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, and the method comprises the steps: obtaining the power variable data of a three-terminal optical difference line protection device and a measurement and control device, and uploading the power variable data to a main station corresponding to the protection device and the measurement and control device for data interaction; detecting the operation state of each winding based on the power variable data in combination with a first judgment logic; and judging an on-load test result based on the detection result in combination with the second judgment logic. The polarity and the transformation ratio of the current loop are combined, the polarity of the current loop protected by the three-terminal optical difference line is judged by using the power, the reliability of the remote on-load test of the three-terminal optical difference line protection is improved, and the angle measurement error is reduced.

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] Differential protection for three-terminal transmission lines is the main protection system, capable of quickly isolating faults and effectively protecting primary equipment from fault current surges. The polarity and transformation ratio of the current loop are crucial components of three-terminal differential protection, affecting the correctness of its operation. Similarly, errors in the polarity and transformation ratio of the current loop can influence the direction and magnitude of power, leading to an imbalance between active and reactive power in the power system and impacting the assessment of power flow.

[0003] The conventional method for remote load testing of three-terminal optical differential line protection is based on the angle of current and substation voltage. This method is unreliable, has a large error in angle measurement, and fails to make a comprehensive judgment from the perspective of the entire power system. In addition, since the substation data is transmitted through the remote motor, it relies too much on the communication channel of the remote motor. 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, which solves the problems of unreliability and large angle measurement errors in existing remote load testing methods for 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, comprising:

[0009] Acquire power variable data of the three-terminal optical differential line protection device and the measurement and control device, and upload the power variable data to the master station corresponding to the protection device and the measurement and control device for data interaction;

[0010] Based on the power variable data and the first judgment logic, the operating status of each winding is detected;

[0011] The load test result is determined based on the detection results and the second judgment logic.

[0012] As a preferred embodiment of the remote load testing method for three-terminal optical differential line protection described in this invention, the method for obtaining power variable data of the three-terminal optical differential line protection device and the measurement and control device includes: obtaining the voltage, current phase and amplitude of the protection device and the measurement and control device; the three-terminal optical differential lines are M side, N side and T side respectively.

[0013] Calculate the active and reactive power of the line based on the voltage, current phase, and amplitude.

[0014] The active power of the line is expressed as:

[0015]

[0016] The reactive power of a line is expressed as:

[0017]

[0018] Where U is the line voltage and I is the phase current. Npt represents the angle by which the in-phase voltage leads the current, Nct represents the voltage transformation ratio, and Nct represents the current transformation ratio.

[0019] As a preferred embodiment of the remote load testing method for three-terminal optical differential line protection described in this invention, the method includes: detecting the operating status of each winding based on the power variable data combined with the first judgment logic, including:

[0020] If the active power of the 110kV line bay on any side is equal to the negative of the sum of the power of all bays on the bus, then it is determined that the voltage and current secondary circuits used in the bay on any side are correct.

[0021] Once it is confirmed that the voltage and current secondary circuits on either side are used correctly, the changes in active and reactive power on each side are calculated.

[0022] As a preferred embodiment of the remote load testing method for three-terminal optical differential line protection described in this invention, it further includes:

[0023] The master station corresponding to the protection device is the information protection master station, and the master station corresponding to the measurement and control device is the OCS master station;

[0024] The change in active power at the Baoxin master station is expressed as follows:

[0025] ΔP=PM+PN+PT

[0026] Wherein, PM represents the active power on the M side of the Baoxin master station, and PN represents the active power on the N side of the Baoxin master station.

[0027] Rate, PT is the power of the main station T side;

[0028] The reactive power change of the main station is expressed as follows:

[0029] ΔQ=QM+QN+QT

[0030] Wherein, QM is the reactive power on the M side of the Baoxin master station, QN is the reactive power on the N side of the Baoxin master station, and QT is the reactive power on the T side of the Baoxin master station.

