An on-line monitoring system and method for an open-type circuit breaker applying electric field intensity

Abstract

The present invention discloses an on-line monitoring system and method for an open-type circuit breaker applying electric field intensity in the technical field of on-line monitoring of open-type circuit breakers, including: extracting the electric field intensities at different positions of the ABC-phase circuit breaker; constructing an electric field intensity curve based on the extracted electric field intensities; determining whether the electric field intensity curve conforms to the characteristic curve law; when the electric field intensity curve does not conform to the characteristic curve law, determining that the circuit breaker has a fault and giving an alarm, otherwise determining that there is no fault. The present invention provides new parameters for the on-line monitoring system of the circuit breaker by extracting the distribution law of the electric field intensity of the open-type circuit breaker, improving the working efficiency and fault diagnosis rate of the on-line monitoring system of the open-type circuit breaker and the universality for different types of circuit breakers.

Description

Technical Field

[0001] The present invention relates to an on-line monitoring system and method for an open-type circuit breaker applying electric field intensity, belonging to the technical field of on-line monitoring of open-type circuit breakers. Background Art

[0002] A circuit breaker refers to a switching device that can close, carry, and interrupt the current under normal circuit conditions and can close, carry, and interrupt the current under abnormal circuit conditions within a specified time. Circuit breakers are classified into high-voltage circuit breakers and low-voltage circuit breakers according to their application scope. The boundary between high and low voltages is relatively blurred. Generally, electrical appliances above 3 kV are called high-voltage electrical appliances.

[0003] Due to the extensive use of circuit breakers in substations and their important functions of current on-off and fault removal, circuit breakers have become an important part of ensuring the safe and stable operation of the power grid. The popularization of intelligent substations highlights the importance of on-line monitoring technology. Accurate and rapid fault judgment is the core of the on-line monitoring system. Therefore, researching an on-line monitoring method for open-type circuit breakers applying electric field intensity as on-line monitoring is of great significance for improving the fault diagnosis category and diagnosis rate of the on-line monitoring system for open-type circuit breakers.

[0004] The current main index for on-line monitoring of open-type circuit breakers is vibration signals. However, traditional vibration signals cannot meet the requirements of on-line monitoring of circuit breakers in new-type intelligent substations. Currently, there is no better monitored quantity, and the current on-line monitoring parameters cannot meet the requirements of on-line monitoring of circuit breakers. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an on-line monitoring system and method for an open-type circuit breaker applying electric field intensity. By extracting the distribution law of the electric field intensity of the open-type circuit breaker, new parameters are provided for the on-line monitoring system of the circuit breaker, and the working efficiency and fault diagnosis rate of the on-line monitoring system for open-type circuit breakers and the universality for different types of circuit breakers are improved.

[0006] To achieve the above purpose, the present invention is implemented by the following technical solutions:

[0007] In the first aspect, the present invention provides an on-line monitoring method for an open-type circuit breaker applying electric field intensity, including:

[0008] Extracting the electric field intensity at different positions of the ABC-phase circuit breaker;

[0009] Constructing an electric field intensity curve based on the extracted electric field intensity;

[0010] Judging whether the electric field intensity curve conforms to the characteristic curve law;

[0011] When the electric field strength curve does not conform to the characteristic curve law, it is determined that the circuit breaker has a fault and an alarm is given; otherwise, it is determined that there is no fault.

[0012] Furthermore, the method for obtaining the characteristic curve law is as follows:

[0013] Equivalent the arc extinguishing chamber of the circuit breaker and construct a theoretical equivalent model of the circuit breaker;

[0014] Establish a space coordinate system for the theoretical equivalent model;

[0015] Apply the simulated charge method to solve the electric field in space of the theoretical equivalent model;

[0016] Fix the coordinates of the YZ, XZ, and XY axes respectively, analyze the variation trend of the electric field strength with the X, Y, and Z coordinates, and obtain the variation trend curve;

[0017] After verifying the variation trend curve, use it as the characteristic curve law.

[0018] Furthermore, equivalent the arc extinguishing chamber of the circuit breaker and construct a theoretical equivalent model of the circuit breaker, including: equivalent the arc extinguishing chamber part to a finite-length conductor with a phase current, and at the same time combine the incoming and outgoing line cables of the circuit breaker to construct a theoretical equivalent model of the circuit breaker.

