Three-terminal optical difference line protection remote on-load test method and system

Abstract

The invention discloses a three-terminal optical difference line protection remote on-load test method and system. The method comprises the steps of obtaining three-terminal optical difference line current data and a circuit breaker position corresponding to a three-terminal optical difference line; performing first-layer logic judgment based on the current data and the position of the circuit breaker, and performing second-layer logic judgment based on a first-layer logic judgment result in combination with the current data; and determining a three-terminal optical difference line protection remote on-load test result according to the double-layer logic judgment result. According to the invention, remote on-load testing is carried out on the three-terminal optical fiber differential protection device through double-layer current calculation, and meanwhile, an on-load testing result can be output, so that the testing precision is improved, and a worker can conveniently carry out fault detection.

Description

Technical Field

[0001] This invention relates to the technical field of relay protection, and in particular to a method and system for remote load testing of three-terminal optical differential line protection. Background Technology

[0002] In high-voltage power grids, with the development of power systems and the increase in load density, high-voltage, heavy-load three-terminal T-type transmission lines are frequently encountered due to economic considerations of equipment investment and difficulties in land acquisition. These lines often connect large power plants and large systems, requiring rapid fault clearing. Currently, three-terminal fiber optic differential protection devices are mostly used to protect these transmission lines, enabling rapid fault clearing and protecting primary equipment of the power system from the impact of fault currents. The polarity and transformation ratio of the current loop are crucial components in three-terminal fiber optic differential line protection, affecting the correctness of the protection operation.

[0003] Load testing is a crucial method to ensure the correct phase sequence and polarity of current in secondary equipment within a substation. For newly installed protection devices or those with modified secondary circuits, load current must be used to verify the polarity, turns ratio, and correctness of the secondary circuit of each current transformer (CT) winding before commissioning to prevent malfunctions. Compared to remote load testing of conventional two-terminal optical differential line protection, load testing of three-terminal optical differential line protection has the following characteristics: the algorithm changes. When the transmission line is upgraded from two-terminal to three-terminal, the original calculation method for remote load testing of optical fiber differential protection devices is no longer applicable to three-terminal optical differential protection. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the aforementioned existing problems, the present invention is proposed.

[0006] Therefore, this invention provides a method and system for remote load testing of three-terminal optical differential line protection to solve the problem that the existing two-segment optical differential remote load testing method does not conform to the load testing logic of three-terminal optical differential line protection.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] In a first aspect, embodiments of the present invention provide a method for remote load testing of three-terminal optical differential line protection, including: acquiring current data of the three-terminal optical differential line and the location of the circuit breaker corresponding to the three-terminal optical differential line;

[0009] A first-level logic judgment is made based on the current data and the circuit breaker location, and a second-level logic judgment is made based on the result of the first-level logic judgment and the current data.

[0010] The results of the remote load test for the three-terminal optical differential line protection are determined based on the results of the dual-layer logic judgment.

[0011] As a preferred embodiment of the remote load testing method for three-terminal optical differential line protection described in this invention, acquiring the current data of the three-terminal optical differential line and the location of the circuit breaker corresponding to the three-terminal optical differential line includes:

[0012] The obtained three-terminal optical differential line current data are the current values ​​of the line protection devices on the M side, N side and T side. The M side corresponds to the first circuit breaker position DL1, the N side corresponds to the second circuit breaker position DL2, and the T side corresponds to the third circuit breaker position DL3.

[0013] Based on the current values ​​of the line protection devices on the M side, N side, and T side, the differential current values ​​on the M side, N side, and T side are calculated using differential current; the differential current value on the M side is... The differential current value on the N side is The differential current value on the T side is

[0014] As a preferred embodiment of the remote load testing method for three-terminal optical differential line protection described in this invention, the first-level logic judgment based on the current data and the circuit breaker position includes:

[0015] When DL1=0, DL2=1, and DL3=1, the circuit breaker on side M is in the open state. If the current loop on the M side is in normal condition, then it is in an abnormal condition.

[0016] like The N-side current loop is in an abnormal state; otherwise, it is in a normal state.

[0017] like If the current loop on side T is in an abnormal state, then it is in a normal state.

[0018] Where In is the rated current.

[0019] As a preferred embodiment of the remote load test method for three-terminal optical differential line protection described in this invention, it further includes: when DL1=1, DL2=0, and DL3=1, the circuit breaker on the M side is in the open state.

[0020] like The N-side current loop is in a normal state; otherwise, it is in an abnormal state.

[0021] like If the current loop on the M side is in an abnormal state, then it is in a normal state.

[0022] like If the current loop on side T is in an abnormal state, then it is in a normal state.

