Method for checking differential quick breaking time of differential relay

Abstract

The invention relates to a differential relay differential quick breaking time calibration method. The method comprises the following steps: S1, dismounting a secondary line of a current transformer; s2, wiring; s3, protection switching control word setting; s4, setting over-current protection parameters in a definite time limit; s5, the protection switching state is adjusted; s6, current test and time comparison; s7, repeatedly testing; s8, carrying out large current testing; the comprehensive protection tester is used for channel and time detection, the defect that a large-current generator lacks time detection is overcome, the large-current generator is used for current action testing, the defect that the output current of the comprehensive protection tester is small is overcome, the problem that the output current of the comprehensive protection tester cannot meet the design requirement is solved, and the problem that the output current of the comprehensive protection tester cannot meet the design requirement is solved. And the problem that the large-current generator cannot perform time detection is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer safety testing, and in particular relates to a method for checking the differential current speed breaking time of a differential relay. Background Art

[0002] In the electrical equipment acceptance test, according to the transformer setting value provided by the design institute, the differential current speed cut-off action value is 45.8A on the high-voltage side and 27.9A on the low-voltage side. However, the maximum output current of the comprehensive protection tester is 40A, which cannot meet the verification requirements of the high-voltage side action value. Although the high current generator can produce the required current value, it cannot perform time detection. Therefore, how to use the existing equipment to complete the debugging task has become a challenge for the debugging personnel. Summary of the invention

[0003] The main purpose of the present invention is to propose a method for checking the differential current speed breaking time of a differential relay, which can effectively solve the problems in the background technology.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0005] A differential relay differential flow rate breaking time calibration method comprises the following steps:

[0006] S1: Remove the secondary wires of the current transformer: remove the secondary wires A431, B431, C431, and N431 of the 3LH current transformer on the differential relay;

[0007] S2: Wiring: The current wires of the comprehensive protection tester are connected to the differential relay A, B, C, and N phases according to yellow, green, red, and black respectively;

[0008] S3: Protection on / off control word setting: Enter the protection on / off control word of the differential protection relay through the key and exit all protections;

[0009] S4: Time-limited overcurrent protection parameter setting: adjust the high-voltage side action value from 45.8A to 20A to facilitate testing using a comprehensive protection tester;

[0010] S5: Protection throw-in / out state adjustment: adjust the high-voltage side action value protection throw-in / out control from the out state to the engaged state. This channel is the only engaged channel.

[0011] S6: Current test and time comparison: Use a comprehensive protection tester to pass a 20A current to detect the differential action, and compare the action time detected by the comprehensive protection tester with the action time displayed by the differential relay;

[0012] S7: Repeat the test: Repeat step S6, but adjust the high-voltage side action value to 30A and 40A respectively to confirm the differential action;

[0013] S8: High current test: Use a high current generator to adjust a current of 45.8A, and pass it into phases A, B, and C respectively, confirm that the differential relay operates and the vacuum circuit breaker trips, and confirm the operation time displayed by the differential relay.

[0014] The present invention provides a method for checking the differential current speed breaking time of a differential relay, which has the following beneficial effects:

[0015] The present invention utilizes the comprehensive protection tester to perform channel and time detection, thereby solving the deficiency of a large current generator lacking time detection. The large current generator is utilized to perform current action test, thereby making up for the defect of a small output current of the comprehensive protection tester. This not only solves the problem that the output current of the comprehensive protection tester equipment cannot meet the design requirements, but also solves the problem that the large current generator cannot perform time detection, thereby improving the flexibility and cost-effectiveness of the test, and ensuring the safety and accuracy of the test process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the differential principle diagram of the 35kV transformer of the present invention;

[0017] Figure 2 This is a differential channel detection principle diagram of the present invention;

[0018] Figure 3 It is a differential action confirmation principle diagram of the present invention;

[0019] Figure 4 It is a test report parameter diagram of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention.

[0021] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0023] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Example

[0025] Reference Figure 1-4 , a differential relay differential flow rate breaking time verification method, comprising the following steps:

[0026] S1: Remove the secondary wires of the current transformer: Remove the secondary wires A431, B431, C431, and N431 of the 3LH current transformer on the differential relay to prevent reverse power supply.

[0027] S2: Wiring: The current wires of the comprehensive protection tester are connected to the differential relay A, B, C, and N phases (1ID1, 1ID2, 1ID3, and 1ID4) according to yellow, green, red, and black respectively.

[0028] S3: Protection on / off control word setting: Use the key to enter the protection on / off control word of the differential protection relay, exit all protections, and ensure that the test channel is the only channel.

[0029] S4: Time-limited overcurrent protection parameter setting: adjust the high-voltage side action value from 45.8A to 20A to facilitate testing using a comprehensive protection tester.

[0030] S5: Protection throw-in / out status adjustment: adjust the high-voltage side action value protection throw-in / out control from the exit state to the engaged state. This channel is the only engaged channel.

[0031] S6: Current test and time comparison: Use a comprehensive protection tester to pass a 20A current, detect the differential action, and compare the action time detected by the comprehensive protection tester with the action time displayed by the differential relay.

[0032] S7: Repeat the test: Repeat step 6, but adjust the high-voltage side action value to 30A and 40A respectively to confirm the differential action. If different currents are passed three times to confirm that the differential action is good, it means that the high-voltage side current channel is normal.

[0033] S8: Parameter recovery: restore the high-voltage side action value to 45.8A.

[0034] S8: High current test: Use a high current generator to adjust a current of 45.8A, and pass it into phase A (A431, N431); phase B (B431, N431); phase C (C431, N431), respectively, to confirm that the differential relay operates and the vacuum circuit breaker trips, and record the operation time, and confirm the operation time displayed by the differential relay.

[0035] The present invention utilizes the comprehensive protection tester to perform channel and time detection, thereby solving the deficiency of a large current generator lacking time detection. The large current generator is utilized to perform current action test, thereby making up for the defect of a small output current of the comprehensive protection tester. This not only solves the problem that the output current of the comprehensive protection tester equipment cannot meet the design requirements, but also solves the problem that the large current generator cannot perform time detection, thereby improving the flexibility and cost-effectiveness of the test, and ensuring the safety and accuracy of the test process.

[0036] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for checking the differential flow rate and breaking time of a differential relay, characterized in that: The following steps are involved: S1: Remove the secondary wires of the current transformer: remove the secondary wires A431, B431, C431, and N431 of the 3LH current transformer on the differential relay; S2: Wiring: The current wires of the comprehensive protection tester are connected to the differential relay A, B, C, and N phases according to yellow, green, red, and black respectively; S3: Protection on / off control word setting: Enter the protection on / off control word of the differential protection relay through the key and exit all protections; S4: Time-limited overcurrent protection parameter setting: adjust the high-voltage side action value from 45.8A to 20A to facilitate testing using a comprehensive protection tester; S5: Protection throw-in / out state adjustment: adjust the high-voltage side action value protection throw-in / out control from the out state to the engaged state. This channel is the only engaged channel. S6: Current test and time comparison: Use a comprehensive protection tester to pass a 20A current to detect the differential action, and compare the action time detected by the comprehensive protection tester with the action time displayed by the differential relay; S7: Repeat the test: Repeat step S6, but adjust the high-voltage side action value to 30A and 40A respectively to confirm the differential action; S8: High current test: Use a high current generator to adjust a current of 45.8A, and pass it into phases A, B, and C respectively, confirm that the differential relay operates and the vacuum circuit breaker trips, and confirm the operation time displayed by the differential relay.

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