DK146609B - FAULT CURRENT RELAY - Google Patents
FAULT CURRENT RELAY Download PDFInfo
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- DK146609B DK146609B DK186268A DK186268A DK146609B DK 146609 B DK146609 B DK 146609B DK 186268 A DK186268 A DK 186268A DK 186268 A DK186268 A DK 186268A DK 146609 B DK146609 B DK 146609B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
- H02H3/32—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors
- H02H3/33—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors using summation current transformers
- H02H3/332—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors using summation current transformers with means responsive to dc component in the fault current
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- Power Engineering (AREA)
- Emergency Protection Circuit Devices (AREA)
- Breakers (AREA)
- Relay Circuits (AREA)
Description
146609 i 1 Opfindelsen angår et fejlstrømsrelæ til overvågning af sumstrømmen i to eller flere ledere af et net med en sumstrømtransformator med en jernkerne, hvis primærviklinger er forbundet med nettets ledere, og til hvis 5 som udløsevikling tjenende sekundærvikling er sluttet et udløseorgan, der bevirker udløsning, når der sker jordovergang.The invention relates to a residual current current relay for monitoring the sum current in two or more conductors of a network with a sum current transformer with an iron core, the primary windings of which are connected to the conductors of the network, and to which a trigger means for tripping is connected. , when there is a ground crossing.
Er der ingen afledningsfejl i de til nettet gennem 10 sumstrømtransformatoren forbundne forbrugere, vil de indgående og udgående strømme ophæve hinanden i sumstrømtransformatoren, og ingen spænding vil dannes i sekundærviklingen. Er der derimod vekselstrømsafledningsfejl blot i en af forbrugerne, vil der i sum-15 strømtransformatorens primære vikling mangle en tilsvarende strøm i differencen mellem de indgående og udgående strømme, og en tilsvarende spænding vil dannes i sumstrømtransformatorens sekundærvikling, og denne vil bevirke udløsning, når den når en forudbestemt 20 størrelse. Optræder der derimod, jævnstrømsafledningsfejl fx i et i forbrugerne indgående ensretteranlæg, vil en tilsvarende jævnstrøm ganske vist mangle i sumstrømmen gennem sumstrømtransformatoren, men denne jævnstrøm vil ikke inducere nogen spænding i sekundær-25 vikling, men tværtimod i de fleste tilfælde bevirke en magnetisering af sumstrømtransformatorens jernkerne, der i de fleste tilfælde vil nedsætte følsomheden over for samtidigt optrædende vekselstrømme. Tidligere kendte fejlstrømsrelæer af den angivne art vil derfor 50 ikke give nogen beskyttelse mod indtræffende jævnstrømsfejlstrømme.If there are no dissipation errors in the consumers connected to the mains through the sum current transformer, the incoming and outgoing currents will cancel each other out in the sum current transformer, and no voltage will be formed in the secondary winding. If, on the other hand, there is an AC fault in just one of the consumers, the primary winding of the sum current transformer will lack a corresponding current in the difference between the incoming and outgoing currents, and a corresponding voltage will be formed in the secondary current of the sum current transformer. reaches a predetermined 20 size. If, on the other hand, a direct current fault occurs, for example in a rectifier system included in the consumer, a corresponding direct current will admittedly be missing in the sum current through the sum current transformer, but this direct current will not induce any voltage in secondary winding, but on the contrary in most cases the iron cores, which in most cases will reduce the sensitivity to simultaneously occurring alternating currents. Therefore, prior art residual current relays of the type indicated will not provide any protection against occurring direct current fault currents.
Pra tysk patentskrift 1 146 181 kendes et fejlstrømsrelæ af den angivne art, hvor den i sekundærviklingen frem-55 bragte strøm forstærkes i en med denne forbundet tran- 2 146609 1 sistorforstærker. Transistorforstærkeren fødes med jævnstrøm gennem en ensretter forbundet med nettet. Jævnstrømmen er ført gennem en særlig vikling på sumstrømtransformatoren og bevirker herved en jævn-5 strømsformagnetisering af dennes kerne. Herved kan man opnå at få sumstrømtransformatoren til at arbejde på et gunstigt punkt af dens magnetiseringskarakteristik og herved forøge dens følsomhed over for vekselfejlstrømme. Nogen beskyttelse over for jævnstrøms-10 fejlstrømme kan man imidlertid ikke opnå på denne måde, thi en optrædende jævnstrømsfejlstrøm vil blot bevirke en mætning af transformatorens jernkerne og en forskydning bort fra det gunstige arbejdspunkt, og herved nedsætte transformatorens følsomhed over 15 for vekselfejlstrømme uden at frembringe nogen spænding i sekundærviklingen. Heller ikke med dette relæ kan der derfor opnås nogen beskyttelse over for jævnstrømsfej lstrømme.German Pat. No. 1,146,181 discloses a residual current current relay of the type indicated, in which the current generated in the secondary winding is amplified in a transistor amplifier connected thereto. The transistor amplifier is fed with direct current through a rectifier connected to the mains. The direct current is passed through a special winding on the sum current transformer and thereby causes a direct current magnetization of its core. Hereby it is possible to make the sum current transformer operate at a favorable point of its excitation characteristic and thereby increase its sensitivity to alternating current currents. However, no protection against direct current-10 residual currents can be obtained in this way, for an occurring direct-current residual current will only cause a saturation of the iron core of the transformer and a displacement away from the favorable operating point, thereby reducing the sensitivity of the transformer to alternating residual currents. any voltage in the secondary winding. Therefore, even with this relay, no protection against direct current fault currents can be obtained.