[0023] As a preferred embodiment of the remote load test method for three-terminal optical differential line protection described in this invention, it further includes: when DL1=1, DL2=1, and DL3=0, the circuit breaker on the M side is in the open state.

[0024] like If the current loop on side T is in a normal state, then it is in an abnormal state.

[0025] like If the current loop on the M side is in an abnormal state, then it is in a normal state.

[0026] like The N-side current loop is in an abnormal state; otherwise, it is in a normal state.

[0027] When all three current loops of the MNT are in normal condition, the second level of logic judgment is performed. If any one of the three current loops of the MNT is in an abnormal condition, the load test ends.

[0028] As a preferred embodiment of the remote load testing method for three-terminal optical differential line protection described in this invention, the second-level logic judgment based on the first-level logic judgment result combined with the current data includes:

[0029] If all three current loops of MNT are in normal condition, when any two circuit breakers are closed and the remaining one is open, if If the load test is normal, it is considered normal; otherwise, the load test is abnormal. IDa is the differential current.

[0030] As a preferred embodiment of the remote load testing method for three-terminal optical differential line protection described in this invention, it further includes: if the current loops on all three sides of the MNT are in normal condition and the circuit breakers on all three sides are in closed condition.

[0031] When the ID on each side approaches or equals 0, the load test is considered normal; otherwise, the polarity of the current on all three sides is considered incorrect, and the load test is terminated.

[0032] When the sum of the ID values ​​on all sides approaches or equals 0, the load test is considered normal; otherwise, the polarity of the current on all three sides is considered incorrect, and the load test is terminated.

[0033] in, and IM, IN, and IT represent the load currents on each side.

[0034] like If the polarity of the M side is reversed, check the secondary circuit of the M side; similarly, if the differential current value is equal to twice the load current of the other sides, check the secondary circuit of each side.

[0035] Secondly, the present invention provides a remote load testing system for three-terminal optical differential line protection, comprising:

[0036] The data acquisition module is used to acquire the current data of the three-terminal optical differential line and the location of the circuit breaker corresponding to the three-terminal optical differential line.

[0037] The logic judgment module is used to perform a first-level logic judgment based on the current data and the circuit breaker position, and to perform a second-level logic judgment based on the result of the first-level logic judgment and the current data.

[0038] The test result determination module is used to determine the remote load test result of the three-terminal optical differential line protection based on the two-layer logic judgment result.

[0039] Thirdly, the present invention provides a computing device, comprising:

[0040] Memory and processor;

[0041] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, they implement the steps of the remote load test method for the three-terminal optical differential line protection.

[0042] Fourthly, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the remote load testing method for the three-terminal optical differential line protection.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention can perform remote load testing on a three-terminal fiber optic differential protection device through dual-layer current calculation, and can also output the load test results, which improves the test accuracy and facilitates fault detection by the staff. Attached Figure Description

[0044] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0045] Figure 1 This is a flowchart of a method and system for remote load testing of three-terminal optical differential line protection according to an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of a three-terminal optical differential circuit according to an embodiment of the present invention, which describes a remote load testing method and system for three-terminal optical differential circuit protection. Detailed Implementation

[0047] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0048] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0049] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0050] This invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0051] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0052] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0053] Example 1

[0054] Reference Figure 1 As one embodiment of the present invention, this embodiment provides a remote load testing method for three-terminal optical differential line protection, comprising:

[0055] S1: Obtain the current data of the three-terminal optical differential line and the location of the circuit breaker corresponding to the three-terminal optical differential line.

[0056] S2: Perform the first-level logic judgment based on the current data and the circuit breaker position, and perform the second-level logic judgment based on the result of the first-level logic judgment and the current data.

[0057] S3: Determine the remote load test result of the three-terminal optical differential line protection based on the result of the two-layer logic judgment;

[0058] Furthermore, the system acquires the current data of the three-terminal optical differential line and the location of the corresponding circuit breaker, including:

[0059] The three-terminal optical differential line current data are obtained as the current values ​​of the line protection devices on the M side, N side and T side. The M side corresponds to the first circuit breaker position DL1, the N side corresponds to the second circuit breaker position DL2, and the T side corresponds to the third circuit breaker position DL3.

[0060] Based on the current values ​​of the line protection devices on the M, N, and T sides, the differential current values ​​on the M, N, and T sides are calculated using differential current calculations; the differential current value on the M side is... The differential current value on the N side is The differential current value on the T side is

[0061] Furthermore, the first-level logic judgment based on current data and circuit breaker location includes:

[0062] When DL1=0, DL2=1, and DL3=1, the circuit breaker on side M is in the open state. If the current loop on the M side is in normal condition, then it is in an abnormal condition.

