.Instead of the electromechanical counters shown, an electronic number indicator (display) of the type available on the market with non-volatile memory can be used.

För att nedbringa kostnaden för övervakningsutrustningen kan man lämpligen använda en ooh sanna sifferindikator för presentation av flera olika mät- resultat. Sifferindikatorn ansluts därvid via plug-in-kontakter eller om- kopplare i tur och ordning till olika fasta minnesenheter sm är kopplade till beräkningsorganet.To reduce the cost of the monitoring equipment, it is convenient to use an ooh true number indicator for the presentation of several different measurement results. The numerical indicator is then connected via plug-in connectors or switches in turn to various fixed memory units which are connected to the calculation means.

Claims

1. 8107467-6 4 The arc indication for determining the arc time can be achieved in several sim ways. In Shane: for the shown receiver 7 for lockbox electromagnetic radiation, light-sensing means with 011125-8118 fibers or means affected by the sound or temperature of the arc can be used. PATEHTKRÅV 1. Device for monitoring the condition of electrical appliances with switching contacts, in particular winding couplers, characterized in that the device comprises measuring means (2, 7) for measuring the arc energy during each connection, a calculating means (1) which is connected to said measuring means and arranged to calculate a contact burn corresponding to the measured arc energy and a presentation means (11c) which is controlled from the calculating means (1) and arranged to register the degree of the total contact burning after the next preceding control means, said means comprising (2) for measuring the current through the contacts and means (7) for detecting the presence of an arc between the contacts.

Device according to claim 1, characterized in that said. arc detecting means (7) is constituted by a receiver, the output of which depends on the electromagnetic radiation of the arc. 5.

The device according to the patent claims is characterized in that said arc detecting means is constituted by a light detector.

4. A device according to claim 1, characterized in that said arc detecting means is constituted by a means which is arranged to be influenced by the sound from the arc.

5. Device according to any one of the preceding claims, characterized in that the presentation gas (110) is connectable to the other equipment via. plug-in connectors or switches, one and true. presentation means can be used for presentation of different. the immediate result. 8107467-6 6.

A device according to any one of the preceding pacentmv, characterized in that in connection with said presentation means (110) means are arranged for emitting an alarm signal when the contact burning has reached a predetermined level. 'l.

Device according to any one of the preceding claims, characterized in that the device comprises: a second presentation means (Ha) which is arranged to register the total number of connections made since the immediately preceding control case.

8. A device according to any preceding patent claim, characterized in that the device comprises a third presentation gene (m) which is arranged to record the number of connections which have been made at currents exceeding one predetermined value, which is higher than the rated current of the device.

Device according to any one of the preceding claims, characterized in that the device contains means for detecting and / or alarming in the case of couplings with abnormally long. ljuabågstider.