20 Det er opfindelsens formål at anvise et fejlstrømsrelæ af den angivne art, der reagerer både over for vekselstrømsfejlstrømme som over for jævnstrømsfejlstrømme eller en kombination af begge, og det opnås ifølge opfindelsen ved, at sumstrømtransforma-25 torens jernkerne til konstatering af en gennem lederne flydende fejlstrøm er sluttet til en hjælpevikling, der fører en ren vekselstrøm, der formagnetiserer kernen og i sekundærviklingen frembringer en vekselstrømsreferencespænding, i forbindelse med et, i og 30 for sig kendt udløseorgan, der udløser såvel ved stigende som ved faldende spænding. I relæet ifølge opfindelsen vil udløseorganet således konstant overvåge den i sekundærviklingen frembragte referencespænding og bevirke udløsning, hvis denne ændrer sig, 35 hvad enten det skyldes, at den forøges på grund af 146609 3 1 forekommende vekselfejlstrømme,. eller formindskes på grund af jævnstrømsfejlstrømme. Det vil forstås, at også i det tilfælde, at der samtidig forekommer en vekselfejlstrøm, der forøger referencespændingen, 5 og en jævnstrømsfejlstrøm, der formindsker den lige så meget, vil relæet kunne bringes til at udløse. En sådan samtidig forekomst af jævnstrømsfejlstrømme og vekselfejlstrømme vil nemlig ikke kunne undgå at bevirke en forvrængning af referencesignalet, og 10 ved at lade udløseorganet sammenligne referencesignalet med et rent sinusformet signal vil ikke blot en ændring af referencesignalets størrelse kunne konstateres, men også en forvrængning af denne.It is the object of the invention to provide a residual current current relay of the type indicated which responds both to alternating current residual currents and to direct current residual currents or a combination of both, and it is achieved according to the invention in that the sum core transformer's iron core for detecting a flow through the conductors residual current is connected to an auxiliary winding which carries a pure alternating current which pre-magnetises the core and in the secondary winding produces an alternating current reference voltage, in connection with a tripping means known per se, which triggers both rising and falling voltage. Thus, in the relay according to the invention, the tripping means will constantly monitor the reference voltage generated in the secondary winding and cause tripping if it changes, whether it is due to it being increased due to alternating current currents occurring. or decreases due to DC fault currents. It will be understood that even in the event that an alternating fault current occurs which increases the reference voltage and a direct current fault current which decreases it just as much, the relay can be caused to trip. Such a simultaneous occurrence of direct current fault currents and alternating fault currents will not be able to avoid causing a distortion of the reference signal, and by having the trigger means compare the reference signal with a purely sinusoidal signal, not only a change in the magnitude of the reference signal can be observed. .
15 Ifølge opfindelsen kan primærviklingen på en hjælpetransformator med en kerne som en bestanddel af udløseorganet være sluttet til en vekselstrømskilde, idet primærviklingen er serieforbundet med sumstrømtrans-formatorens hjælpevikling, medens hjælpetransformato-20 rens sekundærvikling til spændingssammenligning med sumstrømtransformatorens sekundærvikling er koblet på en sådan måde til udløseorganets elektromekaniske del, at spændingerne over udløseviklingen og hjælpetransformatorens sekundærvikling ved ikke overlejrende 25 jævnstrømsformagnetisering i sumstrømtransformatoren er lige store og modsat rettede. Er de to transformatorer ens dimensioneret, vil de afgive ens signaler, så længe der ingen fejlstrømme forekommer, men ved forekomst af en veksel- eller jævnfejlstrøm, eller ved 30 samtidig forekomst af begge, der henholdsvis forøger, formindsker eller forvrænger referencesignalet, medens signalet fra hjælpetransformatoren forbliver upåvirket, vil udløseorganet kunne konstatere forskellen og bringe relæet til udløsning.According to the invention, the primary winding of an auxiliary transformer with a core as a component of the tripping means may be connected to an AC power source, the primary winding being connected in series with the auxiliary winding of the auxiliary current transformer, while the auxiliary transformer secondary winding for voltage comparison with the auxiliary transformer the electromechanical part of the trip means that the voltages across the trip winding and the secondary winding of the auxiliary transformer by non-overlying direct current magnetization in the sum current transformer are equal and opposite. If the two transformers are of the same dimension, they will emit the same signals as long as there are no residual currents, but in the event of an alternating or direct current, or in the case of a simultaneous occurrence of both, which increase, decrease or distort the reference signal, while the signal from the auxiliary transformer remains unaffected, the tripping means will be able to detect the difference and bring the relay to tripping.