[0019] Furthermore, verify the variation trend curve, including:

[0020] Establish an ANSYS electromagnetic field simulation model for circuit breakers of different models and different voltage levels;

[0021] Set the simulation materials according to the actual materials and set the voltage excitation according to the actual voltage level to obtain the simulation results;

[0022] Verify the consistency between the simulation results and the variation trend curve;

[0023] When the simulation results are consistent with the variation trend curve, conduct on-site measurement tests for verification.

[0024] Furthermore, set the simulation materials according to the actual materials, including: set the porcelain sleeve and connection part of the circuit breaker as porcelain materials, set the conductor as aluminum according to the actual steel-core aluminum stranded wire, and set other metal structures as stainless steel.

[0025] Furthermore, the on-site measurement test verification includes:

[0026] Conduct on-site measurement tests at the same positions as those of the theoretical and simulated circuit breakers of the same model;

[0027] Obtain the on-site measurement variation trend with the X coordinate at different test positions for circuit breakers of different models;

[0028] Verify the consistency between the on-site measurement variation trend and the variation trend curve;

[0029] When the measured change trend is consistent with the change trend curve, the change trend curve is determined as the characteristic curve law.

[0030] Furthermore, the characteristic curve law is that the electric field strength shows an "M"-shaped characteristic curve of increasing first, then decreasing, then increasing again, and then decreasing again as the X coordinate increases.

[0031] In a second aspect, the present invention provides an on-line monitoring system for an open-type circuit breaker applying electric field strength, including:

[0032] An extraction module: used to extract the electric field strength at different positions of the ABC-phase circuit breaker;

[0033] A curve construction module: used to construct an electric field strength curve based on the extracted electric field strength;

[0034] A judgment module: used to judge whether the electric field strength curve conforms to the characteristic curve law;

[0035] An alarm module: used to determine that the circuit breaker has a fault and alarm when the electric field strength curve does not conform to the characteristic curve law, otherwise determine that there is no fault.

[0036] In a third aspect, the present invention provides an on-line monitoring device for an open-type circuit breaker applying electric field strength, including a processor and a storage medium;

[0037] The storage medium is used to store instructions;

[0038] The processor is used to operate according to the instructions to execute the steps of the method.

[0039] In a fourth aspect, the present invention provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the method are implemented.

[0040] Compared with the prior art, the beneficial effects achieved by the present invention:

[0041] Aiming at the deficiencies of the existing on-line monitoring methods for circuit breakers, through theoretical, simulation, and measured analysis of the distribution characteristics of the electric field strength around the circuit breaker, the general distribution law of the electric field strength of the open-type circuit breaker is summarized, providing a new on-line monitoring and fault diagnosis method for the circuit breaker. Compared with the traditional on-line monitoring device for open-type circuit breakers, this method extracts the distribution law of the electric field strength of the open-type circuit breaker, provides new parameters for the on-line monitoring system of the circuit breaker, improves the working efficiency and fault diagnosis rate of the on-line monitoring system of the open-type circuit breaker and its versatility for different types of circuit breakers, ultimately improves the safety factor of the open-type circuit breaker, ensures the safe and reliable operation of the power system, can reduce the consumption of manpower and material resources, and improves the stability and reliability of the circuit breaker and even the power grid. Brief Description of the Drawings

[0042] Figure 1 is the closing state diagram of the circuit breaker provided in the first embodiment of the present invention;

[0043] Figure 2 is the single-phase equivalent model diagram of the circuit breaker provided in the first embodiment of the present invention;

[0044] Figure 3 is the three-phase circuit breaker equivalent model diagram provided in the first embodiment of the present invention;

[0045] Figure 4 is the circuit breaker coordinate definition diagram provided in the first embodiment of the present invention;

[0046] Figure 5 is the theoretical calculation result of the electric field strength distribution of the 220kV circuit breaker provided in the first embodiment of the present invention;

[0047] Figure 6 is the theoretical calculation result of the electric field strength distribution of the 35kV circuit breaker provided in the first embodiment of the present invention;

[0048] Figure 7 is the simulation model for calculating the electric field strength of the 220kV circuit breaker provided in the first embodiment of the present invention;

[0049] Figure 8 is the simulation model for calculating the electric field strength of the 35kV circuit breaker provided in the first embodiment of the present invention;

[0050] Figure 9 is the simulation calculation result of the electric field strength distribution of the 220kV circuit breaker provided in the first embodiment of the present invention;

