Circuit breaker mechanical characteristics monitoring method and system based on air temperature changes during opening process

Abstract

The present invention provides a method and system for monitoring the mechanical characteristics of a circuit breaker based on air temperature changes during a circuit breaker opening process, comprising: obtaining a gas temperature rise change curve at a circuit breaker contact during the circuit breaker opening process; performing feature extraction on the obtained gas temperature rise change curve to obtain the arc extinguishing time of the circuit breaker; obtaining a gas temperature rise rate based on the obtained gas temperature rise change curve, and correcting the arc extinguishing time of the circuit breaker using the gas temperature rise rate to obtain the corrected arc extinguishing time of the circuit breaker; the present invention utilizes gas temperature change data caused by the action of the circuit breaker, and based on feature extraction of the gas temperature change data, can directly obtain the mechanical characteristic parameters of the arc extinguishing time, this process does not require excessive calculation processes, and corrects the arc extinguishing time of the circuit breaker using the gas temperature rise rate, thereby avoiding the influence of the load current size, improving the monitoring accuracy, and can provide accurate data for subsequent fault diagnosis, and provide an effective reference basis for later maintenance decisions.

Description

Technical Field

[0001] The present invention belongs to the technical field of circuit breaker monitoring, and in particular relates to a circuit breaker mechanical characteristic monitoring method and system based on air temperature changes during a circuit breaker opening process. Background Art

[0002] SF6 circuit breaker is a circuit breaker that uses SF6 gas as arc extinguishing and insulating medium. It has the advantages of strong breaking capacity, good breaking performance, long electrical life, good thermal stability, simple structure and maintenance. It is widely used in 35kV and above power systems. In order to improve the reliability of circuit breaker operation, necessary inspection and maintenance of the circuit breaker is required.

[0003] The inventors have found that in the existing SF6 high-voltage circuit breaker operating status assessment method, there is also a method of using gas thermometer pressure data to monitor the circuit breaker, but it requires a lot of calculation processes, the workload is large, and does not consider the impact of gas changes on the load current, resulting in low monitoring accuracy. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a method and system for monitoring the mechanical characteristics of a circuit breaker based on air temperature changes during the opening process. The present invention uses the SF6 gas temperature change data caused by the operation of the circuit breaker to directly obtain the mechanical characteristic parameters by extracting the characteristics of the temperature change data. The calculation amount is small, and the arc extinguishing time of the circuit breaker is corrected by the temperature rise rate of the SF6 gas, thereby avoiding the influence of the load current and improving the monitoring accuracy.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] In a first aspect, the present invention provides a method for monitoring mechanical characteristics of a circuit breaker based on air temperature changes during a circuit breaker opening process, comprising:

[0007] Obtain the gas temperature rise curve at the circuit breaker contacts during the opening process;

[0008] Perform feature extraction on the acquired gas temperature rise curve to obtain the arc extinguishing time of the circuit breaker;

[0009] The gas temperature rise rate is obtained according to the obtained gas temperature rise change curve, and the arc extinguishing time of the circuit breaker is corrected by using the gas temperature rise rate to obtain the corrected arc extinguishing time mechanical characteristic of the circuit breaker.

[0010] Furthermore, when performing feature extraction, the arc extinguishing time of the circuit breaker is equal to the difference between the time corresponding to when the gas temperature reaches the maximum value and the time corresponding to when the gas temperature begins to rise.

[0011] Furthermore, the time when the gas temperature reaches the maximum value corresponds to the time when the arc is last extinguished, and the time when the gas temperature begins to rise corresponds to the time when the arc burns for the first time.

[0012] Furthermore, when the arc extinguishing time of the circuit breaker is corrected using the gas temperature rise rate: the gas temperature rise change curve segment corresponding to the arc extinguishing time is divided into multiple segments according to the time average, the gas temperature rise rate in each segment is calculated, and the maximum gas temperature rise rate in all segments is determined; the preset reference gas temperature rise rate is divided by the maximum gas temperature rise rate as the correction value, and the corrected arc extinguishing time is equal to the product of the correction value and the uncorrected arc extinguishing time.

[0013] Furthermore, the preset reference gas temperature rise rate is selected from historical monitoring data.

