CN102095958A - Method for analyzing wiring correctness of double-winding conventional transformer single-switch differential protection CT - Google Patents
Method for analyzing wiring correctness of double-winding conventional transformer single-switch differential protection CT Download PDFInfo
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- CN102095958A CN102095958A CN2009103114925A CN200910311492A CN102095958A CN 102095958 A CN102095958 A CN 102095958A CN 2009103114925 A CN2009103114925 A CN 2009103114925A CN 200910311492 A CN200910311492 A CN 200910311492A CN 102095958 A CN102095958 A CN 102095958A
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Abstract
The invention relates to a method for analyzing the wiring correctness of a double-winding conventional transformer single-switch differential protection current transformer (CT), in particular to an analysis method for analyzing and judging whether the wiring of the CT of a double-winding conventional transformer single-switch differential protection circuit in an electric system is correct or not, and giving an error position and an error type. In order to solve the problems that the wiring error condition of a relay protection circuit is artificially judged in a time-consuming and labor-consuming mode, and the requirement on working personnel is high at present, the invention provides a method for analyzing the wiring of the conventional transformer differential protection circuit of the electric relay protection circuit, which has high judgment analysis reliability and is safely and simply used and convenient to operate.
Description
Technical field
The present invention relates to the many single differential protecting CT wiring correctness analytical approachs of closing of a kind of two winding conventional transformers, whether promptly a kind of wiring to the current transformer CT of the differential protection circuit of two winding conventional transformer list switches in the electric system is correctly carried out analysis and judgement and is provided errors present and the analytical approach of type of error.
Background technology
For the wiring in single CT loop, it is satisfied differ 120 ° between phase and phase, be positive sequence or negative phase-sequence, phase sequence is identical, each phase current two sub-value is identical simultaneously.It is identical with the primary current value in measurement loop that the current effective value of measuring according to secondary multiply by the primary current value that the CT transformation-ratio meter calculates.When wiring error, correct vector and actual measurement vectorial inequality compared with the correct vector plot that the measurement loop analysis draws according to the phasor graph of actual measurement and can be judged the place of wiring error.
Three kinds of basic conditions are generally arranged under the situation of wiring error, and one for the polarity of certain phase connects instead, is connected into negative drawing as just drawing, and will cause 180 ° of the phase phasic differences of electric current like this; Two is wrong between certain two-phase, and to the B phase, the misconnection of B phase will cause the phase sequence mistake of electric current like this to the A phase as the misconnection of A phase; Three be the CT no-load voltage ratio of certain phase, certain two-phase or three-phase with wrong, thereby cause the vector of mains side and load side and non-vanishing, the spill current increase can cause differential protection malfunction.For the conventional transformer differential protection, calculate the resultant vector of each phase of mains side and the resultant vector of each phase of load side.When each winding all satisfies the phase angle balance, promptly differ 120 ° between phase and phase, and phase sequence is identical, be positive sequence or negative phase-sequence.Simultaneously mains side and load side every mutually vector and when being zero, promptly amplitude equates, to differ 180 ° be that decidable conventional transformer differential protecting CT circuit connection is correct to angle.
The correctness of relay protection of power system CT circuit connection directly influences the normal operation of electric power system.The correctness of relay protection CT circuit connection is in time made analysis, judged; requisite important step during to be that transformer station is newly-built put into operation, overhaul; relay protection of power system CT circuit connection correctness is analyzed at present; main by manually carrying out Zhao especially main transformer, bus differential protecting CT loop; the staff will pass through a large amount of calculating; manual drawing current vector figure, and then draw the analysis result of relay protection CT circuit connection correctness according to result of calculation and vector plot.The The whole analytical process calculated amount is big, and needs the staff rule of thumb to judge, so there is the shortcoming that efficient is low, error is big.The flow process that the tradition manual method is analyzed relay protection CT circuit connection correctness is as follows:
Obtain data: the current amplitude, phase data and the correlation parameter that obtain each each phase of winding of conventional transformer differential protecting CT loop.Generally obtain (as using two pincers volt-ampere phase meters), the measured value of current amplitude, phase data and the measurement loop measured is compared, judge the correctness of single CT circuit connection by power measuring instrument.For two circle main transformers, use two pincers volt-ampere phase meters measure successively each phase (A, B, C, N) current amplitude of high-pressure side CT and low-pressure side CT and phase place and with compared by situation to determine the correctness of each side CT circuit connection according to meritorious, idle the sending of measuring the loop; Calculate electric current: calculate the coefficient of balance of each side earlier according to rated voltage and CT no-load voltage ratio, and then current amplitude is converted according to coefficient of balance; Adjust phase place: current phase is adjusted according to the mode of connection; Draw vector plot: according to parameter manual drawing vector plots such as reference voltage, current amplitude, phase angles; Analysis and judgement: judge CT circuit connection correctness according to each side through current value after the EQUILIBRIUM CALCULATION FOR PROCESS and vector plot, if wiring error needs profiling error reason and correcting method.Judge according to the pacing items that mains side resultant vector and load side resultant vector should equal and opposite in directions, direction is opposite whether whole differential circuit wiring is correct.