[0031] As a preferred embodiment of the remote load testing method for three-terminal optical differential line protection described in this invention, it further includes:

[0032] The change in active power at the OCS master station is expressed as follows:

[0033] ΔPo=PMo+PNo+PTo

[0034] Wherein, PMo is the active power on the M side of the OCS master station, PNo is the active power on the N side of the OCS master station, and PTo ​​is the active power on the T side of the OCS master station.

[0035] The reactive power change of the OCS master station is expressed as:

[0036] ΔQo=QMo+QNo+QTo

[0037] Wherein, QMo is the reactive power on the M side of the OCS master station, QNo is the reactive power on the N side of the OCS master station, and QTo is the reactive power on the T side of the OCS master station.

[0038] As a preferred embodiment of the remote load testing method for three-terminal optical differential line protection described in this invention, it further includes:

[0039] when and If the power variable data of the three-terminal optical differential line protection device is normal, the secondary current circuit winding is operating normally; otherwise, the power of the secondary current circuit windings of the three-terminal optical differential line is inconsistent, the winding is operating abnormally, and manual on-site inspection is required.

[0040] As a preferred embodiment of the remote load testing method for three-terminal optical differential line protection described in this invention, the load testing result is determined based on the detection result combined with the second judgment logic, including:

[0041] When the secondary current circuit winding is operating normally, if the active power and reactive power on the three sides are balanced, the load test result is normal; if any power is unbalanced, the load test result is abnormal, and there is an error in the polarity or turns ratio of the current and voltage circuit.

[0042] Secondly, this invention provides a remote load testing system for three-terminal optical differential line protection, comprising:

[0043] The data acquisition module is used to acquire power variable data of the secondary current loop protection device and the measurement and control device, and upload the power variable data to the main station corresponding to the protection device and the measurement and control device for data interaction.

[0044] The first judgment module is used to detect each winding of the secondary current circuit based on the power variable data and the first judgment logic.

[0045] The second judgment module is used to judge the load test result based on the detection result and the second judgment logic.

[0046] Thirdly, the present invention provides a computing device, comprising:

[0047] Memory and processor;

[0048] 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.

[0049] 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.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention combines the polarity and transformation ratio of the current loop, and uses power to determine the polarity of the current loop of the three-terminal optical differential line protection, thereby improving the reliability of remote load testing of the three-terminal optical differential line protection and reducing the angle measurement error. Attached Figure Description

[0051] 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:

[0052] 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;

[0053] Figure 2 This is a circuit diagram of a remote load testing method and system for three-terminal optical differential line protection according to an embodiment of the present invention;

[0054] Figure 3 This is a schematic diagram of the M-side winding of a remote load testing method and system for three-terminal optical differential line protection according to an embodiment of the present invention;

[0055] Figure 4 This is a schematic diagram of the active power on three sides of a remote load testing method and system for three-terminal optical differential line protection according to an embodiment of the present invention. Detailed Implementation

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] Example 1

[0063] Reference Figures 1-4 As one embodiment of the present invention, this embodiment provides a remote load testing method for three-terminal optical differential line protection, comprising:

[0064] S1: Obtain the power variable data of the three-terminal optical differential line protection device and the measurement and control device, and upload the power variable data to the master station corresponding to the protection device and the measurement and control device for data interaction;

[0065] Furthermore, acquiring power variable data for the three-terminal optical differential line protection device and the measurement and control device includes: acquiring the voltage, current phase, and amplitude of the protection device and the measurement and control device; the three-terminal optical differential lines are the M side, N side, and T side;

[0066] Calculate the active and reactive power of the line based on the voltage, current phase, and amplitude.

[0067] The active power of the line is expressed as:

[0068]

[0069] The reactive power of a line is expressed as:

[0070]

[0071] Where U is the line voltage and I is the phase current. Npt represents the angle by which the in-phase voltage leads the current, Nct represents the voltage transformation ratio, and Nct represents the current transformation ratio.

[0072] In an optional embodiment, when both active power and reactive power are not less than 0, When both active power and reactive power are less than 0 When both active power and reactive power are not greater than 0 When both active power and reactive power are greater than 0

[0073] S2: Detect the operating status of each winding based on power variable data and the first judgment logic;

[0074] Furthermore, based on power variable data and the first judgment logic, the operating status of each winding is detected, including:

[0075] If the active power of any 110kV line bay is equal to the negative of the sum of the power of all bays on the bus, then the voltage and current secondary circuits used in any bay are correct.

