CN117518057A - Differential cooperation checking method and differential cooperation checking instrument for transformer substation direct current system protector - Google Patents
Differential cooperation checking method and differential cooperation checking instrument for transformer substation direct current system protector Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
- G01R35/005—Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/20—Modifications of basic electric elements for use in electric measuring instruments; Structural combinations of such elements with such instruments
- G01R1/203—Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
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Abstract
本发明公开一种变电站直流系统保护器级差配合校验方法及级差配合检验仪器，属于保护器配合校验技术领域。通过由可调直流逆变输出模块、启动控制模块、测试主回路和分析计算校核模块构成的级差配合检验设备，通过构建直流系统保护器拓扑结构，获得直流系统内被测保护器的安秒特性，建立级差配合仿真模型，利用拟合算法计算安秒特性函数，进行级差配合仿真检验，并连接到实际直流系统，对保护器的级差配合进行实际验证，解决可覆盖宽范围的短路电流响应特性问题，适用于任何电流下的保护器的匹配检验。本发明既可解决快速判断保护器上下级差配合情况，又能解决配合关系的实际验证，保证直流系统稳定可靠安全供应，确保变电站安全稳定运行。
The invention discloses a differential coordination verification method and a differential coordination inspection instrument for a protector in a substation DC system, and belongs to the technical field of protector coordination verification. Through the step-by-step coordination inspection equipment composed of an adjustable DC inverter output module, a start-up control module, a test main circuit and an analysis and calculation verification module, and by constructing a DC system protector topology, the ampere seconds of the tested protector in the DC system is obtained. Characteristics, establish a step cooperation simulation model, use the fitting algorithm to calculate the ampere-second characteristic function, conduct step cooperation simulation verification, and connect it to the actual DC system to conduct actual verification of the step cooperation of the protector and solve the short-circuit current response that can cover a wide range Characteristic issues, suitable for matching inspection of protectors under any current. The invention can not only quickly determine the differential coordination between the upper and lower stages of the protector, but also solve the actual verification of the coordination relationship, ensure a stable, reliable and safe supply of the DC system, and ensure the safe and stable operation of the substation.
Description
Technical Field
The invention relates to the technical field of protector cooperation verification, in particular to a level difference cooperation verification technology of a direct current system protector.
Background
The direct current system is an important component of the transformer substation, is a power supply of relay protection, measurement and control automation equipment, a control system and a signal system, and can ensure the correct action of the relay protection device only through stable, reliable and safe supply of the direct current system, and ensure the safe and stable operation of the transformer substation only through correct execution of remote control, remote signaling and remote measurement.
The direct current system starts from the rectifying module or the storage battery, passes through the protectors at all levels and reaches the load equipment, the serial number of the protectors of the whole loop reaches three to four levels, and the multistage serial connection brings great difficulty to the selective matching of the protectors. In recent years, a multi-cause protector level difference mismatching occurs in a transformer substation, so that an override trip accident occurs. In order to reduce the occurrence of error event of the level difference matching of the protector, the level difference matching check of the direct current system protector before the operation of the transformer substation is required to be enhanced, and the problem of improper matching is found in advance.
At present, a conventional direct current protector characteristic checking instrument or method can only measure the action characteristic of a single protector, and judges whether the protector meets the design requirement according to the action condition and time of the protector by inputting short-circuit currents with different magnitudes for multiple times. The method can not directly judge whether the matching relationship between the upper and lower stages of the protector is correct, and manual judgment is needed to be additionally carried out according to the respective characteristics, so that the level difference verification work efficiency of the protector is low. As disclosed in chinese patent document CN102284764B, the "method for testing level difference matching of a power dc system protection device based on a wave recording manner" judges whether each dc protector is good or not through an on-site short-circuit fault test, but the scheme can only test the response characteristics of short-circuit current within a certain range within a specific current range, and cannot quickly verify the upper and lower level matching condition and actual verification of the protector.