Operating personnel should be familiar with the electric system knowwhy, and will possess rich practice experience, and whether can judge relay protection CT circuit connection correct, analyze then and where make mistakes, how to revise; The manual method of traditional relay protection circuit wiring analysis exists following shortcoming or deficiency: work complexity height, inefficiency; Especially the data computation amount is big in the main transformer differential CT loop analysis deterministic process, and the manually-operated inefficiency is wasted time and energy, and in complicated operations flow process and lot of data computation process, makes a mistake unavoidably.Analysis result reliability and poor accuracy; Owing to there is not unified working specification, there is certain randomness in operation; In addition, the height of staff's professional skill, objective environment factor etc. all can impact analysis, the accuracy of judgement.Professional ability to operating personnel requires high.
Summary of the invention
The invention provides a kind of discriminatory analysis reliability height, two simple, easy to operate winding conventional transformer list switch differential protecting CT wiring correctness analytical approachs safe in utilization.
Technical solution of the present invention is:
The many single differential protecting CT wiring correctness analytical approachs of closing of two winding conventional transformers, this method may further comprise the steps: according to obtaining correct instantaneous meritorious, idle in this loop and send, be subjected to situation from measuring methods such as loop or the calculating of bus electric quantity balancing; According to the situation that is subjected to of sending of instantaneous meritorious, capacity of idle power, all is to be that reference voltage calculates correct phasing degree automatically with Ua generally; Draw correct vector relations according to the correct phasing degree that calculates; The phasing degree of this loop protection of actual measurement CT loop A, B, C phase, there is error at the phasing degree of actual measurement with the phasing degree that calculates according to the measurement loop, the phasing degree of protection CT loop A, B, C phase will deduct according to measuring the phasing degree that the loop calculates, and judges the correctness of this protection CT circuit connection; Export the judged result of single protection CT circuit connection correctness; Carry out the judgement of the CT circuit connection correctness of each side of main transformer according to the method described above successively; After the judgement of the CT circuit connection correctness of finishing each side, adopt the simultaneously-measured method of each side homophase to judge the correctness of each side CT composite vector of conventional transformer differential protection; The facies analysis result is closed in output.
The above relay protection of power system CT circuit connection analytical approach also comprised before step 7): obtain conventional transformer differential protecting CT loop measured value and parameter: conventional transformer differential protecting CT loop measured value and parameter comprise: the current effective value of each winding and phase place, the mode of connection of conventional transformer, each winding CT no-load voltage ratio, each winding rated voltage, each winding is meritorious, the idle electric situation that is subjected to of sending, the main electrical scheme situation, whether pass through the corresponding switch number of secondary connection adjustment and each winding; According to the conventional transformer parameter conventional transformer differential protecting CT loop measured value is converted, its specific implementation is: the coefficient of balance that calculates each winding of conventional transformer; According to the convert current effective value of this winding of the coefficient of balance of each winding of conventional transformer; It is the phase power angle of reference that all current phases are deducted with the measurement loop; Judge whether reference voltage is Ua; After then reference voltage being converted to Ua; If conventional transformer differential protecting CT loop is analyzed, then to carry out causing the compensation of each side primary current phase difference owing to the difference of a winding connection mode of each side of conventional transformer, preserve parameter and execution in step 7 after converting then).
