SE424031B - SET TO OPEN 100% STATOR EARTH CLOSE PROTECTION FOR BLOCK CONNECTOR GENERATORS AND DEVICE FOR IMPLEMENTATION OF THESE SETS - Google Patents
SET TO OPEN 100% STATOR EARTH CLOSE PROTECTION FOR BLOCK CONNECTOR GENERATORS AND DEVICE FOR IMPLEMENTATION OF THESE SETSInfo
- Publication number
- SE424031B SE424031B SE7801944A SE7801944A SE424031B SE 424031 B SE424031 B SE 424031B SE 7801944 A SE7801944 A SE 7801944A SE 7801944 A SE7801944 A SE 7801944A SE 424031 B SE424031 B SE 424031B
- Authority
- SE
- Sweden
- Prior art keywords
- voltage
- support
- ground
- protection
- multiplier
- Prior art date
Links
Classifications
-
- 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
- H02H3/16—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 fault current to earth, frame or mass
- H02H3/17—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 fault current to earth, frame or mass by means of an auxiliary voltage injected into the installation to be protected
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/06—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric generators; for synchronous capacitors
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Ac-Ac Conversion (AREA)
- Tests Of Circuit Breakers, Generators, And Electric Motors (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Measurement Of Current Or Voltage (AREA)
Description
7801944-5 dyra stödtransformatorer. b) Uv är en spänning med en från driftfrekvensen avvikande frekvens. 7801944-5 expensive auxiliary transformers. b) Uv is a voltage with a frequency deviating from the operating frequency.
För att hålla inverkan av generator-jordkapacitansen låg, väljs därvid frekæmslmellan 10 och 20 Hz. Metoden har den fördelen att mätningen i hög grad är oberoende av störstorheter, så att amplituden hos Uv kan väljas mycket låg. En nackdel är emellertid att alstringen av stödspänningen Uv ierfordrar en dyr förstärkare.To keep the effect of generator-ground capacitance low, select thereby frequency between 10 and 20 Hz. The method has that advantage that the measurement is largely independent of quantities, so that the amplitude of Uv can be selected very low. However, a disadvantage is that the generation of the support voltage Uv requires an expensive amplifier.
Skulle mot förmodan den valda frehæmseluppträda i generatornoll- grenen, så träder reläet felaktigt i funktion. För att undvika detta tidskodas den lågfrekventa spänningen Uv dessutom (t.ex. några perioder genomsläpp och några perioder spärrning). Genom kodningen undviks visserligen en felutlösning, men man erhåller den nackdelen att reläet vid uppträdande av en störspänning med Uv-frekvensen blockeras, dvs. blir funktionsodugligtvid ett fel.Should, contrary to expectation, the selected brake act in the generator zero branch, the relay malfunctions. To avoid in this case, the low-frequency voltage Uv is also time-coded (e.g. some periods of passage and some periods of blocking). Through the coding is admittedly an error trigger is avoided, but one obtains the disadvantage that the relay in the event of a disturbance voltage with The UV frequency is blocked, ie. becomes inoperable in the event of a fault.
Uppfinningen har till syfte att eliminera nackdelarna hos de kända lösningarna och kombinera deras fördelar. Detta uppnås enligt upp- finningen därigenom att den driftfrekventa stödspänningens fas till uppnående av en sorts fassvängning kopplas varaktigt fram och till- baka mellan två lägen. I regel är dessa lägen ömesidigt motfasiga.The object of the invention is to eliminate the disadvantages of the known ones solutions and combine their benefits. This is achieved according to finding by the phase of the operating frequency of the support voltage to achieving a kind of phase oscillation is permanently coupled forward and bake between two positions. As a rule, these positions are mutually opposite.
Uppfinningen skall nu beskrivas närmare nedan med hänvisning till ritningarna på vilka fig. l visar den kända principen för en enkel spänningsmätning mellan generatorns stjärnpunkt och jord, fig. 2 åskådliggör funktionsprincipen för ett fassvängningselement, som enligt uppfinningen användes för alstring av en stödspänning, fig. 3 visar två faslägen hos denna stödspänning, samt fig. 4 visar fassvängningselementets anslutning till en generator-transformator- blockkoppling.The invention will now be described in more detail below with reference to the drawings in which Fig. 1 shows the known principle of a simple voltage measurement between the generator's star point and earth, fig. 2 illustrates the operating principle of a phase oscillating element, which according to the invention is used for generating a support voltage, Fig. 3 shows two phase positions of this support voltage, and Fig. 4 shows the connection of the phase oscillating element to a generator-transformer block coupling.