Disclosure of Invention
In view of the fact that the prior art can only test short-circuit current response characteristics within a certain range, it is difficult to cover short-circuit current response characteristics within a wide range, and in actual operation of a direct current system, the short-circuit current is wide in size range due to various short-circuit types, and the testing method in the prior art cannot verify the matching condition of protectors under various short-circuit currents. Therefore, a brand new calibration method for the direct current system protector of the transformer substation is urgently needed, the upper and lower level matching conditions of the protector can be judged rapidly, and the matching relation and actual verification under various short-circuit fault conditions can be simulated and tested. The invention aims to solve the technical problems of effectively and rapidly judging the upper and lower level difference matching condition of the protector, checking the level difference matching relation of the protector of the whole direct current system and practical verification.
The invention aims to provide a level difference matching verification method for a direct current system protector of a transformer substation, which is used for constructing a topological structure of the direct current system protector in the transformer substation and verifying the level difference matching relation of the whole direct current system protector by simulating various short circuit faults, and comprises the following steps: step one: constructing a topological structure of a protector of a direct current system in a transformer substation, connecting a level difference cooperation checking instrument, and testing the ampere-second characteristics of each protector to be tested in the direct current system; step two: establishing a level difference matching simulation model according to the direct current system structure, calculating an ampere-second characteristic function of the protector by using a fitting algorithm, and performing level difference matching simulation test; step three: and connecting the level difference matching checking instrument to an actual direct current system, and performing actual checking on the level difference matching of the plurality of protectors.
The scheme adopts the ampere-second characteristic function, solves the problem of wide current range, can cover the short-circuit current response characteristic of wide range, can be suitable for the matching test of the protector under any current, can obtain the actual ampere-second characteristic function through a fitting algorithm, and solves the matching relation under any fault current. The invention can not only solve the problem of rapid judgment of the upper and lower level difference matching condition of the protector, but also solve the actual verification of the matching relation, ensure the stable, reliable and safe supply of the direct current system and ensure the safe and stable operation of the transformer substation. The ampere-second characteristic is a characteristic relationship between an operation current and an operation time. The protector ampere-second characteristic is a main index for measuring the performance of the protector.
In the scheme, in the first step, a tested protector and a level difference matching checking instrument are connected, an inverter power switch, the tested protector and a starting power switch are sequentially closed, then an output current value of the inverter is set, and a test button is pressed; when the test is carried out, the current/time collector records the current value and the action time when the tested protector is tripped; and regulating different output current values of the inverter, performing multiple tests, and recording the action current value and time of the tested protector during each test.
In the scheme, in the second step, through simulating input fault current, based on ampere-second characteristic functions of each protector, the action time of each protector is calculated, action delay set by each protector is fitted, the action time of the fitted protectors is compared by a tripping time sequence comparator, and whether the level difference matching of the direct current system is correct or not is judged: when the equipment fails, the action time of each protector is calculated and sequenced, and when the protectors are distributed sequentially, the protector level difference matching is judged to be correct, otherwise, the protector level difference matching is judged to be incorrect.
And further, capturing and collecting the protector action current value and action time, and solving the protector ampere-second characteristic function by using a fitting algorithm. The function fit is:
wherein: A. b, C, D, E, G, H are fitting parameters; t is action time; t is t 0 And t 1 The lower limit and the upper limit of the straight line characteristic part of the ampere second characteristic curve are respectively set; t is t 2 And t 3 The lower limit and the upper limit of the index characteristic part of the ampere-second characteristic curve are respectively set; e is a natural constant.
And further, according to the direct current system structure, establishing a level difference cooperation simulation model, and solving the cooperation relation under any fault current by utilizing an ampere-second characteristic function.
In the scheme, in the third step, a plurality of protectors are sequentially closed, a power switch is started, and then a test button is pressed to start a test for verification: when the protector is in a tripping action and other protectors are not moving, judging that the level difference matching is correct, otherwise judging that the level difference matching is wrong; meanwhile, a current/time collector is adopted to check the action current and time of other protectors, and review and prove.