The above step 6) adopts the simultaneously-measured method of each side homophase to close phase, and the reference vector of closing phase is that the side with the load current maximum that records in each side of conventional transformer is a benchmark, and the vector of other each side compares with it after closing mutually.
The analysis result that generates in the above step 7) is: wiring is correct, wiring error.
Advantage of the present invention is:
The analytical approach in the relay protection of power system CT loop that invention is provided is carried out twice analysis; judge at each CT loop and the differential CT of conventional transformer loop; can provide perfect wiring error situation and correction scheme in the final analysis result that forms; need not again the people for judging; its analysis result reliability obviously analytical approach than traditional is strong; and not influenced by aspects such as subjective quality of staff and objective environment factor, make precision of analysis significantly improve.
Embodiment
This method may further comprise the steps:
1) according to obtaining correct instantaneous meritorious, idle in this loop and send, be subjected to situation from measuring methods such as loop or the calculating of bus electric quantity balancing;
2) according to the situation that is subjected to of sending of instantaneous meritorious, capacity of idle power, all is to be that reference voltage calculates correct phasing degree automatically with Ua generally;
3) draw correct vector relations (generally being to reach positive sequence clockwise) according to the correct phasing degree that calculates;
4) phasing degree of this loop protection of actual measurement CT loop A, B, C phase; because there is error at the phasing degree of actual measurement with the phasing degree that calculates according to the measurement loop; so we consider that the phasing degree of real protection CT loop A, B, C phase will deduct according to measuring the phasing degree that the loop calculates, and judges the correctness of this protection CT circuit connection then.For example calculating the phasing degree from the measurement loop is 30 °, and the phasing degree that real protection CT loop records is 35 °, is 5 ° after subtract each other at two phasing degree so, and we think that the angle after subtracting each other at ± 30 ° all is and this equal angular.Also having a kind of situation to consider, is exactly that this needs the staff to be noted because measurement CT loop is opposite with the extension line polarity in protection CT loop, and two phasing degree will differ 180 ° so;
5) judged result of the single protection of output CT circuit connection correctness;
6) carry out the judgement of the CT circuit connection correctness of each side of main transformer according to the method described above successively;
7) after the judgement of the CT circuit connection correctness of finishing each side, adopt the simultaneously-measured method of each side homophase to judge the correctness of each side CT composite vector of conventional transformer differential protection.
8) the facies analysis result is closed in output.
Above-mentioned relay protection of power system CT circuit connection analytical approach also comprised before step 7):
1) obtain conventional transformer differential protecting CT loop measured value and parameter:
Conventional transformer differential protecting CT loop measured value and parameter comprise: the mode of connection of the current effective value of each winding and phase place, conventional transformer, each winding CT no-load voltage ratio, each winding rated voltage, each winding be meritorious, idle to be sent and is subjected to electric situation, main electrical scheme situation, whether passes through secondary connection adjustment and the corresponding switch number of each winding;
2) according to the conventional transformer parameter conventional transformer differential protecting CT loop measured value is converted, its specific implementation is:
2.1) calculate the coefficient of balance of each winding of conventional transformer;
2.2) according to the convert current effective value of this winding of the coefficient of balance of each winding of conventional transformer;
2.3) all current phases are deducted with the measurement loop is the phase power angle of reference;
2.4) judge whether reference voltage is Ua, if then direct execution in step 2.5); If not then reference voltage being converted to behind the Ua execution in step 2.5 again);
2.5) if conventional transformer differential protecting CT loop is analyzed; then to carry out causing the compensation of each side primary current phase difference, preserve parameter and execution in step 7 after converting then) owing to the difference of a winding connection mode of each side of conventional transformer.Whether the CT extension line of each side of conventional transformer is unified to draw for positive polarity, or unified draws for negative polarity, otherwise can cause 8) mistake of step analysis, judged result.
Wherein the computing method of coefficient of balance are: the secondary rated current of calculating each winding; Formula one:
Have according to formula one:
Wherein, S is the capacity of conventional transformer; U is a winding primary side rated line voltage; I is a winding primary side rated current; Ie is a winding secondary rated current; Nct is a winding CT no-load voltage ratio.
Calculate the secondary rated current of each winding according to above-mentioned formula two.