35 16660935 166609
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1 Ifølge opfindelsen kan sumstrømtransformatoren og hjælpetransformatoren have en fælles jernkerne med to magnetiske kredse, hvoraf den ene udgør sumstrøm-transformatorens kerne, og den anden udgør hjælpe-5 transformatorens kerne, hvorhos hjælpeviklingen ligger på en fælles gren for de to magnetiske kredse, medens udløseviklingen og sekundærviklingen på hjælpetransformatoren er koblet i serie og modsat rettede. Da en fejlstrøm kun vil påvirke den ene kreds, men ikke 10 hjælpetransformatorkredsen, vil man herved med en enkelt transformator kunne opnå samme funktion som ovenfor med to separate transformatorer.According to the invention, the sum current transformer and the auxiliary transformer may have a common iron core with two magnetic circuits, one of which constitutes the core of the sum current transformer and the other constitutes the core of the auxiliary transformer, the auxiliary winding lying on a common branch of the two magnetic circuits. and the secondary winding of the auxiliary transformer is connected in series and in the opposite direction. Since a fault current will only affect one circuit, but not the auxiliary transformer circuit, it will be possible to achieve the same function with a single transformer as above with two separate transformers.
Ifølge opfindelsen kan hjælpeviklingen være modkoblet 15 udløseviklingen og dimenstioneret på en sådan måde, at den i udløsestrømkredsen inducerede spænding er kompenseret ved fejlfri tilstand. Udløseviklingen og hjælpeviklingen kan fx danne en transformator med omsætningsforhold 1:1, der overfører netspændingen 20 til udløsekredsen, hvori netspændingen også er indkoblet direkte, men modsat rettet den gennem den således dannede transformator overførte spænding. Forekommer der ingen fejlstrøm, vil de to spændinger ophæve hinanden, og udløseorganet forblive uvirksomt.According to the invention, the auxiliary winding can be counter-coupled to the tripping winding and dimensioned in such a way that the voltage induced in the tripping current circuit is compensated by fault-free state. The tripping winding and the auxiliary winding can, for example, form a transformer with a conversion ratio of 1: 1, which transmits the mains voltage 20 to the tripping circuit, in which the mains voltage is also switched on directly, but in the opposite direction the voltage transmitted through the transformer thus formed. If there is no residual current, the two voltages will cancel each other out and the trigger means will remain inactive.
25 Forekommer der derimod en vekselfejlstrøm, en jævnfejlstrøm eller en kombination af begge, vil den overførte spænding henholdsvis forøges eller formindskes eller blot forvrænges, medens den direkte i kredsen indkoblede netspænding vil forblive uforandret.If, on the other hand, there is an alternating fault current, a direct current or a combination of both, the transmitted voltage will increase or decrease or simply distort, respectively, while the mains voltage directly connected in the circuit will remain unchanged.
30 i alle tre tilfælde vil der forekomme en afvigelse mellem de to spændinger, der vil kunne bevirke udløsning af relæet. På denne måde vil relæet ifølge opfindelsen kunne fungere med en enkelt transformator med kun én magnetisk kreds.30 in all three cases there will be a deviation between the two voltages which could cause the relay to trip. In this way, the relay according to the invention will be able to operate with a single transformer with only one magnetic circuit.
35 146609 5 1 Ifølge opfindelsen kan den på sumstrømtransformato-rens kerne monterede udløsevikling være indkoblet i en brokobling* i hvis ene diagonal udløseorganet er anbragt, og hvor vekselstrømskilden er indkoblet 5 i den anden diagonal, hvorhos hjælpeviklingen og udløseviklingen falder sammen til en enhed. Pra broens spændingskilde sendes en strøm gennem autotransformatoren, og det herved frembragte spændingsfald sammenlignes med et spændingsfald frembragt af en strøm fra 10 samme spændingskilde, fx over en med autotransformatoren identisk opbygget selvinduktion. Forefindes der ingen fejlstrøm i sumstrømtransformåtoren, vil de to spændingsfald være ens, og relæet være i ro. Optræder der derimod en veksel- eller jævnstrømsfejlstrøm 15 eller en blanding af begge, vil spændingen over autotransformatoren, der har fælles kerne med sumstrøm-transformatoren, henholdsvis forøges, svækkes eller forvrænges. Det vil i alle tilfælde afvige fra spændingsfaldet over sammenligningsimpedansen i broen, og 20 relæet vil bringes til udløsning. Til opbygning af et sådant relæ kræves ud over de i broen indgående elektroniske komponenter kun en sædvanlig sumstrømtrans-formator uden særlige viklinger, og det vil derfor kunne fremstilles uden væsentlige ekstraomkostninger, 25 ligesom det vil kunne benyttes i forbindelse med eksisterende sumstrømtransformatorer.According to the invention, the tripping winding mounted on the core of the sum current transformer may be connected in a bridge coupling * in one of which diagonal tripping means is arranged, and in which the alternating current source is connected in the other diagonal, the auxiliary winding and the tripping winding coinciding into a unit. The voltage source of the Pra bridge is sent a current through the autotransformer, and the voltage drop generated thereby is compared with a voltage drop generated by a current from the same voltage source, for example over a self-induction built up identically with the autotransformer. If there is no residual current in the sum current transformer, the two voltage drops will be the same and the relay will be at rest. If, on the other hand, an alternating or direct current fault current 15 or a mixture of both occurs, the voltage across the autotransformer having a common core with the sum current transformer will increase, weaken or distort, respectively. It will in all cases deviate from the voltage drop across the comparison impedance in the bridge and the relay will be triggered. In order to build such a relay, in addition to the electronic components included in the bridge, only a conventional sum current transformer without special windings is required, and it will therefore be possible to manufacture it without significant additional costs, just as it can be used in connection with existing sum current transformers.