And further, when the actual verification is carried out, the actual operation storage battery pack is used as an action power supply, the action characteristics of the protector are verified, and meanwhile, whether the superior protector is mismatched or not is tested.
The invention also provides the scheme that: the level difference matching checking instrument is applied to a level difference matching checking method of a direct current system protector of a transformer substation, and comprises a checking system mainly composed of four functional modules: the adjustable direct current inversion output module comprises: the inverter converts standard alternating current into direct current, and can adjust the output value to provide power for testing the ampere-second characteristic of the protector; and a starting control module: the test device consists of a test button and a starting relay, and is used for controlling the on-off of a test main loop; testing the main loop: the protector consists of a starting contact, an ammeter and a current/time collector, and is used for testing the action current and action time of the protector; and an analysis and calculation checking module: and fitting and calculating an ampere-second characteristic function of the protector, performing analog simulation calculation check on level difference matching, and performing data exchange with a current/time collector in the test main loop.
In the scheme, the time relay is used for controlling the timing on-off of the test main loop, and when the time delay is exceeded and the test main loop does not still move to trip, the test main loop is automatically disconnected, so that the test safety is improved.
The level difference cooperation checking equipment is composed of an adjustable direct current inversion output module, a starting control module, a testing main loop and an analysis calculation checking module serving as main components, and is applied to a level difference cooperation checking method of a direct current system protector of a transformer substation, so that an ampere-second characteristic function is obtained, the characteristic characterization problem of a short circuit current response in a wide range of current is solved, the method is suitable for matching checking of the protector under any current, an actual ampere-second characteristic function can be obtained through a fitting algorithm, and the cooperation relation under any fault current is solved, so that the method can solve the problem of quickly judging the upper and lower level difference cooperation condition of the protector, and can solve the actual verification of the cooperation relation, ensure the stable, reliable and safe supply of the direct current system, and ensure the safe and stable operation of the transformer substation.
Compared with the prior art, the invention has the beneficial effects that:
the invention obtains an ampere-second characteristic function through the level difference cooperation checking equipment which is composed of the adjustable direct current inversion output module, the starting control module, the testing main loop and the analysis calculation checking module as main components and is applied to the level difference cooperation checking method of the direct current system protector of the transformer substation, solves the characteristic characterization problem of the short circuit current response characteristic in a wide range of current, and is suitable for the matching checking of the protector under any current.
The invention obtains the ampere-second characteristics of each tested protector in the direct current system by constructing the topological structure of the protector of the direct current system in the transformer substation, establishes a level difference cooperation simulation model, calculates an ampere-second characteristic function by using a fitting algorithm, performs level difference cooperation simulation test, is connected to an actual direct current system, performs actual verification on level difference cooperation of a plurality of protectors, solves the problem of short circuit current response characteristics which can cover a wide range, can be suitable for matching test of protectors under any current, can obtain an actual ampere-second characteristic function by using the fitting algorithm, and solves the cooperation relation under any fault current.
The invention can not only solve the problem of rapid judgment of the upper and lower level difference matching condition of the protector, but also solve the actual verification of the matching relation, ensure the stable, reliable and safe supply of the direct current system and ensure the safe and stable operation of the transformer substation.
Drawings
FIG. 1 is a flow chart of the level difference matching verification method of the present invention.
FIG. 2 is a schematic diagram of a level difference fit inspection system according to the present invention.
FIG. 3 is a flow chart of an embodiment verification.
Fig. 4 is a diagram of a protector ampere-second characteristic test wiring.
FIG. 5 is a schematic diagram of a level difference fit simulation test.
Fig. 6 is a diagram of a step-difference fit actual verification wiring.
Detailed Description
The technical scheme of the invention is further specifically described by the following specific embodiments.
Example 1.