If one coefficient of balance of a rated current maximum of each winding is 1, convert the coefficient of balance of other windings; Coefficient of balance should be smaller or equal to 4, if having in each lateral balance coefficient greater than 4, so it are made as 4, the coefficient of balance of other windings changed again.
Because the singularity of conventional transformer differential circuit; also to carry out the judgement of the whole wiring correctness of conventional transformer differential protection; at this moment main what judge is whether each side of conventional transformer is unified to draw for positive polarity or negative polarity, and whether the no-load voltage ratio of CT is carried out according to no-load voltage ratio given in the definite value.
Wiring state according to output is corrected error situation.The wiring state of its each phase has respectively for certain winding or linkage unit: A has mutually: the A phase connection is correct, A joins instead with B, A joins instead with C, A phase polarity connects instead, A joins with B, and anti-and current B phase polarity connects instead, A joins anti-with C and current C phase polarity connects instead; B has mutually: the B phase connection is correct, B joins instead with A, B joins instead with C, B joins with A, and anti-and current A phase polarity connects instead, B phase polarity connects instead, B joins anti-with C and current C phase polarity connects instead; C has mutually: the C phase connection is correct, C joins instead with A, C joins instead with B, C joins with A, and anti-and current A phase polarity connects instead, C joins with B, and anti-and current B phase polarity connects instead, C phase polarity connects instead.
Adopt the simultaneously-measured method of each side homophase to close phase, the reference vector of closing phase is that the side with the load current maximum that records in each side of conventional transformer is a benchmark, and the vector of other each side compares with it after closing mutually.The analysis result that generates is: wiring is correct, wiring error.
Claims (4)
1. the many lists of winding conventional transformer close differential protecting CT wiring correctness analytical approachs, and its special character is: this method may further comprise the steps:
1) according to obtaining correct instantaneous meritorious, idle in this loop and send, be subjected to situation from measuring methods such as loop or the calculating of bus electric quantity balancing;
2) according to the situation that is subjected to of sending of instantaneous meritorious, capacity of idle power, all is to be that reference voltage calculates correct phasing degree automatically with Ua generally;
3) draw correct vector relations according to the correct phasing degree that calculates;
4) phasing degree of this loop protection of actual measurement CT loop A, B, C phase, there is error at the phasing degree of actual measurement with the phasing degree that calculates according to the measurement loop, the phasing degree of protection CT loop A, B, C phase will deduct according to measuring the phasing degree that the loop calculates, and judges the correctness of this protection CT circuit connection;
5) judged result of the single protection of output CT circuit connection correctness;
6) carry out the judgement of the CT circuit connection correctness of each side of main transformer according to the method described above successively;
7) after the judgement of the CT circuit connection correctness of finishing each side, adopt the simultaneously-measured method of each side homophase to judge the correctness of each side CT composite vector of conventional transformer differential protection.
8) the facies analysis result is closed in output.
2. according to the many single differential protecting CT wiring correctness analytical approachs of closing of the described two winding conventional transformers of claim 1, it is characterized in that: described relay protection of power system CT circuit connection analytical approach also comprised before step 7):
1) obtain conventional transformer differential protecting CT loop measured value and parameter:
Conventional transformer differential protecting CT loop measured value and parameter comprise: the mode of connection of the current effective value of each winding and phase place, conventional transformer, each winding CT no-load voltage ratio, each winding rated voltage, each winding be meritorious, idle to be sent and is subjected to electric situation, main electrical scheme situation, whether passes through secondary connection adjustment and the corresponding switch number of each winding;
2) according to the conventional transformer parameter conventional transformer differential protecting CT loop measured value is converted, its specific implementation is: the coefficient of balance that calculates each winding of conventional transformer; According to the convert current effective value of this winding of the coefficient of balance of each winding of conventional transformer; It is the phase power angle of reference that all current phases are deducted with the measurement loop; Judge whether reference voltage is Ua; After then reference voltage being converted to Ua; If conventional transformer differential protecting CT loop is analyzed, then to carry out causing the compensation of each side primary current phase difference owing to the difference of a winding connection mode of each side of conventional transformer, preserve parameter and execution in step 7 after converting then).