[0076] Once it is confirmed that the voltage and current secondary circuits on either side are used correctly, the changes in active and reactive power on each side are calculated.

[0077] like Figure 3 As shown, in an optional embodiment, if the M side is an existing substation and the N and T sides are newly built substations, the active power of the 110kV line bay on the M side is equal to the negative of the sum of the power of all bays on the bus. That is, when PM = -(P1 + P2 + P3) is satisfied, it is determined that the voltage and current secondary circuit of the bay on the M side is correct. After it is determined that the voltage and current secondary circuit of the bay on the M side is correct, the subsequent calculations are based on the M side.

[0078] Furthermore, this also includes:

[0079] The master station corresponding to the protection device is the information protection master station, and the master station corresponding to the measurement and control device is the OCS master station;

[0080] The change in active power at the Baoxin master station is expressed as follows:

[0081] ΔP=PM+PN+PT

[0082] Wherein, PM is the active power on the M side of the Baoxin master station, PN is the active power on the N side of the Baoxin master station, and PT is the power on the T side of the Baoxin master station;

[0083] The reactive power change of the main station is expressed as follows:

[0084] ΔQ=QM+QN+QT

[0085] Wherein, QM is the reactive power on the M side of the Baoxin master station, QN is the reactive power on the N side of the Baoxin master station, and QT is the reactive power on the T side of the Baoxin master station.

[0086] Furthermore, this also includes:

[0087] The change in active power at the OCS master station is expressed as follows:

[0088] ΔPo=PMo+PNo+PTo

[0089] Wherein, PMo is the active power on the M side of the OCS master station, PNo is the active power on the N side of the OCS master station, and PTo ​​is the active power on the T side of the OCS master station.

[0090] The reactive power change of the OCS master station is expressed as:

[0091] ΔQo=QMo+QNo+QTo

[0092] Wherein, QMo is the reactive power on the M side of the OCS master station, QNo is the reactive power on the N side of the OCS master station, and QTo is the reactive power on the T side of the OCS master station.

[0093] Furthermore, this also includes:

[0094] when and If the power variable data of the three-terminal optical differential line protection device is normal, the secondary current circuit winding is operating normally; otherwise, the power of the secondary current circuit windings of the three-terminal optical differential line is inconsistent, the winding is operating abnormally, and manual on-site inspection is required.

[0095] S3: Determine the load test result based on the detection result and the second judgment logic;

[0096] Furthermore, the load test results are determined based on the detection results combined with the second judgment logic, including:

[0097] When the secondary current circuit winding is operating normally, if the active power and reactive power on the three sides are balanced, the load test result is normal; if any power is unbalanced, the load test result is abnormal, and there is an error in the polarity or turns ratio of the current and voltage circuit.

[0098] In one alternative implementation, when ΔP = 0, the active power on all three sides is balanced, and when ΔQ = 0, the reactive power on all three sides is balanced.

[0099] 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.

[0100] This embodiment provides a remote load testing system for three-terminal optical differential line protection, comprising:

[0101] The data acquisition module is used to acquire power variable data of the secondary current loop protection device and the measurement and control device, and upload the power variable data to the main station corresponding to the protection device and the measurement and control device for data interaction.

[0102] The first judgment module is used to detect each winding of the secondary current circuit based on power variable data and the first judgment logic.

[0103] The second judgment module is used to judge the load test result based on the detection result and the second judgment logic.

[0104] This embodiment also provides a computing device applicable to the remote load testing method for three-terminal optical differential line protection, including:

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] Example 2

[0110] Referring to Table 1, which is an embodiment of the present invention, this embodiment differs from the first embodiment in that it verifies the beneficial effects of the present invention through specific testing.