As shown in fig. 2, the present embodiment provides a level difference mating inspection instrument, which includes an inspection system mainly composed of four functional modules: the system comprises an adjustable direct current inversion output module, a starting control module, a test main loop and an analysis, calculation and check module. The adjustable DC inversion output module mainly comprises an inverter, an inverter power switch and an ammeter, and is used for converting alternating current 220V into direct current, and the output size can be adjusted, so that a power supply is provided for testing the ampere-second characteristic of the protector. The starting control module consists of a CK test button and a QD starting relay and is used for controlling the on-off of the test main loop. The test main loop consists of a starting contact, an ammeter and a current/time collector and is used for testing the action current and action time of the protector. The analysis calculation checking module is used for fitting and calculating an ampere-second characteristic function of the tested protector, and the level difference is matched with the simulation calculation check. And the analysis and calculation checking module exchanges data with a current/time collector in the test main loop. The time relay is used for controlling the timing on-off of the test main loop, and when the time delay is exceeded and the test main loop does not move and breaks away, the test main loop is automatically disconnected, so that the test safety is improved.
The level difference matching inspection system provided by the embodiment is used for level difference matching inspection of the protector of the direct current system of the transformer substation, comprises a breaker, an air switch and other protectors, and can be used for inspection of ampere-second characteristics and judgment of arc extinguishing characteristics. With the development of intellectualization and digitalization of a transformer substation, the requirements on the safety and the reliability of a direct current system are gradually increased, if the direct current protection equipment is improperly selected and the level difference is not reasonably matched, the override action can occur under the fault condition, the fault point can not be correctly cut off, and the accident range can be enlarged. The present embodiment is applicable to a solution of this scenario.
Example 2.
As shown in fig. 1, the present embodiment provides a level difference matching verification method for a direct current system protector of a transformer substation, which mainly includes the following steps: step one: constructing a topological structure of a protector of a direct current system in a transformer substation, connecting a level difference cooperation checking instrument, and testing the ampere-second characteristics of each protector to be tested in the direct current system; step two: and establishing a level difference cooperation simulation model according to the direct current system structure, calculating an ampere-second characteristic function of the protector by using a fitting algorithm, solving a cooperation relation under any fault current by using the ampere-second characteristic function, and performing level difference cooperation simulation test. Step three: and connecting the level difference matching checking instrument to an actual direct current system, and performing actual checking on the level difference matching of the plurality of protectors.
The details of the operation steps of this embodiment are described below:
each protector in the dc system was tested for ampere-second characteristics. The protector DK1 is connected with the level difference matching checking instrument in a mode shown in fig. 4, after test wiring is completed, an inverter power switch ZK1, a tested protector DK1 and a starting power switch ZK2 are sequentially closed, then an output current value of the AC/DC inverter is set, and a test button CK is pressed to start testing. The current/time collector will record the current level I and the action time T at which DK1 will trip. And (3) regulating the magnitude of different output current values of the AC/DC inverter, performing multiple tests, recording the DK1 action current and time during each test, and calculating an ampere-second characteristic function of the protector DK1 by using a fitting method.
And performing level difference matching simulation verification according to the direct current system structure. The upper part shown in fig. 5 is a typical three-layer structure direct current system, F is a battery outlet fuse, S2 is a feed on-screen air switch, S3 is a direct current split-screen air switch, and S4, S5, S6 are load on-screen equipment air switches. The left side is fault current, and the right side is the result after the comparison of trip time sequence comparator. According to the direct current system structure, a level difference matching simulation model is established, F (I) fits and calculates the calculated ampere-second characteristic function for each protector, deltat is the action delay set by each protector, and S2, S3, S4 and F action time are calculated by simulating input fault current I and are respectively as follows: and (3) determining whether the level difference matching of the direct current system is correct by comparing the action time of the 4 protectors by T2+Deltat2, T3+Deltat3, T4+Deltat4 and Tf. When the fault occurs at the equipment G1 in the figure, the (T4+deltat4) < (T3+deltat3) < (T2+deltat2) < (Tf) is calculated, and the protector level difference matching is judged to be correct.
