CN105785157A - Double main transformer longitudinal differential protection loop closing testing method - Google Patents
Double main transformer longitudinal differential protection loop closing testing method Download PDFInfo
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- CN105785157A CN105785157A CN201410850329.7A CN201410850329A CN105785157A CN 105785157 A CN105785157 A CN 105785157A CN 201410850329 A CN201410850329 A CN 201410850329A CN 105785157 A CN105785157 A CN 105785157A
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Abstract
The invention relates to a double main transformer longitudinal differential protection loop closing testing method. The method includes the following steps: a first step of determining that requirements for loop closing is satisfied; a second step of double main transformers conducting power transmission and phase checking; a third step of loop closing and adjusting shifts of transformers; a fourth step of testing a longitudinal differential protection system; a fifth step of finishing the test; if each item of data and parameter meet requirements for the longitudinal differential protection of the transformers, after testing data are recorded, gradually recovering the shifts of the transformer to an initial state, and finally disconnecting a bus tie circuit breaker, and recovering a differential protection trip-out pressure plate. According to the invention, the method guarantees that phase sequences of the two transformers in the newly built transformer substation are correct, and that first and secondary wiring and polarities of the longitudinal differential protection are correct, increases reliability and stability of main transform differential protection, simplifies testing procedures, and increases testing efficiency.
Description
Technical field
The present invention relates to a kind of double; two main transformer longitudinal differential protection cyclization method of testing.
Background technology
The double; two main transformer double-bus of the commonly used on-load voltage regulation of Chang Nei electric substation of large size industrial enterprise, and can the change distribution design of parallel running, main transformer arranges the relay protection measure such as longitudinal differential protection, standby current protection.For ensureing transformer and distribution power station after operation, excising fault rapidly and accurately, the test of the longitudinal differential protection of main transformer and debugging are one of most important work.
Method of testing general now is: after once connecting with secondary line and checking and terminate, and carries out intelligence and combines the differential protection test protected and have verified that the accuracy of definite value and protection, and the method can only be tested secondary circuit and primary circuit cannot be verified.
Using high-current generation device to produce the sufficiently large primary current correctness by transformer test differential lines, the method operation inconvenience, need step measurement, and can not measure the phase angle situation of first and second three-phase current, reliability is not high.
Further method is: use three-phase 380V low-tension supply to pass into main transformer high-pressure side, current transformer at main transformer low-pressure side bus is subsequently formed short circuit, by short circuit current and current transformer detect differential system once, the wiring of secondary and polarity whether correct.
Also all kinds of corrupt practices creep in when practical application for the method for testing of use low-tension supply manufacture short circuit current, and such as the material such as cable, switch, shorting stub need to meet the capacity requirement of short circuit current, it is possible to cannot smooth operation.Additionally, the current transformer of main transformer low-pressure side bus is generally arranged in power distribution cabinet, technology upgrading along with distribution high-voltage board, the inner space of power distribution cabinet is closely, want on the bus after this transformer, connect satisfactory short-circuit line extremely difficult, even needing to disassemble cabinet inner part (bus, transformer), such operation is not only wasted time and energy, and also has potential safety hazard.
Summary of the invention
It is contemplated that overcome the defect of prior art; a kind of double; two main transformer longitudinal differential protection cyclization method of testing is provided; ensure that the phase sequence of two main transformers of newly-built transformer station is correct; once and secondary connection is correct, polarity correct to ensure longitudinal differential protection, improves the reliability and stability of transform er differential protection；Simplify testing procedure, improve testing efficiency.