Ifølge opfindelsen kan vekselstrømmen til den på sum-strømtransformatoren anbragte hjælpevikling tages 30 fra det af fejlstrømsrelæet beskyttede net. Hjælpeviklingen kan fx være koblet til det beskyttede net over en modstand eller være sluttet til dette over en transformator. Herved spares en særlig spændingskilde til frembringelse af referencespændingen.According to the invention, the alternating current of the auxiliary winding arranged on the sum current transformer can be taken from the network protected by the residual current current relay. The auxiliary winding can, for example, be connected to the protected mains via a resistor or be connected to this via a transformer. This saves a special voltage source for generating the reference voltage.
35 6 146609 1 Ifølge opfindelsen kan hjælpeviklingen fødes fra en særskilt generator. Generatoren kan ifølge opfindelsen have en frekvens, der er væsentlig højere end frekvensen af det beskyttede net. Herved kan relæets .35 6 146609 1 According to the invention, the auxiliary winding can be fed from a separate generator. According to the invention, the generator can have a frequency which is significantly higher than the frequency of the protected network. Hereby the relay can.
5 følsomhed forøges.5 sensitivity increases.
I det følgende skal opfindelsen forklares nærmere under henvisning til tegningen, hvor 10 fig. 1 viser et konventionelt fejlstrømsrelæ, anvendt i forbindelse med et vekselstrømsnet og et vekselstrømsforbrugsapparat, fig. 2 samme fejlstrømsrelæ anvendt i forbindelse med et vekselstrømsnet, en ensretter og 15 et jævnstrømsforbrugsapparat, fig. 3 skematisk et anlæg, hvor der er anbragt et fejlstrømsrelæ som vist i fig. 1 og 2, og hvor der fra dette forsynes tre strømforbrugsapparater, hvoraf det ene 20 har en ensretter, fig. 4 et diagram over udløsestrømmens variation med en gennem fejlstrømsrelæet gående jævnstrøm, fig. 5 et fejlstrømsrelæ ifølge opfindelsen, anvendt 25 i forbindelse med et enfaset vekselstrømsnet, fig. 6 et fejlstrømsrelæ ifølge opfindelsen af en anden udførelsesform, fig. 7 et fejlstrømsrelæ ifølge opfindelsen af en tredie udførelsesform, og 30 fig, 8 et fejlstrømsrelæ ifølge opfindelsen af en fjerde udførelsesform.In the following, the invention will be explained in more detail with reference to the drawing, in which fig. Fig. 1 shows a conventional residual current relay used in connection with an alternating current network and an alternating current consumption apparatus; 2 shows the same residual current device used in connection with an alternating current network, a rectifier and a direct current consumption device, fig. 3 schematically shows a system in which a residual current current relay is arranged as shown in fig. 1 and 2, and from which three power consumption devices are supplied, one of which has a rectifier, fig. 4 is a diagram of the variation of the tripping current with a direct current passing through the residual current relay, FIG. Fig. 5 shows a residual current current relay according to the invention used in connection with a single-phase alternating current network; Fig. 6 shows a residual current current relay according to the invention of another embodiment; Fig. 7 shows a residual current current relay according to the invention of a third embodiment, and Fig. 8 shows a residual current current relay according to the invention of a fourth embodiment.
Det i fig. 1 viste fejlstrømsrelæ har en ringformet magnetkerne i, hvorigennem der er ført tre faseledere 35 og en nulleder til et trefase-vekselstrømsforbrugs- 146609 7 1 apparat 2, som har en jordforbindelsesledning 3.The device shown in FIG. 1 has an annular magnetic core in which three phase conductors 35 and a neutral conductor are passed to a three-phase alternating current consumption apparatus 2 which has a ground connection line 3.
Om kernen 1 er der anbragt en sekundærvikling 4, der er forbundet med et udløseorgan 5, som betjener afbrydere 6, der er indskudt i de tre faseledere og 5 nullederen foran kernen 1. Forsyningsnettet er jordforbundet gennem en jordledning 7· En vekselstrømsafledning gennem ledningen 3 vil bevirke en ubalance i sumstrømmen gennem kernen 1, så at viklingen 4 bringer udløseorganet 5 til at udløse. I tilfælde 10 af en jævnstrømsafledning gennem ledningen 3, vil den deraf resulterende jævnstrøm gennem kernen 1 ikke bevirke induktion af en strøm i viklingen 4 og derfor ikke et signal til udløsning af udløseorganet 5, men jævnstrømmen gennem kernen vil bevirke en 15 ændring af arbejdspunktet for sumstrømtransformatoren 1,4, jævnfør fig. 4, så at der kræves en kraftigere vekselstrømsafledning gennem ledningen 3 for at bringe udløseorganet 5 til at udløse.Around the core 1 a secondary winding 4 is arranged, which is connected to a release means 5, which actuates switches 6, which are inserted in the three phase conductors and 5 the neutral conductor in front of the core 1. The supply network is earthed through a ground line 7 · An alternating current drain through the line 3 will cause an imbalance in the sum flow through the core 1, so that the winding 4 causes the release means 5 to release. In case 10 of a direct current discharge through the line 3, the resulting direct current through the core 1 will not cause induction of a current in the winding 4 and therefore not a signal for tripping of the trigger means 5, but the direct current through the core will cause a change of the operating point of the sum current transformer 1.4, cf. fig. 4, so that a more powerful alternating current drain is required through the line 3 to cause the trigger means 5 to trip.