[0014] Furthermore, when the arc extinguishing time of the circuit breaker is corrected by using the gas temperature rise rate: the gas temperature rise change curve segments corresponding to the arc extinguishing time of multiple monitored circuit breakers are divided into multiple segments according to the average time, the gas temperature rise rate in each segment is calculated, and the maximum gas temperature rise rate in all segments is determined to obtain the maximum gas temperature rise rate corresponding to each circuit breaker;

[0015] For any circuit breaker to be corrected, the maximum gas temperature rise rate of other circuit breakers divided by the maximum gas temperature rise rate of the circuit breaker to be corrected is used as the correction value. The corrected arc extinguishing time is equal to the product of the correction value and the uncorrected arc extinguishing time. The average value of all corrected arc extinguishing times is taken as the final arc extinguishing time.

[0016] Furthermore, for each circuit breaker, the maximum gas temperature rise rate of other circuit breakers is divided by the maximum gas temperature rise rate of the circuit breaker to be corrected as a correction value to obtain the corrected arc extinguishing time of all circuit breakers; the corrected arc extinguishing time of all circuit breakers is compared, and the circuit breaker with the largest difference is identified as the circuit breaker with the highest probability of failure.

[0017] In a second aspect, the present invention further provides a circuit breaker mechanical characteristic monitoring system based on air temperature changes during the opening process, comprising:

[0018] The data acquisition module is configured to: obtain a gas temperature rise curve at the circuit breaker contacts during the opening process;

[0019] The calculation module is configured to: extract features from the acquired gas temperature rise curve to obtain the arc extinguishing time of the circuit breaker;

[0020] The correction module is configured to obtain the gas temperature rise rate according to the obtained gas temperature rise change curve, and use the gas temperature rise rate to correct the arc extinguishing time of the circuit breaker to obtain the corrected arc extinguishing time mechanical characteristics of the circuit breaker.

[0021] In a third aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for monitoring mechanical characteristics of a circuit breaker based on changes in air temperature during a circuit breaker opening process as described in the first aspect.

[0022] In a fourth aspect, the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for monitoring mechanical characteristics of a circuit breaker based on changes in air temperature during a circuit breaker opening process as described in the first aspect are implemented.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention utilizes the gas temperature change data caused by the operation of the circuit breaker, and based on feature extraction of the gas temperature change data, the mechanical characteristic parameters of the arc extinguishing time can be directly obtained. This process does not require too many calculation processes, and the calculation workload is small. The arc extinguishing time of the circuit breaker is corrected by the gas temperature rise rate, which avoids the influence of the load current size and improves the monitoring accuracy. It can provide accurate data for subsequent fault diagnosis and provide an effective reference basis for later maintenance decisions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0026] Figure 1 is a method block diagram of Embodiment 1 of the present invention;

[0027] Figure 2 This is an example diagram of the SF6 gas temperature variation with time curve during the circuit breaker opening process of Example 1 of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0030] Embodiment 1:

[0031] The mechanical characteristic parameters of the high-voltage circuit breaker during the closing process include the closing stroke, closing time, closing speed, and closing coil current peak value. The mechanical characteristic parameters of the high-voltage circuit breaker during the opening process include the opening stroke, opening time, opening speed, and opening coil current peak value. Among them, the circuit breaker opening and closing time is a necessary condition to ensure that the circuit breaker can open (close) normally and reliably. The shorter the opening and closing time, the shorter the arc extinguishing time, the less the degree of contact burnout, and the longer the electrical life. The circuit breaker synchronization time is also to ensure the synchronous breaking of each phase and to extinguish the arc faster. The circuit breaker synchronization time can determine the phase-to-phase synchronization performance of the circuit breaker. Measuring the circuit breaker opening and closing time and synchronization can determine whether the circuit breaker can be put into operation normally.

[0032] The temperature change of SF6 gas caused by the opening and closing process of the circuit breaker can reflect the arc discharge process inside the circuit breaker. The temperature change of SF6 gas can be used to test the mechanical characteristics of the circuit breaker and provide auxiliary data for judging the circuit breaker fault.

[0033] like Figure 1 As shown in FIG. 1 , a circuit breaker mechanical characteristic monitoring method based on the temperature change during the opening process is provided.

[0034] include:

[0035] Obtain the gas temperature rise curve at the circuit breaker contacts during the opening process;

[0036] Perform feature extraction on the acquired gas temperature rise curve to obtain the arc extinguishing time of the circuit breaker;

[0037] The gas temperature rise rate is obtained according to the obtained gas temperature rise change curve, and the arc extinguishing time of the circuit breaker is corrected by using the gas temperature rise rate to obtain the corrected arc extinguishing time mechanical characteristic of the circuit breaker.

