A method, system and medium for identifying the state of a closing resistor

Abstract

The present invention discloses a method, system and medium for identifying the state of a closing resistor, which includes obtaining fault recording data; extracting the waveform segments with current mutations from the fault recording data to obtain a number of waveform segment data; selecting any one of the waveform segment data and calculating the corresponding resistance value curve in this waveform segment data, traversing a number of waveform segment data to obtain a number of resistance value curves; comparing the number of the resistance value curves with the rated closing resistor resistance value curve respectively to obtain the state of the closing resistor. The beneficial effect of the present invention is that by monitoring the current mutation data of the fault recording data in real time and converting it into a comparison method between the resistance value curve and the rated resistance value curve, the state of the closing resistor is judged, realizing the real-time monitoring of the state of the closing resistor, and avoiding the occurrence of accidents such as insulation discharge or breakdown of the closing resistor.

Description

Technical Field

[0001] The present invention relates to the technical field of closing resistor state recognition, and more specifically, to a method, a system, and a medium for recognizing the state of a closing resistor. Background Art

[0002] With the development of the power grid, high-voltage and long-distance power transmission are becoming more and more common. For a 500 kV long transmission line, in order to limit the overvoltage generated by switching on and off no-load lines in the power system, a closing resistor is installed on the circuit breaker to protect the electrical equipment of the power grid. The closing resistor is withdrawn before the main contacts are closed when the circuit breaker is opened, and is inserted first when the circuit breaker is closed. When the main contacts are closed, it is short-circuited and withdrawn, thus effectively protecting the equipment.

[0003] With the expansion of the operation scale of 500 kV circuit breakers, problems often occur with the closing resistors, resulting in circuit breaker damage incidents. In the past two years, the State Grid Corporation has had a total of 16 insulation failures of circuit breakers with closing resistors. Among them, 4 were caused by defects in the closing resistor itself, and the other 12 were caused by foreign objects inside the tank, insulating parts, assembly defects of the circuit breaker body and the transmission part. The risk of failure of the closing resistor of the circuit breaker under the combined action of mechanical shock effect, overvoltage caused by short circuit, and thermal accumulation effect has also increased significantly.

[0004] Currently, at home and abroad, general attention is paid to the mechanical state of the circuit breaker, but less attention is paid to the insulation defects of the circuit breaker, especially less research on the closing resistor. However, once insulation discharge or breakdown occurs in the closing resistor, it will cause serious consequences. Therefore, in the prior art, due to the neglect of the insulation of the circuit breaker, it is easy to cause insulation discharge or breakdown of the closing resistor, and in serious cases, serious accidents will occur.

[0005] In view of this, the present application is specifically proposed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that in the prior art, the attention to the insulation defects of the circuit breaker is neglected, which may cause insulation discharge or breakdown of the closing resistor and serious accidents. The purpose is to provide a method, a system, and a medium for recognizing the state of a closing resistor to realize the process of real-time monitoring of the state of the closing resistor and avoid the occurrence of accidents of insulation discharge or breakdown of the closing resistor.

[0007] The present invention is achieved by the following technical solutions:

[0008] A method for recognizing the state of a closing resistor, the method steps include:

[0009] Obtain fault recording data;

[0010] Extract the waveform segments with current mutation from the fault recording data to obtain a number of waveform segment data;

[0011] Select any waveform segment data, and calculate the corresponding resistance curve in this waveform segment data. Traverse several waveform segment data to obtain several resistance curves;

[0012] Compare several of the resistance curves with the rated closing resistor resistance curve respectively to obtain the state of the closing resistor.

[0013] When traditionally detecting a circuit breaker, usually more attention is paid to the mechanical state of the circuit breaker, ignoring the harm caused by the insulation defect of the circuit breaker. Especially in the closing resistor, if its insulation defect is not detected, when the closing resistor generates insulation discharge or breakdown, serious accidents are likely to occur; The present invention provides a method for identifying the state of a closing resistor. By real-time monitoring the current mutation data of the fault recording data and converting it into a method of comparing the resistance curve with the rated resistance curve, the state of the closing resistor is judged, realizing the process of real-time monitoring of the state of the closing resistor, and avoiding the occurrence of accidents such as insulation discharge or breakdown of the closing resistor.

[0014] Preferably, the specific calculation sub-steps of the resistance curve include:

[0015] In the waveform segment data, obtain the voltage and current of each data point;

[0016] Based on the obtained voltage and current, calculate the resistance of this data point. After calculating each data point, obtain the resistance values corresponding to several data points;

[0017] Connect several of the resistance values according to the time sequence of the occurrence of the data points to obtain a resistance curve.