20 Når sumstrømtransformatoren som vist i fig. 2 er sluttet til en ensretter 8, der driver et jævnstrømsforbrugsapparat 9, er faren for en sådan jævnstrømsafledning til jord særlig stor, medens faren for en vekselstrømsafledning er ringe. Det viste fejs-25 strømsrelæ er ikke egnet til et sådant kredsløb, idet det ikke vil afbryde for jævnstrømsafledning til jord.When the sum current transformer as shown in FIG. 2 is connected to a rectifier 8, which operates a direct current consumption apparatus 9, the danger of such a direct current discharge to earth is particularly great, while the danger of an alternating current discharge is small. The fault current relay shown is not suitable for such a circuit, as it will not cut off direct current to ground.
I fig. 3 er der anbragt et fejlstrømsrelæ 10 som det 30 i fig. 1 og 2 viste fejlstrømsrelæ 1, 4, 5» 6. Relæet 10 forsyner gennem manuelt betjente afbrydere 11 tre strømforbrugende apparater, hvoraf de to 12 og 13 er vekselstrømsforbrugende, medens det tredie 14 er jævnstrømsforbrugende og fødes gennem en ensretter 35 15. De tre apparater 12, 13 og 14 er jordforbundet 8 146609 1 hver for sig. Hvis der sker jævnstrømsafledning fra apparatet 14, vil fejlstrømsrelæet 10 ikke reagere.In FIG. 3, a residual current current relay 10 such as that 30 in FIG. 1 and 2, the relay 10 supplies three power-consuming devices through manually operated switches 11, the two 12 and 13 of which are alternating current-consuming, while the third 14 is DC-consuming and is fed through a rectifier 35 15. The three appliances 12, 13 and 14 are grounded 8 146609 1 separately. If direct current is dissipated from the apparatus 14, the residual current relay 10 will not respond.
Der vil gennem kernen i relæet 10 gå en jævnstrøm, der bevirker en formagnetisering af kernen, så at 5 dennes arbejdspunkt forskydes. I fig. 4 er vist virkningen heraf, idet der i abscisseretningen er afsat den gennem transformatorkernen gående jævnstrøm, medens der i ordinatretningen er afsat den fornødne fejlvekselstrøm til udløsning af udløseorganet 5.A direct current will flow through the core of the relay 10, which causes a pre-magnetization of the core, so that its operating point is displaced. In FIG. 4 shows the effect thereof, in that the direct current passing through the transformer core is deposited in the abscissa direction, while in the ordinate direction the necessary alternating current is deposited for tripping the trigger means 5.
10 Den fornødne fejlvekselstrøm til udløsning, når jævnstrømsfejlstrømmen er nul, er angivet ved In.10 The required residual current current for tripping when the direct current residual current is zero is indicated by In.
Det vil ses, at den fornødne fejlvekselstrøm til . udløsning af udløseorganet stiger stærkt ved fejljævnstrømmen Ide. Når der sker en fejljævnstrøms-15 afledning fra apparatet l4 og arbejdspunktet for kernen 1 forskydes, kræves der altså en større fejlvekselstrømsafledning fra apparatet 12 eller 13 eller begge, før relæet 10 reagerer, og disse apparater er altså ikke beskyttet så godt som forudset 20 i betragtning af den nominelle udløsnings-fejlvek-selstrøm In. Som et typisk tilfælde kan nævnes, at In er 30 milliampere, og at der fra apparatet 14 sker en jævnstrømsafledning på 1 ampere, og i så fald kræves der til udløsning en vekselfejlstrøm 25 på over 1 ampere i stedet for 30 milliampere. I et sådant tilfælde vil relæets beskyttelsesvirkning således være ødelagt. Særlig stor skaderisiko vil der være, hvis apparaterne er håndbetjente og ikke har en særlig jordledning, fx transportable apparater.It will be seen that the required residual current to. tripping of the trigger means increases sharply at the fault direct current Ide. Thus, when a residual direct current 15 is dissipated from the apparatus 14 and the operating point of the core 1 is shifted, a larger alternating current is dissipated from the apparatus 12 or 13 or both before the relay 10 reacts, and these apparatuses are thus not protected as well as provided in considering the rated tripping error current In. As a typical case, it can be mentioned that In is 30 milliamps, and that a direct current discharge of 1 ampere takes place from the apparatus 14, in which case an alternating fault current 25 of more than 1 ampere is required for tripping instead of 30 milliamps. In such a case, the protective effect of the relay will thus be destroyed. There will be a particularly high risk of damage if the devices are hand-operated and do not have a special earth cable, eg transportable devices.