[0038] In this embodiment, the circuit breaker can be monitored online using a temperature sensor installed on the circuit breaker contacts to obtain the temperature rise of SF6 gas caused by the circuit breaker operation. After the data is collected and transmitted, the mechanical characteristic parameters are extracted to obtain the status parameters reflecting the health status of the circuit breaker, which can be used as the data basis for subsequent fault diagnosis, thereby providing a reference for maintenance decisions.

[0039] During the opening process of the circuit breaker, since the line current cannot change suddenly, plasma will be generated between the contacts to form an arc. The arc has a strong thermal effect and releases a large amount of heat, causing the temperature of the SF6 gas to rise. When the circuit breaker starts to open, an arc is formed, and the heat released causes the temperature of the SF6 gas to begin to rise; as the arc continues to burn, the temperature of the SF6 gas continues to rise until the arc is completely extinguished and the SF6 gas temperature reaches its maximum value; then as the heat is transferred to the outside, the temperature of the SF6 gas slowly decreases and tends to the normal temperature; during the opening process of the circuit breaker, the curve of the temperature change of the SF6 gas pressure over time is shown in the following example Figure 2 As shown. Among them, t1 is the time when the arc first burns, t m is the time when the arc is finally extinguished. m -t1 represents the mechanical characteristic of the arc extinguishing time of the circuit breaker. It can be understood that when performing feature extraction, the arc extinguishing time of the circuit breaker is equal to the difference between the corresponding time when the gas temperature reaches the maximum value and the corresponding time when the gas temperature begins to rise; the corresponding time when the gas temperature reaches the maximum value is the last time the arc is extinguished, and the corresponding time when the gas temperature begins to rise is the first time the arc burns.

[0040] In this embodiment, when the arc extinguishing time of the circuit breaker is corrected using the gas temperature rise rate: the gas temperature rise change curve segment corresponding to the arc extinguishing time is divided into multiple segments according to the time average, the gas temperature rise rate in each segment is calculated, and the maximum gas temperature rise rate in all segments is determined; the preset reference gas temperature rise rate is divided by the maximum gas temperature rise rate as the correction value, and the corrected arc extinguishing time is equal to the product of the correction value and the uncorrected arc extinguishing time; the preset reference gas temperature rise rate can be selected from the historical monitoring data.

[0041] Specifically, the larger the line load current, the more intense the arc is when opening, the harder it is to extinguish the arc, and the longer the arc extinguishing time is; in order to eliminate the influence of load current on arc extinguishing time in mechanical property evaluation, other variables need to be introduced for correction. The larger the line load current, the more intense the arc is when opening, and the greater the heat released per unit time, resulting in a faster temperature rise of SF6 gas. Therefore, the temperature rise rate of SF6 gas can be used to correct the arc extinguishing time of the circuit breaker, so as to achieve a comparison of the mechanical characteristics of the arc extinguishing time of the circuit breaker under different line currents, and then judge the quality and change trend of the mechanical characteristics of the circuit breaker.

[0042] In this embodiment, Figure 2 As shown, it can be m Select three time points t2, t3 and t4 with equal time interval Δt, calculate the temperature rise ΔT1, ΔT2, ΔT3 and ΔT4 corresponding to each time interval, and calculate the temperature rise speed a1, a2, a3 and a4;

[0043]

[0044] In order to fully consider the ablation damage of short-term severe arc to electric shock, the maximum value a among a1, a2, a3 and a4 is selected. max As a representation of the severity of the arc, the calculated mechanical characteristics of the arc extinguishing time of the circuit breaker are appropriately corrected; the preset value a 参照 Refers to the maximum temperature rise of the circuit breaker used as a reference, and the corrected arc extinguishing time is:

[0045]

[0046] This enables the comparison of mechanical characteristics of circuit breakers under different line currents; understandably, the preset value a 参照 It is the data processed and filtered out from the historical monitoring data.

