CN111987688A - Method for restraining error action of restorable disturbance differential protection - Google Patents
Method for restraining error action of restorable disturbance differential protection Download PDFInfo
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- CN111987688A CN111987688A CN202010751382.7A CN202010751382A CN111987688A CN 111987688 A CN111987688 A CN 111987688A CN 202010751382 A CN202010751382 A CN 202010751382A CN 111987688 A CN111987688 A CN 111987688A
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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
- H02H3/02—Details
- H02H3/05—Details with means for increasing reliability, e.g. redundancy arrangements
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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
- H02H3/02—Details
- H02H3/027—Details with automatic disconnection after a predetermined time
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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
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Abstract
The invention relates to a method for restraining error action of restitution disturbance differential protection, which is mainly applied to a high-voltage relay protection device adopting a current differential principle. For recovery disturbance, locking differential protection is directly implemented, and for conversion fault differential current, action is implemented after time delay, so that the reliability of differential protection is improved.
Description
Technical Field
The invention relates to the technical field of power system relay protection, in particular to a method for suppressing the misoperation of restorative disturbance differential protection.
Background
The differential protection is used as the main protection of primary main equipment of the power system, has the advantages of simple principle, high action speed and the like, and plays an important role in the safe operation of the power system.
In recent years, with the construction and application of high-voltage long-distance transmission projects, the capacity of a power grid is continuously increased, and in order to reduce the influence of CT saturation on differential protection, electronic transformers are generally adopted in transformer substation systems with voltage levels of over 220 kV. However, due to the influence of internal electronic components, the transient characteristic of the electronic transformer is poor during secondary transmission, and a CT trailing phenomenon easily exists during removal of an out-of-range fault. In addition, for differential protection across intervals or voltage levels, a phenomenon that an electronic transformer and a conventional transformer are mixed sometimes exists, and transient characteristics of each CT of the differential protection are inconsistent. All of the above conditions may cause unbalanced currents of different degrees in the differential circuit, which may cause malfunction of the differential protection.
Therefore, in consideration of the influence of CT trailing or CT transient characteristics when the fault of the power system is recovered in different application scenarios of the differential protection, the invention provides a method for suppressing the false action of the restorable disturbance differential protection, and the reliability of the differential protection action is improved.
Disclosure of Invention
Based on the above problems in the prior art, an object of the present invention is to provide a method for suppressing a differential protection malfunction with a restorable disturbance, so as to avoid the differential protection malfunction caused by CT trailing or CT transient characteristics when a power system fault is restored.
In order to achieve the above object, the present invention provides a method for suppressing a recovery disturbance differential protection malfunction, comprising the following steps:
(1) collecting three-phase differential current and braking current of differential protection;
(2) judging whether a certain phase difference current meets the starting condition or not, wherein the time is more than a preset time fixed value, and if the certain phase difference current meets the condition, executing the step (3); if the condition is not met, the step (2) is repeatedly executed;
(3) judging whether the ratio of the phase braking current to the 2T front braking current is smaller than a preset coefficient fixed value or not, and if so, executing the step (4); if the condition is not met, executing the step (5);
(4) identifying the disturbance as recovery disturbance, and locking differential protection;
(5) and (4) differential protection action.
Further, when the determination condition of the step (3) is satisfied, the steps of:
and (3.1) carrying out 1-point differential processing operation on the phase difference current sampling points.
Further, after the step (3.1), performing the steps of:
and (3.2) judging whether the phase 1 point differential current meets a preset differential constant value, if so, executing the step (4), and if not, executing the step (5).
Further, in the step (5), the differential protection operates after a predetermined delay time elapses.
Further, in the step (3.1), the performing 1-point difference processing operation on the phase difference current sampling point specifically includes:
wherein, the formula (1) represents the real part coefficient of the 1-point difference algorithm,
equation (2) represents the imaginary part coefficient of the 1-point difference algorithm,
Nrepresenting the total number of differential stream samples per sample period, N ═ 5.5, -4.5, -3.5, -2.5, …, (N-6.5).
Further, the preset time setting value in the step (2) is in a range of (30,100) ms.
Further, the preset coefficient set value range in the step (3) is (0.5, 1).
Further, In the step (3.2), the preset differential constant value is min {0.04In, 0.8Iset }, where In is a differential protection reference side CT quadratic rating, and Iset is a differential constant value.
According to another aspect of the present invention, the present invention provides a device for implementing a method for suppressing a recovery disturbance differential protection unwanted operation, the device includes a differential protection action logic determination module, a 1-point differential current determination module, a differential protection startup determination module, and a brake current ratio determination module.