3030
Det i fig. 5 viste fejlstrømsrelæ ifølge opfindelsen har ligeledes en ringformet magnetkerne 1 og en sekundærvikling 4, der er forbundet med et udløseorgan 5, som betjener afbrydere 6. Kernen 1 har imidlertid 35 ud over sekundærviklingen 4 en hjælpevikling 16, der 146609 9 1 er serieforbundet med en indgangsvikling 17 på en anden transformator, som har en ringformet magnet-kerne 18 og en anden vikling 19, der er serieforbundet med sekundærviklingen 4 og tjener som sammen-5 ligningssignalvikling og er forbundet med' udløseorganet 5 på en sådan måde, at de to viklinger 4 og 19 er i modfase. De to serieforbundne viklinger 16 og 17 forsynes med vekselstrøm, i det viste tilfælde ved forbindelse med to netledere gennem en mod-10 stand 20. De to netledere er forbundet med et eller flere ikke viste apparater, der skal beskyttes ved hjælp af fejlstrømsrelæet. De to netledere går gennem magnetkernen 1. Der er kun vist to netledere, men relæet vil virke på samme måde ved fire ledere 15 til et trefasenet.The device shown in FIG. 5 also has an annular magnetic core 1 and a secondary winding 4 connected to a tripping means 5 which actuates switches 6. However, in addition to the secondary winding 4, the core 1 has an auxiliary winding 16 which is connected in series with a input winding 17 on a second transformer having an annular magnetic core 18 and a second winding 19 connected in series with the secondary winding 4 and serving as a comparison signal winding and connected to the trigger means 5 in such a way that the two windings 4 and 19 are in opposite phase. The two series-connected windings 16 and 17 are supplied with alternating current, in the case shown by connecting two mains conductors through a resistor 20. The two mains conductors are connected to one or more devices (not shown) to be protected by means of the residual current current relay. The two mains conductors pass through the magnetic core 1. Only two mains conductors are shown, but the relay will work in the same way with four conductors 15 for a three-phase network.
Vekselstrømmen gennem de to viklinger 16 og 17 bevirker induktion af lige store vekselstrømme i viklingerne 4 og 19, men da disse viklinger er modkoblede, 20 bevirker dette intet signal til udløseorganet 5· Når der ikke sker afledning fra det eller de forbrugende apparater, vil strømmene i de to netledere være i balance, og der fremkommer intet signal til udløseorganet 5. Hvis der fremkommer en vekselstrøms-25 afledning og dermed en resulterende vekselstrøm gennem kernen, bevirker denne vekselstrøm en ændring af signalet fra sekundærviklingen 4, men ikke en ændring af signalet fra signalviklingen 19, og der fremkommer derfor et signal til udløsning af udløseren 5* Hvis 30 der fremkommer en jævnstrømsafledning og dermed en resulterende jævnstrømsmagnetisering af kernen 1, bevirker denne magnetisering en forskydning af arbejds-punktet for transformatoren 1, 4, 16, men ikke for transformatoren 17, 18, 19, og der fremkommer derfor 35 en forskel mellem signalerne fra sekundærviklingen 4 146609 10 1 og signalviklingen 19, så at der fremkommer et resulterende signal til udløsning af udløseren 5·The alternating current through the two windings 16 and 17 causes the induction of equal alternating currents in the windings 4 and 19, but since these windings are switched off, this causes no signal to the trigger means 5 · When there is no diversion from the consuming device (s), the currents in the two mains conductors be in balance and no signal is obtained to the trigger means 5. If an alternating current-lead and thus a resulting alternating current through the core is generated, this alternating current causes a change of the signal from the secondary winding 4, but not a change of the signal from the signal winding 19, and therefore a signal is obtained for tripping the trigger 5 * If a direct current discharge and thus a resulting direct current magnetization of the core 1 occurs, this magnetization causes a shift of the operating point of the transformer 1, 4, 16, but not for the transformer 17, 18, 19, and therefore a difference arises between the signals from the secondary winding 4 146 609 10 1 and the signal winding 19 so as to obtain a resultant signal for triggering the trigger 5 ·
Pen i fig. 6 viste modifikation svarer i hovedsagen 5 til det i fig. 5 viste fejlstrømsrelæ. De to kerner 1 og 18 er erstattet af en transformatorkerne, der har to åbninger 21 og 22 til dannelse af en trebenet kerne med to uafhængige fluxveje i benene 23 og 24, hvor sekundærviklingen 4 er anbragt på kernen 23, 10 medens signalviklingen 19 er anbragt på kernen 24.The pen in fig. The modification shown in Fig. 6 substantially corresponds to that in fig. 5 shows a residual current current relay. The two cores 1 and 18 are replaced by a transformer core having two openings 21 and 22 to form a three-legged core with two independent flux paths in the legs 23 and 24, the secondary winding 4 being arranged on the core 23, 10 while the signal winding 19 is arranged on the core 24.
De to viklinger 16 og 17 er erstattet af en enkelt vikling 25, der er anbragt på midterbenet og derfor er fælles for begge kerner. Viklingen 25 er gennem modstanden 20 forbundet med de to netledere, og 15 disse er ført gennem åbningen 21. Det i fig. 6 viste relæ fungerer i det væsentlige på samme måde som det i fig. 5 viste.The two windings 16 and 17 are replaced by a single winding 25 which is placed on the middle leg and is therefore common to both cores. The winding 25 is connected through the resistor 20 to the two mains conductors, and these are passed through the opening 21. The device shown in fig. 6 operates in substantially the same manner as that shown in FIG. 5 showed.