[0047] Embodiment 2:

[0048] Different from Example 1, in this embodiment, when the arc extinguishing time of the circuit breaker is corrected by using the gas temperature rise rate: the gas temperature rise change curve segments corresponding to the arc extinguishing time of multiple monitored circuit breakers are divided into multiple segments according to the average time, the gas temperature rise rate in each segment is calculated, and the maximum gas temperature rise rate in all segments is determined to obtain the maximum gas temperature rise rate corresponding to each circuit breaker;

[0049] For any circuit breaker to be corrected, the maximum gas temperature rise rate of other circuit breakers divided by the maximum gas temperature rise rate of the circuit breaker to be corrected is used as the correction value. The corrected arc extinguishing time is equal to the product of the correction value and the uncorrected arc extinguishing time. The average value of all corrected arc extinguishing times is taken as the final arc extinguishing time.

[0050] For each circuit breaker, the maximum gas temperature rise rate of other circuit breakers is divided by the maximum gas temperature rise rate of the circuit breaker to be corrected as the correction value, and the corrected arc extinguishing time of all circuit breakers is obtained; the corrected arc extinguishing time of all circuit breakers is compared, and the circuit breaker with the largest difference is identified as the circuit breaker with the highest probability of failure.

[0051] This embodiment is applicable to the situation where multiple circuit breakers are monitored in real time without using historical data to judge the monitoring data. The monitoring data of multiple circuit breakers acquired in real time are used to correct each other, and the corrected arc extinguishing time mechanical characteristics are compared to achieve monitoring of the circuit breakers and preliminary estimation of the monitoring results.

[0052] Embodiment 3:

[0053] This embodiment provides a circuit breaker mechanical characteristic monitoring system based on air temperature changes during the opening process, including:

[0054] The data acquisition module is configured to: obtain a gas temperature rise curve at the circuit breaker contacts during the opening process;

[0055] The calculation module is configured to: extract features from the acquired gas temperature rise curve to obtain the arc extinguishing time of the circuit breaker;

[0056] The correction module is configured to obtain the gas temperature rise rate according to the obtained gas temperature rise change curve, and use the gas temperature rise rate to correct the arc extinguishing time of the circuit breaker to obtain the corrected arc extinguishing time mechanical characteristics of the circuit breaker.

[0057] The working method of the system is the same as the circuit breaker mechanical characteristic monitoring method based on the air temperature change during the opening process in Example 1, and will not be repeated here.

[0058] Embodiment 4:

[0059] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the steps of the method for monitoring mechanical characteristics of a circuit breaker based on air temperature changes during the opening process described in Embodiment 1 are implemented.

[0060] Embodiment 5:

[0061] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the method for monitoring mechanical characteristics of a circuit breaker based on air temperature changes during a circuit breaker opening process described in Example 1 are implemented.

[0062] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A circuit breaker mechanical characteristics monitoring method based on temperature changes during the opening process, characterized in that: include: Obtain the gas temperature rise curve at the circuit breaker contacts during the opening process; Perform feature extraction on the acquired gas temperature rise change curve to obtain the arc extinguishing time of the circuit breaker, wherein, when performing feature extraction, the arc extinguishing time of the circuit breaker is equal to the difference between the corresponding time when the gas temperature reaches the maximum value and the corresponding time when the gas temperature begins to rise, the corresponding time when the gas temperature reaches the maximum value is the last time the arc is extinguished, and the corresponding time when the gas temperature begins to rise is the first time the arc burns; According to the obtained gas temperature rise change curve, the gas temperature rise rate is obtained, and the gas temperature rise rate is used to correct the arc extinguishing time of the circuit breaker to obtain the corrected arc extinguishing time mechanical characteristics of the circuit breaker, wherein when the gas temperature rise rate is used to correct the arc extinguishing time of the circuit breaker: the gas temperature rise change curve segment corresponding to the arc extinguishing time is divided into multiple segments according to the time average, the gas temperature rise rate in each segment is calculated, and the maximum gas temperature rise rate in all segments is determined; the preset reference gas temperature rise rate is divided by the maximum gas temperature rise rate as the correction value, and the corrected arc extinguishing time is equal to the product of the correction value and the uncorrected arc extinguishing time.

2. The circuit breaker mechanical characteristics monitoring method based on air temperature changes during the opening process according to claim 1, characterized in that: The preset reference gas temperature rise rate is selected from historical monitoring data.