Further, the output of the differential protection action logic judgment module is connected with a 40ms delay module; the output of the differential protection starting judgment module and the output of the braking current ratio judgment module are connected with two input ends of a logic 1; the 40ms delay module, the 1-point differential current judgment module and the output of the AND logic 1 are connected with three input ends of an AND logic 2; the output of the differential protection starting judgment module and the output of the braking current ratio judgment module are connected with two input ends of a logic 3; the output of the AND logic 3 of the 40ms delay module is connected with two input ends of an AND logic 4; the output ends of the AND logic 2 and the AND logic 4 are connected with two input ends of an OR logic, and the output end of the OR logic is connected with a differential protection action module to execute differential protection action.
In summary, the present invention provides a method for suppressing a recoverable disturbance differential protection unwanted operation and a device for implementing the method for suppressing the recoverable disturbance differential protection unwanted operation, which are mainly applied to a high-voltage relay protection device adopting a current differential principle, and identify whether a differential current occurring in the differential protection device is a power system recoverable disturbance or a fault differential current caused by an out-of-range conversion fault by judging a characteristic relationship between a three-phase differential current synthesized by a protection device and a brake current. For recovery disturbance, locking differential protection is directly implemented, and for conversion fault differential current, action is implemented after time delay, so that the reliability of differential protection is improved.
The technical scheme of the invention has the following beneficial technical effects: under different scenes applied by differential protection, considering the problems of CT trailing phenomenon caused by the influence of internal electronic elements, inconsistent CT transient characteristics caused by mutual inductors and the like, the adoption of the method for inhibiting the error action of the restorable disturbance differential protection can accurately judge the fault differential current caused by the restorable disturbance of the power system and the out-of-area conversion fault, thereby improving the reliability of the differential protection.
Drawings
FIG. 1 is a flow chart of a method of suppressing a restorative perturbed differential protection glitch;
FIG. 2 is a logic diagram of the differential protection operation.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings in conjunction with the following detailed description. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.
The invention provides a method for suppressing the false action of restorable disturbance differential protection, which is mainly applied to a high-voltage relay protection device adopting the current differential principle and judges the characteristic relation between three-phase differential current and braking current synthesized by the protection device. The method for restraining the error action of the restorable disturbance differential protection is taken as an independent functional module and integrated in a high-voltage current differential protection principle type protection device, and the functional module is always in an input state.
The technical scheme of the invention is explained in detail below, and the invention provides a method for suppressing the false action of the restorable disturbance differential protection, which comprises the following steps:
and (1) acquiring three-phase differential current and braking current of differential protection. According to some embodiments, A, B, C three-phase differential currents and brake currents of differential protection are collected through a current differential protection device, and full-cycle Fourier operation is carried out to calculate effective values of the three-phase differential currents and the brake currents.
Step (2), judging whether a phase difference current meets a starting condition or not, wherein the time is more than a preset time fixed value, and if so, executing the step (3); if the condition is not satisfied, the step (2) is repeatedly executed. The following further describes the execution steps of the method by taking phase a as an example, and the specific execution modes of phase B and phase C are consistent with phase a, and are not described again. And in the functional module of the differential protection device, when the A-phase current full-cycle Fourier effective value is judged to be larger than a preset time fixed value, a time counter is triggered to start accumulating time t. And if the time t is more than 40ms, judging the next step, and if not, continuing to accumulate the waiting time. According to some embodiments, the predetermined time constant is (30,100) ms
Step (3), judging whether the ratio of the phase braking current to the 2T front braking current is smaller than a preset coefficient fixed value, and if the ratio meets the condition, executing step (4); and (5) if the condition is not met, executing the step. According to some embodiments, the value range of the preset coefficient setting value is (0.5,1), and the preset coefficient setting value is set to 0.6 for further explanation, in the step (2), if the time T is greater than 40ms, comparing whether a ratio k of the effective value of the phase a brake current at the current moment to the effective value of the phase a brake current before 2T is less than 0.6, and if the ratio k is greater than or equal to 0.6, jumping to the step (5); and if the ratio k is less than 0.6, judging the next step.
And (3.1) carrying out 1-point differential processing operation on the phase difference current sampling points. According to some embodiments, when the ratio k is less than 0.6, a 1-point difference processing operation is performed on the a-phase differential current sample values, and real and imaginary coefficients after the 1-point difference processing operation are as shown in the following formulas (1) and (2):
wherein, the formula (1) represents the real part coefficient of the 1-point difference algorithm,
equation (2) represents the imaginary part coefficient of the 1-point difference algorithm,
Nrepresenting the total number of differential stream samples per sample period, N ═ 5.5, -4.5, -3.5, -2.5, … …, (N-6.5). According to some embodiments, the sampling rate may be 1200 points per second, at 50Hz power frequency, then: n is 24, N is-5.5, -4.5, -3.5, -2.5, … …, 16.5, 17.5, then N and N are substituted into equations (1) and (2), and a full-cycle fourier operation is performed, thereby calculating the 1-point difference effective value of the a-phase differential current.