In order to solve above-mentioned technical problem, the present invention is achieved in that
1, a kind of double; two main transformer longitudinal differential protection cyclization method of testing, it is characterised in that it comprises the steps:
Step one: confirm to meet cyclization requirement
1) two cyclization main transformer models, capacity, connection group, gear number, transformation ratio etc. must be consistent, and short-circuit impedance differs less than 10%；
2) two main transformer primary voltages should be basically identical, and voltage difference is less than 10%, and two incoming powers should belong to same system；
3) higher level's stabilization of power grids meets the requirements prescribed；
4) the necessary phase place of two sections of buses of higher level's electrical network is identical, and voltage difference, carrier phase shift are less than 5%；
Step 2: double; two main transformers are by electricity and nuclear phase
1) all power supplying and distributing equipment pass the tests of transformer station, connect first and second loop, and transformer station is qualified by inspection, and higher level energy sector is agreed to by starting tissue after electricity application by electricity work；
2) perform the test of main transformer Switching impulse, cable charging, busbar charging etc. by electricity work, notice that two transformators should on same gear；
3) two sections of buses are by after electricity, need to carry out primary circuit nuclear phase at mother position in storehouse, it is ensured that two sections of bus wire phase sequences are consistent；And the voltage transformer secondary side for two sections of buses is also carried out phase sequence confirmation, consistent to ensure two sections of bus-bar potential transformer secondary phase sequences；
4) check the magnitude of voltage on two sections of buses by the voltage transformer of two sections of high-voltage boards of step down side, it is ensured that two transformators under identical gear low-pressure side voltage difference less than 5%；
Step 3: cyclization also adjusts transformer gear
1) ensureing that two main transformers are all located at same operation range N, exit main transformer differential protection trip pressing plate and retain fast differential over current protection, operation mother cabinet breaker closes a floodgate, and makes two sections of buses and parallel operation of transformers；
2) now two sections of busbar voltage differences are less than 5%, and on system line, circulation is less than 20A；Differential protection relay checks data the record such as the electric current of two transformators, difference stream, phase angle；Using six phase differential protection testers that transformator the superior and the subordinate Current Transformer Secondary side electric current carries out sampling test, the data such as Current Transformer Secondary side electric current, phase angle difference are recorded；
3) the first transformer main change gear is risen to N+1 by N, observe and record Alloy White Iron voltage and phase angles data；
4) as electric current is too little, it is impossible to judge, the second transformer main change gear is down to N-1 by N, observes and record Alloy White Iron voltage and phase angles data；
5) be repeated in above-mentioned 3), 4) make electric current gradually rise, when the current sampling data of protective relay exceedes differential starting current 1.5 times stop adjust gear position operation；
Step 4: longitudinal differential protection system test
1) check sampling and the warning message of the balanced relay of two main transformers, make vector diagram according to the amplitude of six road electric currents of upper and lower two groups of current transformers sampling, phase angle, and record the data such as difference stream, stalling current；
2) use six phase differential protection testers that transformator the superior and the subordinate Current Transformer Secondary side electric current carries out sampling test; sampling location can at the current input terminal of balanced relay backboard two-way current transformer; the vector diagram of six road electric currents of sampling can be directly displayed on instrument screen, and the data such as current amplitude, phase angle, difference stream all clearly show；
3) contrast above-mentioned 1) and 2) vector diagram, current amplitude, phase angle, the difference data such as stream; two numbers evidences should be consistent; meet this longitudinal differential protection system features; and difference stream is less than 0.01A; as abnormal conditions occur: difference stream more than 0.01A, three-phase imbalance, the superior and the subordinate's homophase phase angle difference more than 10%, differential protection action etc.; after must recording data, system recovery has a power failure to original state；Analyze measurement result, complete test by continuing above step after system correction；
Step 5: terminate test
As each item data, parameter meet the requirement of this transformer longitudinal linked differential protection, after record test data, progressively transformer gear is recovered to original state, finally by bus disjunction, recover differential protection trip pressing plate.
The invention has the beneficial effects as follows: this method of testing, without connecting cable on system line, access test power supply, installing and measure instrument, is disassembled, installed power supplying and distributing equipment.Save material, instrument puts into, and will not destroy power supplying and distributing equipment, and potential safety hazard is little；
Two kinds of collecting measurement data equipment that this method of testing uses: one, the differential protection relay that system carries, do not have secondary dismounting, dependable performance；Two, six phase differential protection tester, this equipment volume is little, current resolution 0.0001A, phase angular resolution 0.1 °, and certainty of measurement is high, need not change system original circuit during measurement.
This method of testing is easy and simple to handle; can be completed by electric process first in transformer station; and use formal supply line to complete test; avoid the potential safety hazard that unnecessary interim measurement circuit brings; disposable can completing the experimental projects such as transformator Switching impulse, nuclear phase, paired running, longitudinal differential protection test, work efficiency is obviously improved.