I fig. 1 visas den kända principen för en enkel spänningsmätning mellan en generators stjärnpunkt och jord, varvid mtan användning av stödspänning) 95% av lindningslängden, mätt från klämmorna till stjärnpunkten, skyddas. Medelst en stödspänning Uv, tillförd via en transformator W, stöds stjärnpunkten mot jord, och därigenom uppnås skyddstekniskt de återstående 5%. E är ar jordníngsmotstånd och U7* betyder den maximala spänningsmätningen.Fig. 1 shows the known principle for a simple voltage measurement between a generator's star point and earth, where mtan use of support voltage) 95% of the winding length, measured from the terminals to star point, protected. By means of a support voltage Uv, supplied via a transformer W, the star point is supported against earth, and thereby technically, the remaining 5% is achieved. E is a grounding resistor and U7 * means the maximum voltage measurement.
I fig. 2 åskådliggörs funktionsprincipen hos ett enligt uppfinningen 7801944-5 för alstring av en stödspänning föreslaget fassvängningselement.Fig. 2 illustrates the operating principle of one according to the invention 7801944-5 for generating a support voltage proposed phase oscillation element.
Skyddsobjektet (här ett nät 1) stöds via ett begränsningsmotstånd 2 med hjälp av en transformator 3 gentemot jord. Stödspänningen Uv erhålles från en driftfrekvent källa 4. Stödtransformatorn 3 har två primärlindningar 5 och 6, vilka via två triaker 7 och 8 är anslutningsbara till källan 4. En oscillator 9 öppnar omväx- lande triakerna 7 och 8 med en frekvens l/tl, så att stödspänningens UV fasläge alltid vrids med samma frekvens. Inv är en inverterare för uppnående av de riktiga styrsignalfaserna. I fig. 3 har de två faslägena hos Uv betecknats med Uvl och Uvz. Vid ett isola- tionsfel i skyddsobjektet 1 flyter en från Uv härrörande ström Iv (Ivl, Ivz i fig. 3) genom begränsningsmotståndet 2 och alstrar där ett spänningsfall. Detta spänningsfall tillföres via en isolertrans- formator 12 en multiplikators ll ingång x. Vid nultmflikauningåmyflzy erhålles som referenssignal själva spänningen Uv. För att undvika inverkningar av störströmmar över stödtransformatorns impedanser, kan referenssignalen även alstras separat synkront. Detta är fallet i fig. 2, där referenssignalgeneratorn är framställd med oscillatorn i ett enda block 9. Mätströmmen genom motståndet 2 består av en nytto- signal Iv och en odefinierbar störsignal Is. Is kan ha godtycklig frekvens, fasläge och, inom vissa gränser, även amplituder. Produk- ten vid multiplikatorns ll utgång är B=Uv x (Iv+Is)=Uv ' Tv + Uv - Is.The protection object (here a network 1) is supported via a limiting resistor 2 by means of a transformer 3 to ground. The support voltage Uv is obtained from an operating frequency source 4. The support transformer 3 has two primary windings 5 and 6, which via two triacs 7 and 8 are connectable to the source 4. An oscillator 9 opens triaxes 7 and 8 with a frequency l / tl, so that the support voltage UV phase mode is always rotated with the same frequency. Inv is an inverter to achieve the correct control signal phases. In Fig. 3 they have two phase positions at Uv are denoted by Uvl and Uvz. In the case of an error in the protection object 1 flows a current Iv (Ivl, Ivz in Fig. 3) through the limiting resistor 2 and generates there a voltage drop. This voltage drop is applied via an insulator formator 12 a multiplier ll input x. At nultm fl ikauningåmy fl zy is obtained as a reference signal the actual voltage Uv. To avoid effects of interference currents over the impedances of the support transformer, the reference signal can also be generated separately synchronously. This is the case in Fig. 2, where the reference signal generator is made with the oscillator in a single block 9. The measuring current through the resistor 2 consists of a useful signal Iv and an indefinable interference signal Is. Ice can have arbitrary frequency, phase position and, within certain limits, also amplitudes. Product ten at the output of the multiplier ll is B = Uv x (Iv + Is) = Uv 'Tv + Uv - Is.
Andelen Uv Is är vid integration över en godtyckligt lång tid tg lika med O.The proportion of Uv Ice is at integration over an arbitrarily long time tg equal to O.
Därigenom finns det vid motståndet 2 en möjlighet att skilja mellan nyttoströmmen Iv, som endast kan flyta vid ett fel, och alkamöjliga störströmmar Is. Integrationen sker vid filtret 13.Thereby, at the resistor 2, there is a possibility to distinguish between the payload current Iv, which can only flow in the event of a fault, and alkali possible storm currents Is. The integration takes place at the filter 13.