I stedet for to netledere.som vist i fig. 5 og 6 20 kan der være tre eller flere ledere. I stedet for at udtage vekselstrømmen til viklingerne 16 og 17 eller 25 direkte fra netledere gennem en modstand kan man udtage den gennem en transformator. Det vil også være muligt at anvende en vekselstrømskilde, der 25 er uafhængig af netlederne. I fig. 5 og 6 er det forudsat, at netlederne fører vekselstrøm. Det vil imidlertid også være muligt at benytte relæet til jævnstrøm, hvor netlederne ligeledes føres gennem magnetkernen 1 eller .23. I så fald kan der anvendes 30 en særskilt vekselstrømskilde til forsyning af viklingerne 16 og 17 eller 25, eller der kan anvendes en vekselstrømsgenerator, der fødes med jævnstrøm. Mellem viklingerne 4, 19 og udløseorganet 5 kan der være indskudt en forstærker.Instead of two mains conductors, as shown in FIG. 5 and 6 20 there may be three or more conductors. Instead of drawing the alternating current to the windings 16 and 17 or 25 directly from mains conductors through a resistor, you can draw it through a transformer. It will also be possible to use an AC power source which is independent of the mains conductors. In FIG. 5 and 6, it is assumed that the mains conductors carry alternating current. However, it will also be possible to use the relay for direct current, where the mains conductors are also passed through the magnetic core 1 or .23. In that case, a separate AC source may be used to supply the windings 16 and 17 or 25, or an AC alternator may be used. An amplifier may be inserted between the windings 4, 19 and the release means 5.
35 146609 11 1 Det i fig. 7 viste relæ har en sumstrømtransformator-kerne 1 med en sekundærvikling 4, hyi.s ene terminal er ført til et udløsningsorgan 5, medens den anden terminal er ført til den ene af de to netledere.146609 11 1 The device shown in FIG. 7 has a sum current transformer core 1 with a secondary winding 4, one terminal of which is led to a tripping means 5, while the other terminal is led to one of the two mains conductors.
5 Den anden terminal af udløsningsorganet 5 er ført til den anden netleder. På kernen 1 er der anbragt endnu en vikling 26, hvis to terminaler er forbundet med de to netledere. I viklingen 26 går der en konstant vekselstrøm, der gennem kernen 1 bevirker induktion 10 af en vekselspænding i viklingen 4, hvilken overlejres af den fra nettet afledede spænding i kredsen 4, 5.The second terminal of the trigger means 5 is led to the second mains conductor. A further winding 26 is arranged on the core 1, the two terminals of which are connected to the two mains conductors. In the winding 26 there is a constant alternating current which causes induction 10 of an alternating voltage in the winding 4 through the core 1, which is superimposed by the voltage derived from the mains in the circuit 4, 5.
De to viklinger 26 og 4 er fortrinsvis således afpasset, at der, når der ikke går fejlstrøm i de to netledere, ingen strøm går i kredsen 4, 5. Når der 15 fremkommer en vekselfejlstrøm i netlederne, vil der induceres en strøm i viklingen 4 til udløseorganet 5 og afbrydelse af afbryderne 6. Når der fremkommer en jævnstrømsfejlstrøm, vil arbejdspunktet for kernen 1 ændres, så at den vekselspænding, der fra viklingen 20 26 induceres i viklingen 4, ændres, så at der til udløsningsorganet 5 kommer et ændret signal til udløsning og dermed afbrydelse. De to kredse, henholdsvis 26 og 4, 5 kan eventuelt fødes fra en særlig generator. I så fald kan relæet benyttes til overvågning 25 af et jævnstrømsnet.The two windings 26 and 4 are preferably adjusted so that when there is no residual current in the two mains conductors, no current flows in the circuit 4, 5. When an alternating residual current occurs in the mains conductors, a current will be induced in the winding 4 to the tripping means 5 and disconnecting the switches 6. When a direct current fault current occurs, the operating point of the core 1 will change so that the alternating voltage induced from the winding 26 in the winding 4 changes so that a changed signal arrives at the tripping means 5. ejaculation and thus interruption. The two circuits, 26 and 4, 5, respectively, may be fed from a special generator. In that case the relay can be used for monitoring 25 of a direct current network.
Det i fig. 8 viste relæ har en sumtransformatorkerne 1 med en sekundærvikling 4 og et udløseorgan 5. Sekundærviklingen 4 er anbragt i en brokobling sammen med en 30 kondensator 27 og tre modstande 28, 29 og 30.The device shown in FIG. 8 has a sum transformer core 1 with a secondary winding 4 and a tripping means 5. The secondary winding 4 is arranged in a bridge coupling together with a capacitor 27 and three resistors 28, 29 and 30.
Udløseorganet 5 er anbragt i broen mellem koblingens to sider, medens en vekselstrømsgenerator 31 er forbundet med enderne af brokoblingen. Delene 4, 27, 28, 29 og 30 er fortrinsvis således dimensioneret, at der, 35 når der ikke går fejlstrøm i netlederne, vil fås nul- 146609 12 1 signal til udløseorganet 5- Vekselstrømmen gennem viklingen 4 bevirker vekselmagnetisering af kernen 1. Hvis der i netlederne går en vekselfejlstrøm, vil der i viklingen 4 induceres en vekselspænding, 5 som bevirker et fra nul forskelligt signal til udløseorganet 5· Hvis der i netlederne går en jævnstrømsfejlstrøm, bevirker denne en jævnmagnetisering af kernen 1, hvorved selvinduktionen for viklingen 4 formindskes, hvilket vil bevirke et fra nul forskel-10 ligt signal til udløseorganet 5. Relæet kan benyttes til overvågning af såvel et jævnstrømsnet som et vekselstrømsnet. Generatoren 31 kan eventuelt fødes fra nettet. Det vil også være muligt at udelade generatoren 31, når enderne af brokoblingen forbindes 15 med netlederne. Hvor der anvendes en særlig generator, kan denne være indrettet til at levere vekselstrøm med en frekvens, der kan være langt højere end frekvensen af nettet, fx flere gange så højt.The release means 5 is arranged in the bridge between the two sides of the coupling, while an alternator 31 is connected to the ends of the bridge coupling. The parts 4, 27, 28, 29 and 30 are preferably dimensioned in such a way that, when there is no residual current in the mains conductors, a zero signal will be obtained to the trigger means 5- The alternating current through the winding 4 causes alternating magnetization of the core 1. If an alternating current current flows in the mains conductors, an alternating voltage will be induced in the winding 4, which causes a signal different from zero to the tripping means 5 · If a direct current fault current flows in the mains conductors, this causes a direct magnetization of the core 1, whereby the self-induction of the winding 4 , which will cause a signal different from zero to the trip means 5. The relay can be used for monitoring both a direct current network and an alternating current network. The generator 31 can optionally be fed from the grid. It will also be possible to omit the generator 31 when the ends of the bridge coupling are connected 15 to the mains conductors. Where a special generator is used, this may be arranged to supply alternating current with a frequency which may be much higher than the frequency of the network, for example several times as high.