[0063] like The N-side current loop is in an abnormal state; otherwise, it is in a normal state.

[0064] like If the current loop on side T is in an abnormal state, then it is in a normal state.

[0065] Where In is the rated current.

[0066] It should be noted that in this embodiment, the current loop error is set to 0.02 times the rated current.

[0067] Furthermore, it also includes the following: when DL1=1, DL2=0, and DL3=1, the circuit breaker on the M side is in the open state;

[0068] like The N-side current loop is in a normal state; otherwise, it is in an abnormal state.

[0069] like If the current loop on the M side is in an abnormal state, then it is in a normal state.

[0070] like If the current loop on side T is in an abnormal state, then it is in a normal state.

[0071] Furthermore, it also includes the following: when DL1=1, DL2=1, and DL3=0, the circuit breaker on the M side is in the open state;

[0072] like If the current loop on side T is in a normal state, then it is in an abnormal state.

[0073] like If the current loop on the M side is in an abnormal state, then it is in a normal state.

[0074] like The N-side current loop is in an abnormal state; otherwise, it is in a normal state.

[0075] When all three current loops of the MNT are in normal condition, the second level of logic judgment is performed. If any one of the three current loops of the MNT is in an abnormal condition, the load test ends.

[0076] Furthermore, the second-level logic judgment, based on the result of the first-level logic judgment combined with the current data, includes:

[0077] If all three current loops of MNT are in normal condition, when any two circuit breakers are closed and the remaining one is open, if If the load test is normal, it is considered normal; otherwise, the load test is abnormal. IDa is the differential current.

[0078] It should be noted that due to the presence of capacitive current in the line, there will be errors in the measurement results. In this embodiment, the measurement error is set to be no greater than ±0.02In.

[0079] Furthermore, this also includes: if all three current loops of MNT are in normal condition and all three circuit breakers are in closed condition;

[0080] When the ID on each side approaches or equals 0, the load test is considered normal; otherwise, the polarity of the current on all three sides is considered incorrect, and the load test is terminated.

[0081] When the sum of the ID values ​​on all sides approaches or equals 0, the load test is considered normal; otherwise, the polarity of the current on all three sides is considered incorrect, and the load test is terminated.

[0082] in, and IM, IN, and IT represent the load currents on each side.

[0083] like If the polarity of the M side is reversed, check the secondary circuit of the M side; similarly, if the differential current value is equal to twice the load current of the other sides, check the secondary circuit of each side.

[0084] In an optional embodiment, the voltage of the three-terminal optical differential line protection device is 110kV.

[0085] The above is a schematic scheme of a remote load testing method for three-terminal optical differential line protection according to this embodiment. It should be noted that the technical solution of this remote load testing system for three-terminal optical differential line protection belongs to the same concept as the technical solution of the aforementioned remote load testing method for three-terminal optical differential line protection. Details not described in detail in this embodiment can be found in the description of the aforementioned remote load testing method for three-terminal optical differential line protection.

[0086] This embodiment provides a remote load testing system for three-terminal optical differential line protection, comprising:

[0087] The data acquisition module is used to acquire the current data of the three-terminal optical differential line and the location of the circuit breaker corresponding to the three-terminal optical differential line.

[0088] The logic judgment module is used to perform the first-level logic judgment based on current data and circuit breaker position, and to perform the second-level logic judgment based on the result of the first-level logic judgment and the current data.

[0089] The test result determination module is used to determine the remote load test results of the three-terminal optical differential line protection based on the results of the two-layer logic judgment.

[0090] This embodiment also provides a computing device applicable to the remote load testing method for three-terminal optical differential line protection, including:

[0091] The system includes a memory and a processor. The memory stores computer-executable instructions, and the processor executes these instructions to implement the remote load testing method for three-terminal optical differential line protection as proposed in the above embodiments.

[0092] This embodiment also provides a storage medium storing a computer program, which, when executed by a processor, implements the method for remote load testing of three-terminal optical differential line protection as proposed in the above embodiment.

[0093] The storage medium proposed in this embodiment and the remote load testing method for three-terminal optical differential line protection proposed in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0094] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0095] Example 2

[0096] Reference Figure 1 This is one embodiment of the present invention. Unlike the first embodiment, this embodiment verifies the beneficial effects of the present invention through specific testing.

[0097] In this embodiment, the current values ​​of the line protection devices on the M, N, and T sides are obtained through the information protection substation; in this embodiment, the circuit breaker positions of DL1, DL2, and DL3 are respectively: DL1=1, DL2=0, DL3=1. The results of the remote load test of the three-terminal optical differential line protection are shown in Table 1:

[0098] Table 1 Test Results

[0099]

[0100] As can be seen from Table 1, this invention can perform remote load testing on a three-terminal fiber optic differential protection device through dual-layer current calculation, and can also output the load test results, which improves the test accuracy and facilitates fault detection by staff.