Vid en försöksprototyp befanns följande värden vara gynnsamma: Uv = 2% av nätfasspänningen tl = 60 ms, varvid triakerna endast tänds under 45 ms och övriga 15 ms tjänar som säkerhetstid för att undvika samtidig tändning av båda triakcrna genom störströmmar 13 = filter 12. Ordning (f*50dB) Fig. 4 visar fassvängningselementets anslutning till generator- transformatorblockkopplingen 1. Stödet erhålles över den i form av en öppen triangel kopplade spänningstransformatorn 14 med unge- 7801944-5 fär 2% av fasspänningen. Vid ett jordfel, t.ex. vid stället l5, sjunker impedansen vid spänningstransformatorns sekundärsida så djupt att nyttoströmmen Iv kan flyta över motståndet 2 och där mätas. Samtliga störströmmar genom motståndet 2, inklusive de, S0m framkallas genom själva jordslutningen, utfiltreras genom typen av mätmetod. För att hålla kopplingsuppbådet och -kostnaderna för multiplikatorn och det därpå följande filtret inom vissa gränser, kan från Is=0,5 ' If max omkoppling ske till en enkel driftfrekvent mätning av samma typ som för det normala 95%-iga statorjordslutnings- skyddet, varvid If (fig. 4) är felströmmen mot jord.In an experimental prototype, the following values were found to be favorable: Uv = 2% of the mains phase voltage tl = 60 ms, the triacs only igniting for 45 ms and the other 15 ms serve as security time to avoid simultaneous ignition of both triacs by interfering currents 13 = filter 12. Order (f * 50dB) Fig. 4 shows the connection of the phase oscillation element to the generator transformer block coupling 1. The support is obtained over it in shape of an open triangle connected the voltage transformer 14 with approx. 7801944-5 receives 2% of the phase voltage. In the event of a ground fault, e.g. at place l5, the impedance at the secondary side of the voltage transformer drops so deep that the payload current Iv can flow over the resistor 2 and there measured. All interference currents through resistor 2, including those, S0m is induced by the earth slope itself, filtered out by the type of measurement method. To keep the connection line-up and costs for the multiplier and the subsequent filter within certain limits, can from Is = 0.5 'If max switching takes place to a simple operating frequency measurement of the same type as for the normal 95% stator grounding the protection, where If (fig. 4) is the residual current to earth.
Den vid lösningen enligt uppfinningen använda, fasvarierande stöd- spänningen Uv kombinerar fördelarna hos båda de ovannämnda, konven- tionella metoderna a och b. Stödspänningen Uv är driftfrekvent och kan lätt alstras, vilket även är fallet vid metoden a. Å andra sidan kan amplituden hos Uv i överensstämmelse med metoden b göras relativt liten.The phase-varying support used in the solution according to the invention voltage Uv combines the advantages of both of the above, conventional national methods a and b. The support voltage Uv is operating frequency and can be easily generated, which is also the case with the method a. On the other hand then the amplitude of Uv can be made in accordance with method b relatively small.
Claims (10)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH254777A CH615536A5 (en) | 1977-03-01 | 1977-03-01 | Method for achieving 100% stator earth fault protection for a generator in unit connection |
Publications (2)
Publication Number | Publication Date |
---|---|
SE7801944L SE7801944L (en) | 1978-09-02 |
SE424031B true SE424031B (en) | 1982-06-21 |
Family
ID=4236244
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
SE7801944A SE424031B (en) | 1977-03-01 | 1978-02-20 | SET TO OPEN 100% STATOR EARTH CLOSE PROTECTION FOR BLOCK CONNECTOR GENERATORS AND DEVICE FOR IMPLEMENTATION OF THESE SETS |
Country Status (5)
Country | Link |
---|---|
CH (1) | CH615536A5 (en) |
DE (1) | DE2712975A1 (en) |
FI (1) | FI67977C (en) |
GB (1) | GB1601235A (en) |
SE (1) | SE424031B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AT401442B (en) * | 1993-06-18 | 1996-09-25 | Elin Energieversorgung | DEVICE FOR PROTECTING THE STAND STANDING FROM A SYNCHRONOUS MACHINE |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1463574B1 (en) * | 1964-01-18 | 1970-06-04 | Siemens Ag | Earth fault protection device for alternating or three-phase systems that are galvanically separated from the mains |
-
1977
- 1977-03-01 CH CH254777A patent/CH615536A5/en not_active IP Right Cessation
- 1977-03-24 DE DE19772712975 patent/DE2712975A1/en active Granted
-
1978
- 1978-02-13 GB GB5678/78A patent/GB1601235A/en not_active Expired
- 1978-02-20 FI FI780550A patent/FI67977C/en not_active IP Right Cessation
- 1978-02-20 SE SE7801944A patent/SE424031B/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
FI780550A (en) | 1978-09-02 |
DE2712975A1 (en) | 1978-09-07 |
SE7801944L (en) | 1978-09-02 |
CH615536A5 (en) | 1980-01-31 |
DE2712975C2 (en) | 1987-01-29 |
FI67977C (en) | 1985-06-10 |
GB1601235A (en) | 1981-10-28 |
FI67977B (en) | 1985-02-28 |
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