[0018] Preferably, in the waveform segment data, the method for obtaining the voltage is:

[0019] Obtain the first voltage on the waveform segment data line and the second voltage on the adjacent line;

[0020] Perform a difference operation on the first voltage and the second voltage to obtain the voltage.

[0021] Preferably, the discrimination of the state of the closing resistor is: when there is a sudden change in the decline rate of the resistance value of the closing resistor when it is put into the device, the state of the closing resistor is defective.

[0022] Preferably, the sampling frequency of the fault recording data is greater than or equal to 4 kHz.

[0023] Preferably, the waveform segment data starts timing when the current mutates and is the waveform data occurring within 30 ms afterwards.

[0024] The present invention also provides a recognition system for the state of closing resistors, including a data acquisition module, a waveform extraction module, a resistance value curve calculation module, and a state judgment module;

[0025] The data acquisition module is used to acquire fault recording data;

[0026] The waveform extraction module is used to extract the waveform segments with current mutations in the fault recording data to obtain several waveform segment data;

[0027] The resistance value curve calculation module is used to select any one of the waveform segment data and calculate the corresponding resistance value curve in this waveform segment data, and traverse several waveform segment data to obtain several resistance value curves;

[0028] The state judgment module is used to compare several of the resistance value curves with the rated closing resistor resistance value curve respectively to obtain the state of the closing resistor.

[0029] Preferably, the resistance value curve calculation module includes a voltage and current acquisition module, a calculation module, and a connection module;

[0030] The voltage and current acquisition module is used to acquire the voltage and current of each data point in the waveform segment data;

[0031] The calculation module is used to calculate the resistance of this data point based on the obtained voltage and current, and after calculating each data point, obtain the resistance values corresponding to several data points;

[0032] The connection module is used to connect several of the resistance values according to the time sequence of the occurrence of the data points to obtain a resistance value curve.

[0033] Preferably,

[0034] The voltage and current acquisition module further includes a sub-voltage acquisition module and a difference operation module,

[0035] The sub-voltage acquisition module is used to acquire the first voltage on the waveform segment data line and the second voltage on the adjacent line;

[0036] The difference operation module is used to perform a difference operation on the first voltage and the second voltage to obtain the voltage..

[0037] The present invention also provides a computer storage medium, on which a calculation program is stored. When the computer program is executed by a processor, the above-mentioned recognition method is implemented.

[0038] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0039] A method, system, and medium for identifying the state of a closing resistor provided by an embodiment of the present invention monitor the current mutation data of fault recording data in real time, and convert it into a resistance value curve for comparison with the rated resistance value curve to determine the state of the closing resistor, realizing the real-time monitoring of the state of the closing resistor, and avoiding the occurrence of accidents such as insulation discharge or breakdown of the closing resistor. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0041] Figure 1 Schematic diagram of the identification method;

[0042] Figure 2 Schematic diagram of the resistance value curve implemented in the first embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the embodiments and the drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0044] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that the present invention does not have to be implemented with these specific details. In other embodiments, well-known structures, circuits, materials, or methods are not specifically described in order to avoid obscuring the present invention.

[0045] Throughout the specification, the reference to "one embodiment", "embodiment", "one example", or "example" means that the specific features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment", "embodiment", "one example", or "example" that appear throughout the specification do not necessarily all refer to the same embodiment or example. In addition, the specific features, structures, or characteristics can be combined in any appropriate combination and / or sub-combination in one or more embodiments or examples. In addition, those of ordinary skill in the art should understand that the drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0046] In the description of the present invention, the orientation or positional relationship indicated by terms such as "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the protection scope of the present invention.

[0047] Embodiment 1

[0048] When detecting a circuit breaker traditionally, people usually pay more attention to the mechanical state of the circuit breaker and ignore the harm caused by the insulation defect of the circuit breaker. Especially in the closing resistor, if its insulation defect is not detected, when the closing resistor generates insulation discharge or breakdown, serious accidents are likely to occur.

[0049] This embodiment discloses a method for identifying the state of a closing resistor. By real-time monitoring the current mutation data of the fault recording data and converting it into a resistance value curve for comparison with the rated resistance value curve, the state of the closing resistor is judged, realizing the real-time monitoring of the state of the closing resistor, and avoiding the occurrence of accidents such as insulation discharge or breakdown of the closing resistor. In this embodiment, the state of the closing resistor is judged by identifying the relevant data of the circuit breaker. The schematic diagram of the specific identification method is as Figure 1 shown, and the method steps include:

[0050] S1: Obtain fault recording data;

[0051] In step S1, the obtained fault recording data is the data sampled when the whole station recorder is started simultaneously for recording directly during the operation or fault of the substation, and the sampling frequency of the fault recording data is greater than or equal to 4 kHz.