[0051] Figure 10 is the simulation calculation result of the electric field strength distribution of the 35kV circuit breaker provided in the first embodiment of the present invention;

[0052] Figure 11 is the physical diagram of the 220kV circuit breaker provided in the first embodiment of the present invention;

[0053] Figure 12 is the physical diagram of the 35kV circuit breaker provided in the first embodiment of the present invention;

[0054] Figure 13 is the measured result of the electric field strength distribution of the 220kV circuit breaker provided in the first embodiment of the present invention;

[0055] Figure 14 is the measured result of the electric field strength distribution of the 35kV circuit breaker provided in the first embodiment of the present invention;

[0056] Figure 15 is the flow chart of the on-line monitoring system for the electric field strength of the circuit breaker provided in the first embodiment of the present invention. Detailed implementation manners

[0057] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0058] Embodiment 1:

[0059] This embodiment proposes an on-line monitoring method for an open-type circuit breaker applying electric field intensity, and the technical solution adopted is as follows:

[0060] I. Theoretical modeling analysis of the electric field intensity of the open-type circuit breaker

[0061] Most of the open-type circuit breakers in the 500 kV substation are porcelain post circuit breakers, and the subsequent circuit breaker refers to the open-type circuit breaker. First, analyze the circuit equivalent structure of the porcelain post circuit breaker. The circuit breaker is composed of an incoming cable, an outgoing cable, and an arc extinguishing chamber. Analyze the closing state of the circuit breaker. As Figure 1 shown, the arc extinguishing chamber is equivalent. Through Figure 1 it can be known that when the circuit breaker is in the closing state, the static and dynamic main contacts responsible for current conduction are in contact with each other and are basically a straight line. Therefore, in theoretical calculations, the arc extinguishing chamber part is equivalent to a finite-length conductor for the phase current. At the same time, combined with the incoming and outgoing cables of the circuit breaker, the theoretical equivalent diagram of the single-phase circuit breaker as Figure 2 shown (the arrows in the figure represent the current flow direction) can be obtained. Combining the three-phase circuit breaker, the equivalent model of the circuit breaker can be obtained as Figure 3 .

[0062] Define the coordinate system of the circuit breaker as Figure 4 shown. The circuit breaker is distributed on the ground, the Z coordinate of the ground is 0, the XY coordinates of the B-phase circuit breaker are 0, and the coordinate origin is defined at the ground directly below the porcelain sleeve of the B-phase circuit breaker.

[0063] Apply the simulated charge method to solve Figure 3 the electric field of the equivalent model in space, fix the YZ, XZ, and XY axis coordinates respectively, and analyze the change trend of the electric field intensity with the X, Y, and Z coordinates.

[0064] It is found through research that the electric field intensity has no fixed law with the YZ coordinates. When the YZ is fixed, the change trend of the electric field intensity of the 220 kV circuit breaker with the X coordinate presents an "M" shape, as Figure 5 shown. Changing the voltage level, the change trend of the electric field intensity of the 35 kV circuit breaker with the X coordinate also presents an "M" shape, as Figure 6 shown. In addition, the X coordinates of the A and C phases correspond to the peak positions, and the X coordinate of the B phase corresponds to the trough position.

[0065] The YZ referred to is fixed, with the Z coordinate being 1.6 m and the Y coordinate being ±1 m. The Z coordinate is actually the height of the breaker crossbeam, and the selection of the YZ coordinates should conform to the actual situation.

[0066] The so-called "M" type specifically means that the electric field strength first increases, then decreases, then increases again, and then decreases again as the X coordinate increases.

[0067] II. Simulation Modeling Verification of the Electric Field Strength Law of Open-Type Circuit Breakers

[0068] ANSYS electromagnetic field simulation models of circuit breakers with different models and voltage levels are established, as Figures 7-8 shown.

[0069] Set the simulation materials according to the actual materials. Specifically, include: set the porcelain sleeve and connection part of the circuit breaker as porcelain material, set the wire as aluminum according to the actual ACSR, and set other metal structures as stainless steel. Set the voltage excitation according to the actual voltage level. The simulation results are as follows Figures 9-10 shown.