3. The circuit breaker mechanical characteristics monitoring method based on air temperature changes during the opening process according to claim 1, characterized in that: When the arc extinguishing time of the circuit breaker is corrected by using the gas temperature rise rate: the gas temperature rise change curve segments corresponding to the arc extinguishing time of multiple monitored circuit breakers are divided into multiple segments according to the average time, the gas temperature rise rate in each segment is calculated, and the maximum gas temperature rise rate in all segments is determined to obtain the maximum gas temperature rise rate corresponding to each circuit breaker; For any circuit breaker to be corrected, the maximum gas temperature rise rate of other circuit breakers divided by the maximum gas temperature rise rate of the circuit breaker to be corrected is used as the correction value. The corrected arc extinguishing time is equal to the product of the correction value and the uncorrected arc extinguishing time. The average value of all corrected arc extinguishing times is taken as the final arc extinguishing time.

4. The circuit breaker mechanical characteristics monitoring method based on air temperature changes during the opening process according to claim 3, characterized in that: For each circuit breaker, the maximum gas temperature rise rate of other circuit breakers is divided by the maximum gas temperature rise rate of the circuit breaker to be corrected as the correction value, and the corrected arc extinguishing time of all circuit breakers is obtained; the corrected arc extinguishing time of all circuit breakers is compared, and the circuit breaker with the largest difference is identified as the circuit breaker with the highest probability of failure.

5. A circuit breaker mechanical characteristic monitoring system based on temperature changes during the opening process, characterized in that: include: The data acquisition module is configured to: obtain a gas temperature rise curve at the circuit breaker contacts during the opening process; The calculation module is configured to: perform feature extraction on the acquired gas temperature rise change curve to obtain the arc extinguishing time of the circuit breaker, wherein when performing feature extraction, the arc extinguishing time of the circuit breaker is equal to the difference between the corresponding time when the gas temperature reaches the maximum value and the corresponding time when the gas temperature starts to rise, the corresponding time when the gas temperature reaches the maximum value is the last arc extinguishing time, and the corresponding time when the gas temperature starts to rise is the first arc burning time; The correction module is configured to: obtain the gas temperature rise rate based on the acquired gas temperature rise change curve, use the gas temperature rise rate to correct the arc extinguishing time of the circuit breaker, and obtain the corrected arc extinguishing time mechanical characteristics of the circuit breaker, wherein when the gas temperature rise rate is used to correct the arc extinguishing time of the circuit breaker: divide the gas temperature rise change curve segment corresponding to the arc extinguishing time into multiple segments according to the time average, calculate the gas temperature rise rate in each segment, and determine the maximum gas temperature rise rate in all segments; divide the preset reference gas temperature rise rate by the maximum gas temperature rise rate as the correction value, and the corrected arc extinguishing time is equal to the product of the correction value and the uncorrected arc extinguishing time.

6. The circuit breaker mechanical characteristic monitoring system based on air temperature changes during the opening process according to claim 5, characterized in that: The preset reference gas temperature rise rate is selected from historical monitoring data.

7. The circuit breaker mechanical characteristic monitoring system based on air temperature changes during the opening process according to claim 5, characterized in that: When the arc extinguishing time of the circuit breaker is corrected by using the gas temperature rise rate: the gas temperature rise change curve segments corresponding to the arc extinguishing time of multiple monitored circuit breakers are divided into multiple segments according to the average time, the gas temperature rise rate in each segment is calculated, and the maximum gas temperature rise rate in all segments is determined to obtain the maximum gas temperature rise rate corresponding to each circuit breaker; For any circuit breaker to be corrected, the maximum gas temperature rise rate of other circuit breakers divided by the maximum gas temperature rise rate of the circuit breaker to be corrected is used as the correction value. The corrected arc extinguishing time is equal to the product of the correction value and the uncorrected arc extinguishing time. The average value of all corrected arc extinguishing times is taken as the final arc extinguishing time.

8. The circuit breaker mechanical characteristic monitoring system based on air temperature changes during the opening process according to claim 7, characterized in that: For each circuit breaker, the maximum gas temperature rise rate of other circuit breakers is divided by the maximum gas temperature rise rate of the circuit breaker to be corrected as the correction value, and the corrected arc extinguishing time of all circuit breakers is obtained; the corrected arc extinguishing time of all circuit breakers is compared, and the circuit breaker with the largest difference is identified as the circuit breaker with the highest probability of failure.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method for monitoring mechanical characteristics of a circuit breaker based on air temperature changes during the opening process as described in any one of claims 1 to 4 are implemented.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method for monitoring mechanical characteristics of a circuit breaker based on air temperature changes during the opening process as described in any one of claims 1 to 4 are implemented.

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