[0052] S2: Extract the waveform segments of current mutation in the fault recording data to obtain several waveform segment data; the waveform segment data is the waveform data that starts timing when the current mutates and occurs within 30 ms after the delay.

[0053] In step S2, to realize the state monitoring of the closing resistor of the line switch circuit breaker QF1, the waveform starting from the instruction issued by QF1 as the starting time T1 is intercepted, and the time window is 30 ms. Here, the starting time is the moment when the current mutates, and the time window refers to the waveform situation that occurs within 30 ms after starting timing from the mutation. If a waveform involves multiple operations of QF1, the waveforms corresponding to multiple operation times T2, T3... are intercepted respectively. Therefore, in a piece of obtained data, there may be multiple current mutation data, and the following steps are needed to judge the mutation data.

[0054] S3: Select any waveform segment data, and calculate the corresponding resistance curve in the waveform segment data, traverse several waveform segment data, and obtain several resistance curves;

[0055] The specific calculation sub-steps of the resistance curve include:

[0056] In the waveform segment data, the voltage and current of each data point are obtained; the resistance of the data point is calculated based on the obtained voltage and current, and after each data point is calculated, the resistance values ​​corresponding to several data points are obtained; and according to the time sequence of the occurrence of the data points, the several resistance values ​​are connected to obtain a resistance curve.

[0057] In the waveform segment data, the method for obtaining the voltage is:

[0058] Acquire a first voltage on the waveform segment data line and a second voltage on an adjacent line;

[0059] The first voltage and the second voltage are differentially calculated to obtain the voltage. In the acquired waveform segment data, the voltage U1 and current I1 of the circuit breaker QF1 corresponding to each data point are obtained. The current of QF1 is the current of QF1 passing through the line monitored by the fault recorder; the voltage of QF1 needs to be obtained with the help of the line voltage U l1 and adjacent lines U ln The voltage of this line U l1 and adjacent lines U ln Difference U l1 -U ln By performing a vector subtraction operation on the waveform, the voltage U1 obtained is the voltage across the circuit breaker QF1.

[0060] The resistance curve of the closing resistor is obtained. The resistance curve here is obtained by calculating the data of each sampled point. The waveform U1 / I1 is calculated point by point, that is, the value of the closing resistor R1 at each point is obtained. The resistance value of each point can be connected to form a resistance curve. The change of the curve can be intuitively compared: the closing resistor is put into operation a few milliseconds before the main break (arc extinguishing chamber) is closed, and it is automatically cut off a few milliseconds after the main break is closed. After the circuit breaker issues the QF1 operation command, the closing resistor is put into operation from the current mutation, and is short-circuited and exited when the main contact is closed. Generally, the closing resistor input lasts for about 10ms.

[0061] S4: Compare the resistance curves with the rated closing resistance resistance curves to obtain the closing resistance state. The closing resistance state is determined as follows: when the closing resistance drops suddenly in the resistance value of the input device, the closing resistance state is defective.

[0062] Specific implementation process:

[0063] As Figure 2 shown, it is the closing resistor curves of phases B and C of the same line. The rated resistance is 400Ω. The closing resistor curve of phase C of Yueya Line 1 changes normally. The resistance of phase B of Yueya Line 1 drops below 300Ω within 0.4ms after the closing resistor is put into operation, and then hovers between 300Ω and 400Ω within 3.6ms. After 3.6ms, the resistance continues to drop. From this, it can be judged that there is a defect in this kind of resistor, and a power outage test is required for maintenance.

[0064] A method for identifying the state of a closing resistor disclosed in this embodiment monitors the current mutation data of the fault recording data in real time, and converts it into a resistance value curve for comparison with the rated resistance value curve to judge the state of the closing resistor, realizing the process of real-time monitoring of the state of the closing resistor, and avoiding the occurrence of accidents such as insulation discharge or breakdown of the closing resistor.

[0065] Embodiment 2

[0066] This embodiment discloses a system for identifying the state of a closing resistor. This embodiment is to implement the identification method in Embodiment 1, including a data acquisition module, a waveform extraction module, a resistance value curve calculation module, and a state judgment module;

[0067] The data acquisition module is used to acquire fault recording data;

[0068] The waveform extraction module is used to extract the waveform segments of current mutation in the fault recording data to obtain several waveform segment data;

[0069] The resistance value curve calculation module is used to select any one of the waveform segment data and calculate the corresponding resistance value curve in this waveform segment data, and traverse several waveform segment data to obtain several resistance value curves;

[0070] The state judgment module is used to compare several of the resistance value curves with the rated closing resistor resistance value curve respectively to obtain the state of the closing resistor.