[0070] The simulation results can verify the theoretical analysis results. The variation trend of the electric field strength with the X coordinate shows an "M" type, and the positions of the peaks and valleys are also basically the same as those in the simulation. The difference is that the theoretical analysis shows that the electric field strength is symmetric about the X axis, and the electric field strength on the positive X half-axis is greater than that on the negative X half-axis. The reason is that the mechanism box is located on the positive X half-axis and has an impact on the electric field strength.

[0071] III. Field Measurement Verification of the Electric Field Strength Law of Open-Type Circuit Breakers

[0072] Field measurement tests are carried out at the same positions on the circuit breaker of the same model as the theory and simulation. The circuit breaker is as Figures 11-12 shown, and the field measurement results are as Figures 13-14 shown.

[0073] Through field measurement verification, the variation trend of circuit breakers of different models at different test positions with the X coordinate all shows an "M" type. The AC-phase circuit breaker is at the peak position, and the B-phase circuit breaker is at the valley position. This conclusion is universal for different models of open-type circuit breakers.

[0074] After confirming the conclusion of the "M" type characteristic curve of the electric field strength, the "M" type curve of the electric field strength under the normal working state of the circuit breaker can be monitored, and the electric field strengths at the corresponding positions of the ABC-phase circuit breakers can be extracted as monitoring sub-parameters. Once the electric field strength curve does not conform to the law of the "M" type curve, it can be determined that the circuit breaker has a fault, and the on-line monitoring device will alarm, thus effectively monitoring and diagnosing the faults of the circuit breaker.

[0075] The conclusion of the "M"-type curve of the electric field strength proposed in this paper can preferably use the on-line monitoring parameter of the electric field strength to monitor and fault diagnose the circuit breaker, and can provide new ideas and theoretical guidance for the on-line monitoring of the circuit breaker.

[0076] Embodiment 2:

[0077] An on-line monitoring system for an open-type circuit breaker applying the electric field strength, which can implement the on-line monitoring method for an open-type circuit breaker applying the electric field strength described in Embodiment 1, includes:

[0078] An extraction module: used for extracting the electric field strength at different positions of the ABC-phase circuit breaker;

[0079] A curve construction module: used for constructing an electric field strength curve based on the extracted electric field strength;

[0080] A judgment module: used for judging whether the electric field strength curve conforms to the characteristic curve rule;

[0081] An alarm module: used for determining that the circuit breaker has a fault and alarming when the electric field strength curve does not conform to the characteristic curve rule, otherwise determining that there is no fault.

[0082] Embodiment 3:

[0083] The embodiment of the present invention also provides an on-line monitoring device for an open-type circuit breaker applying the electric field strength, which can implement the on-line monitoring method for an open-type circuit breaker applying the electric field strength described in Embodiment 1, including a processor and a storage medium;

[0084] The storage medium is used for storing instructions;

[0085] The processor is used for operating according to the instructions to execute the steps of the following method:

[0086] Extracting the electric field strength at different positions of the ABC-phase circuit breaker;

[0087] Constructing an electric field strength curve based on the extracted electric field strength;

[0088] Judging whether the electric field strength curve conforms to the characteristic curve rule;

[0089] When the electric field strength curve does not conform to the characteristic curve rule, determining that the circuit breaker has a fault and alarming, otherwise determining that there is no fault.

[0090] Embodiment 4:

[0091] The embodiment of the present invention also provides a computer-readable storage medium, which can implement the on-line monitoring method for an open-type circuit breaker applying the electric field strength described in Embodiment 1, and a computer program is stored thereon, and when the program is executed by a processor, the steps of the following method are implemented:

[0092] Extract the electric field strengths at different positions of the ABC-phase circuit breaker;

[0093] Construct an electric field strength curve based on the extracted electric field strengths;

[0094] Determine whether the electric field strength curve conforms to the characteristic curve law;

[0095] When the electric field strength curve does not conform to the characteristic curve law, determine that the circuit breaker has a fault and give an alarm; otherwise, determine that there is no fault.

[0096] 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 take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take 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.

[0097] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (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 instructions, and the combination of processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program 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 instructions executed by the processor of the computer or other programmable data processing devices generate a device for realizing the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0098] These computer program 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 instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device realizes the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0099] These computer program 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 instructions executed on the computer or other programmable device provide for realizing the functions specified in one process Figure 1 one process or multiple processes and / or blocksFigure 1 Steps of functions specified in one or more boxes.