Accompanying drawing explanation
Below in conjunction with drawings and embodiments, the present invention is described in further detail:
Fig. 1 is double; two main transformer ring structures schematic diagrams.
Fig. 2 is the structural representation of six phase differential protection tester samplings.
Detailed description of the invention
As depicted in figs. 1 and 2: a kind of double; two main transformer longitudinal differential protection cyclization method of testings, step one is comprised the steps:: confirmation system meets cyclization requirement
1) two cyclization main transformer models, capacity, connection group, gear number, transformation ratio etc. must be consistent, and short-circuit impedance differs less than 10%；
2) two main transformer primary voltages should be basically identical, and voltage difference is less than 10%, and two incoming powers should belong to same system；
3) higher level's stabilization of power grids meets the requirements prescribed；
4) the necessary phase place of two sections of buses of higher level's electrical network is identical, and voltage difference, carrier phase shift are less than 5%；
Step 2: double; two main transformers are by electricity and nuclear phase
1) all power supplying and distributing equipment pass the tests of transformer station, first and second loop correctly connects after check and correction checks according to design drawing, and transformer station is qualified by inspection, and higher level energy sector is agreed to by starting tissue after electricity application by electricity work；
2) performed the test of main transformer Switching impulse, cable charging, busbar charging etc. by electricity work in strict accordance with transformer station by electricity scheme, notice that two transformators should on same gear；
3) two sections of buses are by after electricity, need to carry out primary circuit nuclear phase at mother position in storehouse, it is ensured that two sections of bus wire phase sequences are consistent.And the voltage transformer secondary side for two sections of buses is also carried out phase sequence confirmation, consistent to ensure two sections of bus-bar potential transformer secondary phase sequences；
4) check the magnitude of voltage on two sections of buses by the voltage transformer of two sections of high-voltage boards of step down side, it is ensured that two transformators under identical gear low-pressure side voltage difference less than 5%；
Step 3: cyclization also adjusts transformer gear
1) ensureing that two main transformers are all located at same operation range N, exit transform er differential protection trip pressing plate (protection act, but do not trip) and retain fast differential over current protection, operation mother cabinet breaker closes a floodgate, and makes two sections of buses and parallel operation of transformers；
2) now two sections of busbar voltage differences minimum (less than 5%), on system line, circulation is less than 20A(primary current).Differential protection relay checks data the record such as the electric current of two transformators, difference stream, phase angle.Using six phase differential protection testers that transformator the superior and the subordinate Current Transformer Secondary side electric current carries out sampling test, the data such as Current Transformer Secondary side electric current, phase angle difference are recorded；
3) the first transformator T1 main shift is risen to N+1 by N, observe and record Alloy White Iron voltage and phase angles data.
4) as electric current is too little, it is impossible to judge, the second transformator T2 main shift is down to N-1 by N, observes and record Alloy White Iron voltage and phase angles data.
5) be repeated in step 3), 4) make electric current gradually rise, when the current sampling data of protective relay exceedes differential starting current 1.5 times stop adjust gear position operation
Step 4: longitudinal differential protection system test
1) check sampling and the warning message of the balanced relay of two main transformers, make vector diagram according to the amplitude of six road electric currents of upper and lower two groups of current transformers sampling, phase angle, and record the data such as difference stream, stalling current；
2) use six phase differential protection testers 3 that transformator the superior and the subordinate Current Transformer Secondary side electric current carries out sampling test; sampling location is as shown in Figure 2; can at the current input terminal of balanced relay backboard two-way current transformer; the vector diagram of six road electric currents of sampling can be directly displayed on instrument screen, and the data such as current amplitude, phase angle, difference stream all clearly show；Number in the figure 4 is high-pressure side three-phase current sampled point, and number in the figure 5 is low-pressure side three-phase current sampled point.