3. according to the many single differential protecting CT wiring correctness analytical approachs of closing of the described two winding conventional transformers of claim 2; it is characterized in that: described step 6) adopts the simultaneously-measured method of each side homophase to close phase; the reference vector of closing phase is that the side with the load current maximum that records in each side of conventional transformer is a benchmark, and the vector of other each side compares with it after closing mutually.
4. according to the many single differential protecting CT wiring correctness analytical approachs of closing of the described two winding conventional transformers of claim 3, it is characterized in that: the analysis result that generates in the described step 7) is: wiring is correct, wiring error.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009103114925A CN102095958A (en) | 2009-12-15 | 2009-12-15 | Method for analyzing wiring correctness of double-winding conventional transformer single-switch differential protection CT |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009103114925A CN102095958A (en) | 2009-12-15 | 2009-12-15 | Method for analyzing wiring correctness of double-winding conventional transformer single-switch differential protection CT |
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| CN102095958A true CN102095958A (en) | 2011-06-15 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2009103114925A Withdrawn CN102095958A (en) | 2009-12-15 | 2009-12-15 | Method for analyzing wiring correctness of double-winding conventional transformer single-switch differential protection CT |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102636726A (en) * | 2012-04-16 | 2012-08-15 | 许继集团有限公司 | Method for carrying out adaptive discriminating on polarity of CT (current transformer) of new line in distribution network |
| CN103245842A (en) * | 2013-04-18 | 2013-08-14 | 国家电网公司 | Detection method for full-system simulation running of 10-35 kV newly-mounted electrical device |
| CN103500990A (en) * | 2013-09-30 | 2014-01-08 | 国家电网公司 | Selection method of buscouple CT (current transformer) winding in optimized busbar differential protection devices |
| CN104459435A (en) * | 2014-11-21 | 2015-03-25 | 国家电网公司 | Wiring verification method and device for transformer substation |
| CN104730408A (en) * | 2015-03-03 | 2015-06-24 | 国家电网公司 | Method for verifying correctness of differential circuit of transformer with large capacity |
| CN113325337A (en) * | 2021-04-14 | 2021-08-31 | 深圳市盛弘电气股份有限公司 | Source-side current transformer wiring detection method and system and current management equipment |
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2009
- 2009-12-15 CN CN2009103114925A patent/CN102095958A/en not_active Withdrawn
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102636726A (en) * | 2012-04-16 | 2012-08-15 | 许继集团有限公司 | Method for carrying out adaptive discriminating on polarity of CT (current transformer) of new line in distribution network |
| CN103245842A (en) * | 2013-04-18 | 2013-08-14 | 国家电网公司 | Detection method for full-system simulation running of 10-35 kV newly-mounted electrical device |
| CN103245842B (en) * | 2013-04-18 | 2015-10-07 | 国家电网公司 | 10 ~ 35kV new clothes electric device total system dry run detection method |
| CN103500990A (en) * | 2013-09-30 | 2014-01-08 | 国家电网公司 | Selection method of buscouple CT (current transformer) winding in optimized busbar differential protection devices |
| CN103500990B (en) * | 2013-09-30 | 2016-02-10 | 国家电网公司 | A kind of system of selection optimizing mother CT winding in bus differential protection device |
| CN104459435A (en) * | 2014-11-21 | 2015-03-25 | 国家电网公司 | Wiring verification method and device for transformer substation |
| CN104459435B (en) * | 2014-11-21 | 2017-06-16 | 国家电网公司 | A kind of wiring verification method and device for transformer station |
| CN104730408A (en) * | 2015-03-03 | 2015-06-24 | 国家电网公司 | Method for verifying correctness of differential circuit of transformer with large capacity |
| CN104730408B (en) * | 2015-03-03 | 2017-11-14 | 国家电网公司 | A kind of method for verifying high-power transformer differential circuit correctness |
| CN113325337A (en) * | 2021-04-14 | 2021-08-31 | 深圳市盛弘电气股份有限公司 | Source-side current transformer wiring detection method and system and current management equipment |
| CN113325337B (en) * | 2021-04-14 | 2022-12-27 | 深圳市盛弘电气股份有限公司 | Source-side current transformer wiring detection method and system and current management equipment |
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Open date: 20110615 |