[0111] The test results are shown in Table 1:

[0112] Table 1 Test Results

[0113]

[0114] As can be seen from Table 1, this invention combines the polarity and transformation ratio of the current loop and uses power to determine the polarity of the current loop of the three-terminal optical differential line protection, thereby improving the reliability of remote load testing of the three-terminal optical differential line protection and reducing the angle measurement error.

[0115] 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 power variable data of the three-terminal optical differential line protection device and the measurement and control device, and upload the power variable data to the master station corresponding to the protection device and the measurement and control device for data interaction; Based on the power variable data and the first judgment logic, the operating status of each winding is detected; The load test result is determined based on the detection results and the second judgment logic.

2. The remote load testing method for three-terminal optical differential line protection as described in claim 1, characterized in that, Acquiring power variable data for the three-terminal optical differential line protection device and the measurement and control device includes: acquiring the voltage, current phase, and amplitude of the protection device and the measurement and control device; the three-terminal optical differential lines are M-side, N-side, and T-side, respectively. Calculate the active and reactive power of the line based on the voltage, current phase, and amplitude. The active power of the line is expressed as: The reactive power of a line is expressed as: Where U is the line voltage and I is the phase current. Npt represents the angle by which the in-phase voltage leads the current, and Nct represents the voltage transformation ratio and the current transformation ratio.

3. The remote load testing method for three-terminal optical differential line protection as described in claim 2, characterized in that, Based on the power variable data and the first judgment logic, the operating status of each winding is detected, including: If the active power of the 110kV line bay on any side is equal to the negative of the sum of the power of all bays on the bus, then it is determined that the voltage and current secondary circuits used in the bay on any side are correct. Once it is confirmed that the voltage and current secondary circuits on either side are used correctly, the changes in active and reactive power on each side are calculated.

4. The remote load testing method for three-terminal optical differential line protection as described in claim 1 or 3, characterized in that, Also includes: The master station corresponding to the protection device is the information protection master station, and the master station corresponding to the measurement and control device is the OCS master station; The change in active power at the Baoxin master station is expressed as follows: ΔP=PM+PN+PT Wherein, PM is the active power on the M side of the Baoxin master station, PN is the active power on the N side of the Baoxin master station, and PT is the power on the T side of the Baoxin master station; The reactive power change of the main station is expressed as follows: ΔQ=QM+QN+QT Wherein, QM is the reactive power on the M side of the Baoxin master station, QN is the reactive power on the N side of the Baoxin master station, and QT is the reactive power on the T side of the Baoxin master station.

5. The remote load testing method for three-terminal optical differential line protection as described in claim 4, characterized in that, Also includes: The change in active power at the OCS master station is expressed as follows: ΔPo=PMo+PNo+PTo Wherein, PMo is the active power on the M side of the OCS master station, PNo is the active power on the N side of the OCS master station, and PTo ​​is the active power on the T side of the OCS master station. The reactive power change of the OCS master station is expressed as: ΔQo=QMo+QNo+QTo Wherein, QMo is the reactive power on the M side of the OCS master station, QNo is the reactive power on the N side of the OCS master station, and QTo is the reactive power on the T side of the OCS master station.

6. The remote load testing method for three-terminal optical differential line protection as described in claim 5, characterized in that, Also includes: when and If the power variable data of the three-terminal optical differential line protection device is normal, the secondary current circuit winding is operating normally; otherwise, the power of the secondary current circuit windings of the three-terminal optical differential line is inconsistent, the winding is operating abnormally, and manual on-site inspection is required.

7. The remote load testing method for three-terminal optical differential line protection as described in claim 6, characterized in that, Based on the detection results and combined with the second judgment logic, the load test results are judged as follows: When the secondary current circuit winding is operating normally, if the active power and reactive power on the three sides are balanced, the load test result is normal; if any power is unbalanced, the load test result is abnormal, and there is an error in the polarity or turns ratio of the current and voltage circuit.

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 power variable data of the secondary current loop protection device and the measurement and control device, and upload the power variable data to the main station corresponding to the protection device and the measurement and control device for data interaction. The first judgment module is used to detect each winding of the secondary current circuit based on the power variable data and the first judgment logic. The second judgment module is used to judge the load test result based on the detection result and the second judgment logic.

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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