3) contrast step 1) and 2) vector diagram, current amplitude, phase angle, differ from the data such as stream; two numbers evidences should be consistent; meet this longitudinal differential protection system features; and difference stream should be zero (less than 0.01A); as abnormal conditions occur: difference stream is more than 0.01A, three-phase imbalance, the superior and the subordinate's homophase phase angle difference nonconforming (error is more than 10%), differential protection action etc.; after must recording data, system recovery has a power failure to original state.Analyze measurement result, complete test by continuing above step after system correction.
Step 5: terminate test
As each item data, parameter meet the requirement of this transformer longitudinal linked differential protection, after record test data, progressively transformer gear is recovered to original state, finally by bus disjunction, recover differential protection trip pressing plate；
This method is based on the change distribution design of commonly used two same models of newly-built transformer station, the on-load voltage regulation type main transformer of same specification, the low-pressure side of two main transformers is respectively connected to two sections of high-voltage boards of transformer station through bus or cable, when ensureing to meet cyclization condition, two sections of buses of high-voltage board can connect mother cabinet breaker to realize parallel running, both cyclizations.
The gear of main transformer is adjusted by on-load voltage regulating device, two main transformer low-pressure sides there will be voltage difference, produces circulation, progressively adjust the gear of two main transformers on low-pressure side bus, make the circulation on bus incrementally increase, after current value meets test request, stop gear adjustment.
This test is by the double sampling value of transform er differential protection relay, warning message; and six measurement data of phase differential protection tester; comprehensive descision differential protective system once, secondary connection, polarity, phase angle difference, difference stream etc. whether correct, if can stable operation.
Claims (1)
1. a double; two main transformer longitudinal differential protection cyclization method of testing, it is characterised in that it comprises the steps:
Step one: confirm to meet cyclization requirement
1) two cyclization main transformer models, capacity, connection group, gear number, transformation ratio etc. must be consistent, and short-circuit impedance differs less than 10%；
2) two main transformer primary voltages should be basically identical, and voltage difference is less than 10%, and two incoming powers should belong to same system；
3) higher level's stabilization of power grids meets the requirements prescribed；
4) the necessary phase place of two sections of buses of higher level's electrical network is identical, and voltage difference, carrier phase shift are less than 5%；
Step 2: double; two main transformers are by electricity and nuclear phase
1) all power supplying and distributing equipment pass the tests of transformer station, connect first and second loop, and transformer station is qualified by inspection, and higher level energy sector is agreed to by starting tissue after electricity application by electricity work；
2) perform the test of main transformer Switching impulse, cable charging, busbar charging etc. by electricity work, notice that two transformators should on same gear；
3) two sections of buses are by after electricity, need to carry out primary circuit nuclear phase at mother position in storehouse, it is ensured that two sections of bus wire phase sequences are consistent；And the voltage transformer secondary side for two sections of buses is also carried out phase sequence confirmation, consistent to ensure two sections of bus-bar potential transformer secondary phase sequences；
4) check the magnitude of voltage on two sections of buses by the voltage transformer of two sections of high-voltage boards of step down side, it is ensured that two transformators under identical gear low-pressure side voltage difference less than 5%；
Step 3: cyclization also adjusts transformer gear
1) ensureing that two main transformers are all located at same operation range N, exit main transformer differential protection trip pressing plate and retain fast differential over current protection, operation mother cabinet breaker closes a floodgate, and makes two sections of buses and parallel operation of transformers；
2) now two sections of busbar voltage differences are less than 5%, and on system line, circulation is less than 20A；Differential protection relay checks data the record such as the electric current of two transformators, difference stream, phase angle；Using six phase differential protection testers that transformator the superior and the subordinate Current Transformer Secondary side electric current carries out sampling test, the data such as Current Transformer Secondary side electric current, phase angle difference are recorded；
3) the first transformer main change gear is risen to N+1 by N, observe and record Alloy White Iron voltage and phase angles data；
4) as electric current is too little, it is impossible to judge, the second transformer main change gear is down to N-1 by N, observes and record Alloy White Iron voltage and phase angles data；
5) be repeated in above-mentioned 3), 4) make electric current gradually rise, when the current sampling data of protective relay exceedes differential starting current 1.5 times stop adjust gear position operation；
Step 4: longitudinal differential protection system test
1) check sampling and the warning message of the balanced relay of two main transformers, make vector diagram according to the amplitude of six road electric currents of upper and lower two groups of current transformers sampling, phase angle, and record the data such as difference stream, stalling current；
2) use six phase differential protection testers that transformator the superior and the subordinate Current Transformer Secondary side electric current carries out sampling test; sampling location can at the current input terminal of balanced relay backboard two-way current transformer; the vector diagram of six road electric currents of sampling can be directly displayed on instrument screen, and the data such as current amplitude, phase angle, difference stream all clearly show；
3) contrast above-mentioned 1) and 2) vector diagram, current amplitude, phase angle, the difference data such as stream; two numbers evidences should be consistent; meet this longitudinal differential protection system features; and difference stream is less than 0.01A; as abnormal conditions occur: difference stream more than 0.01A, three-phase imbalance, the superior and the subordinate's homophase phase angle difference more than 10%, differential protection action etc.; after must recording data, system recovery has a power failure to original state；Analyze measurement result, complete test by continuing above step after system correction；
Step 5: terminate test
As each item data, parameter meet the requirement of this transformer longitudinal linked differential protection, after record test data, progressively transformer gear is recovered to original state, finally by bus disjunction, recover differential protection trip pressing plate.