And (3.2) judging whether the phase 1 point differential current meets a preset differential constant value, if so, executing the step (4), and if not, executing the step (5). According to some embodiments, the predetermined differential constant is min {0.04In, 0.8Iset }, where In is a CT quadratic rating of the differential protection reference side and Iset is the differential constant.
And (4) identifying the disturbance as recovery disturbance, and locking differential protection.
And (5) performing differential protection action. According to some embodiments, the differential protection is activated after a predetermined delay time, which may be set to 40 ms.
The invention provides a device for realizing a method for restraining the error action of the restorable disturbance differential protection, which comprises a differential protection action logic judgment module, a 1-point differential current judgment module, a differential protection starting judgment module and a brake current ratio judgment module, wherein the differential protection action logic judgment module is used for judging whether the differential protection action logic is met; the 1-point differential current judgment module is used for judging whether the 1-point differential current of a certain phase meets a preset differential constant value; the differential protection starting judgment module is used for judging whether a certain phase difference current meets a starting condition or not, wherein the time is more than a preset time fixed value; the braking current ratio judging module is used for judging whether the ratio of the braking current of a certain phase to the braking current before 2T is smaller than a preset coefficient fixed value or not.
The connection mode of each judgment module meeting the condition output is as follows: the output of the differential protection action logic judgment module is connected with a 40ms delay module; the output of the differential protection starting judgment module and the output of the braking current ratio judgment module are connected with two input ends of a logic 1; the 40ms delay module, the 1-point differential current judgment module and the output of the AND logic 1 are connected with three input ends of an AND logic 2; the output of the differential protection starting judgment module and the output of the braking current ratio judgment module are connected with two input ends of a logic 3; the output of the AND logic 3 of the 40ms delay module is connected with two input ends of an AND logic 4; the output ends of the AND logic 2 and the AND logic 4 are connected with two input ends of an OR logic, and the output end of the OR logic is connected with a differential protection action module to execute differential protection action.
In summary, the present invention relates to a method for suppressing a recoverable disturbing differential protection glitch, and an apparatus for performing the same. The method is mainly applied to a high-voltage relay protection device adopting a current differential principle, and the differential current in the differential protection device is identified to be the power system recovery disturbance or the fault differential current caused by the distinguished conversion fault by judging the characteristic relation between the three-phase differential current and the braking current synthesized by the protection device. For recovery disturbance, locking differential protection is directly implemented, and for conversion fault differential current, action is implemented after time delay, so that the reliability of differential protection is improved. By the suppression method and the suppression device, under different scenes in which differential protection is applied, the problems of CT trailing phenomenon caused by the influence of internal electronic elements, inconsistent CT transient characteristics caused by mutual inductor mixing and the like are considered, and by the adoption of the suppression method for the recovery disturbance differential protection misoperation, the fault differential current caused by the recovery disturbance and the out-of-range conversion fault of the power system can be accurately judged, so that the reliability of the differential protection is improved.
It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explaining the principles of the invention and are not to be construed as limiting the invention. Therefore, any modification, equivalent replacement, improvement and the like made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. Further, it is intended that the appended claims cover all such variations and modifications as fall within the scope and boundaries of the appended claims or the equivalents of such scope and boundaries.
Claims (10)
1. A method for suppressing a recovery disturbance differential protection malfunction, comprising the steps of:
(1) collecting three-phase differential current and braking current of differential protection;
(2) judging whether a certain phase difference current meets the starting condition or not, wherein the time is more than a preset time fixed value, and if the certain phase difference current meets the condition, executing the step (3); if the condition is not met, the step (2) is repeatedly executed;
(3) judging whether the ratio of the phase braking current to the 2T front braking current is smaller than a preset coefficient fixed value or not, and if so, executing the step (4); if the condition is not met, executing the step (5);
(4) identifying the disturbance as recovery disturbance, and locking differential protection;
(5) and (4) differential protection action.
2. The suppressing method according to claim 1, wherein when the determination condition of the step (3) is satisfied, the step of:
and (3.1) carrying out 1-point differential processing operation on the phase difference current sampling points.
3. The suppression method according to claim 2, characterized in that after said step (3.1), the step of:
and (3.2) judging whether the phase 1 point differential current meets a preset differential constant value, if so, executing the step (4), and if not, executing the step (5).