[0101] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for remote load testing of three-terminal optical differential line protection, characterized in that, include: Acquire the current data of the three-terminal optical differential line and the location of the corresponding circuit breaker of the three-terminal optical differential line; A first-level logic judgment is made based on the current data and the circuit breaker location, and a second-level logic judgment is made based on the result of the first-level logic judgment and the current data. The results of the remote load test for the three-terminal optical differential line protection are determined based on the results of the dual-layer logic judgment.

2. The remote load testing method for three-terminal optical differential line protection as described in claim 1, characterized in that, Obtain the current data of the three-terminal optical differential line and the location of the corresponding circuit breaker for the three-terminal optical differential line, including: The obtained three-terminal optical differential line current data are the current values ​​of the line protection devices on the M side, N side and T side. The M side corresponds to the first circuit breaker position DL1, the N side corresponds to the second circuit breaker position DL2, and the T side corresponds to the third circuit breaker position DL3. Based on the current values ​​of the line protection devices on the M side, N side, and T side, the differential current values ​​on the M side, N side, and T side are calculated using differential current; the differential current value on the M side is... The differential current value on the N side is The differential current value on the T side is 3. The remote load testing method for three-terminal optical differential line protection as described in claim 2, characterized in that, The first-level logic judgment based on the current data and the circuit breaker location includes: When DL1=0, DL2=1, and DL3=1, the circuit breaker on side M is in the open state. If the current loop on the M side is in normal condition, then it is in an abnormal condition; otherwise, it is in an abnormal condition. like The N-side current loop is in an abnormal state; otherwise, it is in a normal state. like If the current loop on side T is in an abnormal state, then it is in a normal state. Where In is the rated current.

4. The remote load testing method for three-terminal optical differential line protection as described in claim 3, characterized in that, Also includes: When DL1=1, DL2=0, and DL3=1, the circuit breaker on the M side is in the open state; like The N-side current loop is in a normal state; otherwise, it is in an abnormal state. like If the current loop on the M side is in an abnormal state, then it is in a normal state. like If the current loop on side T is in an abnormal state, then it is in a normal state.

5. The remote load testing method for three-terminal optical differential line protection as described in claim 4, characterized in that, Also includes: When DL1=1, DL2=1, and DL3=0, the circuit breaker on the M side is in the open state; like If the current loop on side T is in a normal state, then it is in an abnormal state. like If the current loop on the M side is in an abnormal state, then it is in a normal state. like The N-side current loop is in an abnormal state; otherwise, it is in a normal state. When all three current loops of the MNT are in normal condition, the second level of logic judgment is performed. If any one of the three current loops of the MNT is in an abnormal condition, the load test ends.

6. The remote load testing method for three-terminal optical differential line protection as described in claim 5, characterized in that, The second layer of logic judgment, based on the result of the first layer of logic judgment and the current data, includes: If all three current loops of MNT are in normal condition, when any two circuit breakers are closed and the remaining one is open, if If the load test is normal, it is considered normal; otherwise, the load test is abnormal. IDa is the differential current.

7. The remote load testing method for three-terminal optical differential line protection as described in claim 6, characterized in that, Also includes: If all three current loops of MNT are in normal condition and all three circuit breakers are in closed condition; When the IDs on each side approach or equal to 0, the load test is considered normal. Otherwise, the polarity of the current on all three sides is determined to be incorrect, and the load test is terminated. When the sum of the IDs on all sides approaches or equals 0, the load test is considered normal. Otherwise, the polarity of the current on all three sides is determined to be incorrect, and the load test is terminated. in, and IM, IN, and IT represent the load currents on each side. like If the polarity of the M side is reversed, check the secondary circuit of the M side; similarly, if the differential current value is equal to twice the load current of the other sides, check the secondary circuit of each side.

8. A remote load testing system for three-terminal optical differential line protection, characterized in that, include: The data acquisition module is used to acquire the current data of the three-terminal optical differential line and the location of the circuit breaker corresponding to the three-terminal optical differential line. The logic judgment module is used to perform a first-level logic judgment based on the current data and the circuit breaker position, and to perform a second-level logic judgment based on the result of the first-level logic judgment and the current data. The test result determination module is used to determine the remote load test result of the three-terminal optical differential line protection based on the two-layer logic judgment result.

9. An electronic device, comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, they implement the steps of the remote load test method for three-terminal optical differential line protection as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing computer-executable instructions that, when executed by a processor, implement the steps of the remote load testing method for three-terminal optical differential line protection as described in any one of claims 1 to 7.

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