[0100] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An on-line monitoring method for an open-type circuit breaker applying electric field intensity, characterized in that, it includes: extracting the electric field intensities at different positions of the ABC-phase circuit breaker; constructing an electric field intensity curve based on the extracted electric field intensities; judging whether the electric field intensity curve conforms to the characteristic curve law; when the electric field intensity curve does not conform to the characteristic curve law, determining that the circuit breaker has a fault and giving an alarm, otherwise determining that there is no fault; wherein, the obtaining method of the characteristic curve law is: equivalent the arc extinguishing chamber of the circuit breaker and construct a theoretical equivalent model of the circuit breaker; establish a space coordinate system of the theoretical equivalent model; apply the simulated charge method to solve the electric field in space of the theoretical equivalent model; fix the YZ, XZ, and XY axis coordinates respectively, analyze the change trend of the electric field intensity with the X, Y, and Z coordinates, and obtain the change trend curve; after verifying the change trend curve, use it as the characteristic curve law.

2. The on-line monitoring method for an open-type circuit breaker applying electric field intensity according to claim 1, characterized in that, equivalent the arc extinguishing chamber of the circuit breaker and construct a theoretical equivalent model of the circuit breaker, including: equivalent the arc extinguishing chamber part to a finite-length conductor passing the phase current, and at the same time construct the theoretical equivalent model of the circuit breaker in combination with the incoming and outgoing line cables of the circuit breaker.

3. The on-line monitoring method for an open-type circuit breaker applying electric field intensity according to claim 1, characterized in that, verifying the change trend curve includes: establishing an ANSYS electromagnetic field simulation model for circuit breakers of different models and different voltage levels; setting the simulation materials according to the actual materials and setting the voltage excitation according to the actual voltage level to obtain the simulation results; verifying the consistency between the simulation results and the change trend curve; when the simulation results are consistent with the change trend curve, conduct on-site measurement tests for verification.

4. The on-line monitoring method for an open-type circuit breaker applying electric field intensity according to claim 3, characterized in that, setting the simulation materials according to the actual materials, including: setting the porcelain sleeve and connecting body parts of the circuit breaker as porcelain materials, setting the conductors as aluminum according to the actual steel-core aluminum stranded wire, and setting other metal structures as stainless steel.

5. The on-line monitoring method for an open-type circuit breaker applying electric field intensity according to claim 3, characterized in that, the on-site measurement test verification includes: conducting on-site measurement tests at the same positions as those of the theoretical and simulated circuit breakers of the same model; obtaining the on-site measurement change trend of different models of circuit breakers at different test positions with respect to the X coordinate; verifying the consistency between the on-site measurement change trend and the change trend curve; when the on-site measurement change trend is consistent with the change trend curve, determining the change trend curve as the characteristic curve law.

6. The on-line monitoring method for an open-type circuit breaker applying electric field intensity according to claim 1, characterized in that, the characteristic curve law is an "M"-type characteristic curve in which the electric field intensity first increases, then decreases, then increases, and then decreases as the X coordinate increases.

7. An on-line monitoring system for an open-type circuit breaker applying electric field intensity, characterized in that, it includes: an extraction module: used to extract the electric field intensities at different positions of the ABC-phase circuit breaker; a curve construction module: used to construct an electric field intensity curve based on the extracted electric field intensities; Judgment module: used to judge whether the electric field strength curve conforms to the characteristic curve law; Alarm module: used to determine that there is a fault in the circuit breaker and alarm when the electric field strength curve does not conform to the characteristic curve law, otherwise determine that there is no fault; The acquisition method of the characteristic curve law is as follows: Equivalent the arc extinguishing chamber of the circuit breaker to construct a theoretical equivalent model of the circuit breaker; Establish a space coordinate system for the theoretical equivalent model; Apply the simulated charge method to solve the electric field in space of the theoretical equivalent model; Fix the coordinates of the YZ, XZ, and XY axes respectively, analyze the change trend of the electric field strength with the X, Y, and Z coordinates, and obtain the change trend curve; After verifying the change trend curve, use it as the characteristic curve law.

8. An on-line monitoring device for an open-type circuit breaker applying electric field strength, Characterized in that, It includes a processor and a storage medium; The storage medium is used to store instructions; The processor is used to operate according to the instructions to execute the steps of the method according to claim 1.

9. A computer-readable storage medium, on which a computer program is stored, Characterized in that, When the program is executed by the processor, it implements the steps of the method according to claim 1.

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