4. The suppressing method according to claim 1, wherein in the step (5), the differential protection is activated after a predetermined delay time.
5. The suppressing method according to claim 2, wherein in the step (3.1), the 1-point difference processing operation performed on the phase-difference current sampling points is specifically:
wherein, the formula (1) represents the real part coefficient of the 1-point difference algorithm,
equation (2) represents the imaginary part coefficient of the 1-point difference algorithm,
n represents the total number of differential stream samples per sample period, N being-5.5, -4.5, -3.5, -2.5, …, (N-6.5).
6. The suppressing method according to claim 1, wherein the range of the preset time setting value in the step (2) is (30,100) ms.
7. The suppressing method according to claim 1, wherein the preset coefficient set value range in the step (3) is (0.5, 1).
8. The suppressing method according to claim 3, wherein In the step (3.2), the preset differential setting value is min {0.04In, 0.8Iset }, where In is a differential protection reference side CT quadratic rating and Iset is a differential setting value.
9. The device is characterized by comprising a differential protection action logic judgment module, a 1-point differential current judgment module, a differential protection starting judgment module and a brake current ratio judgment module.
10. The apparatus of claim 9, wherein the output of the differential protection action logic determining module is connected to a 40ms delay module; the output of the differential protection starting judgment module and the output of the braking current ratio judgment module are connected with two input ends of a logic 1; the 40ms delay module, the 1-point differential current judgment module and the output of the AND logic 1 are connected with three input ends of an AND logic 2; the output of the differential protection starting judgment module and the output of the braking current ratio judgment module are connected with two input ends of a logic 3; the output of the AND logic 3 of the 40ms delay module is connected with two input ends of an AND logic 4; the output ends of the AND logic 2 and the AND logic 4 are connected with two input ends of an OR logic, and the output end of the OR logic is connected with a differential protection action module to execute differential protection action.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102082422A (en) * | 2010-12-15 | 2011-06-01 | 国网电力科学研究院 | Method for preventing fault actions of line longitudinal differential protection caused by non-fault phase secondary current abrupt change |
| CN102611086A (en) * | 2012-03-27 | 2012-07-25 | 许继集团有限公司 | Centralized protection system and method for region distribution network |
| CN104682360A (en) * | 2015-01-22 | 2015-06-03 | 南京南瑞继保电气有限公司 | Method and device for identifying current transformer (TA) saturation |
| CN105024365A (en) * | 2015-08-05 | 2015-11-04 | 许继集团有限公司 | Sampling point differential protection misoperation prevention method |
| CN105703332A (en) * | 2016-03-11 | 2016-06-22 | 河南许继智能科技股份有限公司 | Anti-TA saturation differential protection method and device for transformer |
| US20170018919A1 (en) * | 2015-07-17 | 2017-01-19 | Xj Group Corproation | Prevention method of abnormal action protection of uhv regulating compensation transformer with no-load input |
| CN109672154A (en) * | 2019-01-08 | 2019-04-23 | 许昌许继软件技术有限公司 | A kind of method and device for preventing non-faulting to be mutually saturated differential protection malfunction |
-
2020
- 2020-07-30 CN CN202010751382.7A patent/CN111987688B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102082422A (en) * | 2010-12-15 | 2011-06-01 | 国网电力科学研究院 | Method for preventing fault actions of line longitudinal differential protection caused by non-fault phase secondary current abrupt change |
| CN102611086A (en) * | 2012-03-27 | 2012-07-25 | 许继集团有限公司 | Centralized protection system and method for region distribution network |
| CN104682360A (en) * | 2015-01-22 | 2015-06-03 | 南京南瑞继保电气有限公司 | Method and device for identifying current transformer (TA) saturation |
| US20170018919A1 (en) * | 2015-07-17 | 2017-01-19 | Xj Group Corproation | Prevention method of abnormal action protection of uhv regulating compensation transformer with no-load input |
| CN105024365A (en) * | 2015-08-05 | 2015-11-04 | 许继集团有限公司 | Sampling point differential protection misoperation prevention method |
| CN105703332A (en) * | 2016-03-11 | 2016-06-22 | 河南许继智能科技股份有限公司 | Anti-TA saturation differential protection method and device for transformer |
| CN109672154A (en) * | 2019-01-08 | 2019-04-23 | 许昌许继软件技术有限公司 | A kind of method and device for preventing non-faulting to be mutually saturated differential protection malfunction |
Non-Patent Citations (1)
| Title |
|---|
| 戚宣威 等: "区外故障导致变压器电流互感器饱和及差动保护误动问题研究", 《电力***保护与控制》 * |
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