[0071] The resistance value curve calculation module includes a voltage and current acquisition module, a calculation module, and a connection module;

[0072] The voltage and current acquisition module is used to acquire the voltage and current of each data point in the waveform segment data;

[0073] The calculation module is used to calculate the resistance of this data point based on the obtained voltage and current. After each data point is calculated, the resistance values corresponding to several data points are obtained;

[0074] The connection module is used to connect several of the resistance values according to the time sequence of the occurrence of data points to obtain a resistance value curve.

[0075] The voltage and current acquisition module further includes a sub-voltage acquisition module and a difference operation module.

[0076] The sub-voltage acquisition module is used to acquire a first voltage on the waveform segment data line and a second voltage on an adjacent line.

[0077] The difference operation module is used to perform a difference operation on the first voltage and the second voltage to obtain the voltage, where the voltage is the voltage difference between the line where the switch is located and the adjacent line, the current is the current of this line, and the closing resistance value is voltage / current.

[0078] Embodiment III

[0079] This embodiment discloses a computer storage medium on which a computing program is stored. When the computer program is executed by a processor, the method described in Embodiment I is implemented.

[0080] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0081] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram can be implemented by computer program issued instructions, and the combination of the processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program issued instructions. These computer program issued instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the issued instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0082] These computer program issued instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the issued instructions stored in the computer-readable memory generate a manufactured product including the issued instruction device, and the issued instruction device implements the functions in the process Figure 1One or more processes and / or boxes Figure 1 The functions specified in one box or more boxes.

[0083] These computer program issuing instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the issuing instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one process Figure 1 One or more processes and / or boxes Figure 1 The steps of the functions specified in one box or more boxes.

[0084] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for identifying the state of a closing resistor, characterized in that, The method steps include: Obtain fault recording data; Extract the waveform segments with current mutations from the fault recording data to obtain several waveform segment data; Select any one of the waveform segment data and calculate the corresponding resistance curve in this waveform segment data. Traverse several waveform segment data to obtain several resistance curves; Compare several of the resistance curves with the rated closing resistor resistance curve respectively to obtain the closing resistor state; The specific calculation sub-steps of the resistance curve include: in the waveform segment data, obtain the voltage and current of each data point; calculate the resistance of this data point based on the obtained voltage and current. After calculating each data point, obtain the resistance values corresponding to several data points; then connect several of the resistance values according to the time sequence of the occurrence of the data points to obtain the resistance curve; In the waveform segment data, the method for obtaining the voltage is: obtain the first voltage on the waveform segment data line and the second voltage on the adjacent line; perform a difference operation on the first voltage and the second voltage to obtain the voltage; The discrimination of the closing resistor state is: when the mutation of the resistance value drop occurs in the closing resistor during the device input, the state of this closing resistor is defective.

2. The method for identifying the state of a closing resistor according to claim 1, characterized in that, The sampling frequency of the fault recording data is greater than or equal to 4 kHz.

3. The method for identifying the state of a closing resistor according to claim 1, characterized in that, The waveform segment data is the waveform data that starts timing when the current mutates and occurs within 30 ms later.

4. A system for identifying the state of a closing resistor, characterized in that, It includes a data acquisition module, a waveform extraction module, a resistance curve calculation module, and a state judgment module; The data acquisition module is used to obtain fault recording data; The waveform extraction module is used to extract the waveform segments with current mutations from the fault recording data to obtain several waveform segment data; The resistance curve calculation module is used to select any one of the waveform segment data and calculate the corresponding resistance curve in this waveform segment data. Traverse several waveform segment data to obtain several resistance curves; The state judgment module is used to compare several of the resistance curves with the rated closing resistor resistance curve respectively to obtain the closing resistor state; The discrimination of the closing resistor state is: when the mutation of the resistance value drop occurs in the closing resistor during the device input, the state of this closing resistor is defective; The resistance curve calculation module includes a voltage and current acquisition module, a calculation module, and a connection module; the voltage and current acquisition module is used to obtain the voltage and current of each data point in the waveform segment data; the calculation module is used to calculate the resistance of this data point based on the obtained voltage and current. After calculating each data point, obtain the resistance values corresponding to several data points; The connection module is used to connect several of the resistance values according to the time sequence of the occurrence of the data points to obtain the resistance curve; The voltage and current acquisition module further includes a sub-voltage acquisition module and a difference operation module. The sub-voltage acquisition module is used to obtain the first voltage on the waveform segment data line and the second voltage on the adjacent line; the difference operation module is used to perform a difference operation on the first voltage and the second voltage to obtain the voltage.

5. A computer storage medium, on which a computer program is stored, characterized in that, When the computer program is executed by a processor, it implements the recognition method as described in any one of claims 1 to 3.

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