Claims (8)
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DK186268A DK146609C (en) | 1968-04-24 | 1968-04-24 | FAULT CURRENT RELAY |
| GB5783768A GB1255795A (en) | 1968-04-24 | 1968-12-05 | Earth leakage protection devices |
| DE19691905505 DE1905505C3 (en) | 1968-04-24 | 1969-02-05 | Residual current circuit breaker |
| FR6912857A FR2009835A1 (en) | 1968-04-24 | 1969-04-23 |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DK186268 | 1968-04-24 | ||
| DK186268A DK146609C (en) | 1968-04-24 | 1968-04-24 | FAULT CURRENT RELAY |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| DK146609B true DK146609B (en) | 1983-11-14 |
| DK146609C DK146609C (en) | 1984-04-30 |
Family
ID=8108614
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DK186268A DK146609C (en) | 1968-04-24 | 1968-04-24 | FAULT CURRENT RELAY |
Country Status (4)
| Country | Link |
|---|---|
| DE (1) | DE1905505C3 (en) |
| DK (1) | DK146609C (en) |
| FR (1) | FR2009835A1 (en) |
| GB (1) | GB1255795A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2555302C3 (en) * | 1975-12-09 | 1982-02-25 | Brown, Boveri & Cie Ag, 6800 Mannheim | Residual current protection circuit |
| DE2555221C2 (en) * | 1975-12-09 | 1984-10-25 | Brown, Boveri & Cie Ag, 6800 Mannheim | Procedure for the detection of residual currents of any kind |
| DE2555303C3 (en) * | 1975-12-09 | 1982-03-04 | Brown, Boveri & Cie Ag, 6800 Mannheim | Residual current circuit arrangement |
| DE2602534A1 (en) * | 1976-01-23 | 1977-07-28 | Siemens Ag | FAULT CURRENT CIRCUIT BREAKER |
| GB9016598D0 (en) * | 1990-07-27 | 1990-09-12 | Atomic Energy Authority Uk | Traction system earth fault protection |
| DE19534273A1 (en) * | 1995-09-15 | 1997-03-20 | Schupa Elektro Gmbh & Co Kg | Protection device for surge arresters |
| CN103368133B (en) * | 2012-03-28 | 2016-08-31 | 施耐德电器工业公司 | There is the earth leakage circuit breaker of low current fault protection between phase line |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE567079C (en) * | 1928-01-17 | 1933-01-03 | H Smolinski Dr Ing | Device for preventing the persistence of fault currents, for example in the event of earth faults in electrical systems |
| DE603108C (en) * | 1929-10-29 | 1934-09-22 | Siemens Schuckertwerke Akt Ges | Protection circuit with a relay lying in series with an overcurrent release, which closes its contacts when the permissible current limit is exceeded or not reached |
| DE521553C (en) * | 1929-12-21 | 1931-03-24 | Aeg | Current transformer for supplying tripping devices for overcurrent switches |
| DE1027297B (en) * | 1953-10-24 | 1958-04-03 | Licentia Gmbh | Current and current direction-dependent protection arrangement for electrical systems |
| DE1146181B (en) * | 1961-04-28 | 1963-03-28 | Siemens Ag | Residual current circuit breaker with summation current transformer and amplifier |
| DE1140275B (en) * | 1961-05-12 | 1962-11-29 | Vedder Gmbh Geb | Residual current protection circuit |
| DK151524C (en) * | 1984-02-23 | 1988-06-13 | Nordischer Maschinenbau | APPLICATION FOR OPENING THE BUGHOLE OF FISH |
-
1968
- 1968-04-24 DK DK186268A patent/DK146609C/en not_active IP Right Cessation
- 1968-12-05 GB GB5783768A patent/GB1255795A/en not_active Expired
-
1969
- 1969-02-05 DE DE19691905505 patent/DE1905505C3/en not_active Expired
- 1969-04-23 FR FR6912857A patent/FR2009835A1/fr not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| DE1905505B2 (en) | 1973-01-11 |
| GB1255795A (en) | 1971-12-01 |
| DE1905505A1 (en) | 1969-11-20 |
| DK146609C (en) | 1984-04-30 |
| FR2009835A1 (en) | 1970-02-13 |
| DE1905505C3 (en) | 1982-04-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PBP | Patent lapsed |