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| CN107329016A (en) * | 2017-07-20 | 2017-11-07 | 中国三冶集团有限公司 | A kind of novel transformer group and current phase experimental bench and experimental method |
| CN108321800A (en) * | 2018-02-09 | 2018-07-24 | 国网上海市电力公司 | A kind of Alloy White Iron acquisition methods based on 10 kilovolts of busbar voltage vectors |
| CN110568249A (en) * | 2019-10-18 | 2019-12-13 | 国网江苏省电力有限公司盐城供电分公司 | parallel power transformer monitoring system based on circulating current detection and monitoring method thereof |
| CN111007439A (en) * | 2019-12-24 | 2020-04-14 | 深圳供电局有限公司 | Transformer substation bus protection secondary circuit commissioning on-load test method |
| CN111521887A (en) * | 2020-05-07 | 2020-08-11 | 西安热工研究院有限公司 | 380V power supply-based high-voltage station service power supply nuclear phase system and method |
| CN111521888A (en) * | 2020-05-07 | 2020-08-11 | 西安热工研究院有限公司 | High-voltage station bus power supply phase checking system and method |
| CN113325236A (en) * | 2021-07-02 | 2021-08-31 | 山东钢铁股份有限公司 | Power transmission phase checking method for double-bus double-section wiring GIS cabinet power supply |
| CN113820630A (en) * | 2021-08-13 | 2021-12-21 | 中石化南京工程有限公司 | Differential belt load test method for gear shifting of 110kV transformer |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110568249A (en) * | 2019-10-18 | 2019-12-13 | 国网江苏省电力有限公司盐城供电分公司 | parallel power transformer monitoring system based on circulating current detection and monitoring method thereof |
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| CN111007439B (en) * | 2019-12-24 | 2022-07-12 | 深圳供电局有限公司 | Transformer substation bus protection secondary circuit commissioning on-load test method |
| CN111521888A (en) * | 2020-05-07 | 2020-08-11 | 西安热工研究院有限公司 | High-voltage station bus power supply phase checking system and method |
| CN111521887B (en) * | 2020-05-07 | 2022-06-07 | 西安热工研究院有限公司 | 380V power supply-based high-voltage station service power supply nuclear phase system and method |
| CN111521888B (en) * | 2020-05-07 | 2022-07-08 | 西安热工研究院有限公司 | High-voltage station bus power supply phase checking system and method |
| CN111521887A (en) * | 2020-05-07 | 2020-08-11 | 西安热工研究院有限公司 | 380V power supply-based high-voltage station service power supply nuclear phase system and method |
| CN113325236A (en) * | 2021-07-02 | 2021-08-31 | 山东钢铁股份有限公司 | Power transmission phase checking method for double-bus double-section wiring GIS cabinet power supply |
| CN113820630A (en) * | 2021-08-13 | 2021-12-21 | 中石化南京工程有限公司 | Differential belt load test method for gear shifting of 110kV transformer |
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