And (5) performing verification in an actual direct current system. The step-difference fit checking instrument is connected to an actual direct current system in a manner shown in fig. 6, and actual verification is performed on the step-difference fit of the protector DK1 and the protector DK 2. DK1, DK2 and ZK2 are sequentially closed according to the jump, and then a test button CK is pressed to start the test. If DK2 is disengaged and DK1 is not moved, the level difference matching is judged to be correct, otherwise, the matching is judged to be incorrect. The DK2 action current and time can be checked by the current/time collector.
The embodiment can accurately measure the ampere-second characteristic of the direct current protector, establish an ampere-second characteristic function relation by using a fitting method, and can arbitrarily check the level difference fit condition of the protector under the condition of fault currents of various magnitudes by constructing a check model. By adopting a high-precision level difference matching calibration instrument, the accuracy of short-circuit current wave recording and breaking time measurement is ensured.
Example 3.
As shown in fig. 3, the operation steps for quick verification in this embodiment are as follows:
and an ampere-second characteristic test wiring. The wiring is performed in the manner shown in fig. 4, and the inverter power switch ZK1, the protector to be tested DK1, and the start power switch ZK2 are sequentially turned on to set the output current value of the AC/DC inverter.
An ampere-second characteristic test is initiated. Pressing the test button CK, DK1 is released, and the current/time collector records the current and the action time during the action.
An ampere-second characteristic function is calculated. And (3) performing multiple tests on DK1, recording multiple groups of action currents and action time, and fitting to obtain an Ans characteristic function of DK 1.
And (5) starting the level difference matching simulation verification. According to the direct current system structure shown in fig. 5, a simulation verification model is established in an analysis and calculation verification module, the action time under a certain fault current is calculated according to the ampere-second characteristic function of each protector, and whether the level difference meets the requirement is judged according to the action time.
And (5) verifying in an actual direct current system. Wiring is performed in the manner shown in fig. 6, sequentially closing DK1, DK2, ZK2, and then pressing the test button CK starts the test. If DK2 is disengaged and DK1 is not moved, the level difference matching is judged to be correct, otherwise, the matching is judged to be incorrect. When the actual verification is carried out, the actual operation storage battery pack is used as an action power supply, the action characteristics of the protector are verified, and meanwhile, whether the superior protector has mismatch is tested.
And (5) ending the test. And after the test is finished, removing the wiring and recovering the site. The embodiment can solve the problems that the protector is gradually passivated along with the current increase in the action curve, the quick-break action time cannot be reached later, and the override trip fault occurs at the extreme end or the secondary end of the loop.
The embodiment of the invention can be seen that the invention obtains the ampere-second characteristic of the protector to be tested in the direct current system by constructing the topological structure of the direct current system protector through the level difference cooperation checking equipment consisting of the adjustable direct current inversion output module, the starting control module, the testing main loop and the analysis and calculation checking module, establishes the level difference cooperation simulation model, calculates the ampere-second characteristic function by using a fitting algorithm, carries out level difference cooperation simulation check, is connected to an actual direct current system, carries out actual verification on the level difference cooperation of the protector, solves the problem of short circuit current response characteristic which can cover a wide range, and is suitable for the matching check of the protector under any current. The invention can not only solve the problem of rapid judgment of the upper and lower level difference matching condition of the protector, but also solve the actual verification of the matching relation, ensure the stable, reliable and safe supply of the direct current system and ensure the safe and stable operation of the transformer substation.
Claims (9)
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117805607A (en) * | 2024-02-29 | 2024-04-02 | 山西漳电科学技术研究院(有限公司) | DC level difference matching test method for power plant DC system |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117805607A (en) * | 2024-02-29 | 2024-04-02 | 山西漳电科学技术研究院(有限公司) | DC level difference matching test method for power plant DC system |
| CN117805607B (en) * | 2024-02-29 | 2024-05-07 | 山西漳电科学技术研究院(有限公司) | DC level difference matching test method for power plant DC system |
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