Method for evaluating residual electrical life of high-voltage circuit breaker based on multiple factors

Abstract

The invention relates to the field of circuit breakers, in particular to a multi-factor-based high-voltage circuit breaker residual electrical life evaluation method, which comprises the following steps of: calculating a multi-factor-based high-voltage circuit breaker current bearing capacity index; constructing a parameter time sequence; calculating an influence factor of the relevant parameters at the current moment on the relevant parameters at the next moment; predicting numerical values of relevant parameters at the next moment; calculating a current bearing capacity index at the next moment; and evaluating the residual electrical life state of the high-voltage circuit breaker. The method has the advantages that five key dynamic parameters including the bearing current of the high-voltage circuit breaker, the temperature of an arc extinguish chamber, the spring pressure of an operating mechanism, the action times of the operating mechanism and the vibration amplitude of a circuit breaker body are comprehensively considered, and the parameters jointly reflect the running state of the circuit breaker from multiple dimensions such as electricity, thermodynamics, mechanical stress and accumulated abrasion; and a multi-factor evaluation model closer to an actual working condition is established, so that the accuracy and reliability of residual electrical life evaluation are greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of circuit breakers, in particular to a multi-factor-based residual electrical life evaluation method for high-voltage circuit breakers. BACKGROUND

[0002] High-voltage circuit breakers are crucial control and protection devices in power systems, and their reliability is directly related to the safe and stable operation of the power grid. The electrical life of a circuit breaker refers to the number of times or the time that it can normally complete the breaking task under specified conditions, and is a key indicator for evaluating its performance state. With the deepening of the concept of power equipment condition-based maintenance, accurate evaluation of the residual electrical life of high-voltage circuit breakers has become a core technical requirement for realizing their predictive maintenance.

[0003] Currently, related technical research on the electrical life evaluation of high-voltage circuit breakers can be mainly divided into two categories: one is a single-data-based evaluation method, and the other is a data model-driven prediction method.

[0004] The single-data-based evaluation method usually takes the rated short-circuit current breaking times or the rated current breaking times of the circuit breaker as the criterion for electrical life. Although this method is simple and intuitive, it ignores the complexity and diversity of the operating conditions of the circuit breaker in actual operation. The power grid environment, load conditions, and operation frequency of each circuit breaker are different, and it is difficult to accurately reflect the true wear state and residual life of the circuit breaker based on fixed breaking times, so the evaluation results are often not accurate and have poor universality.

[0005] The data model-driven electrical life prediction method attempts to combine multiple measurement data for comprehensive evaluation by introducing fuzzy theory, establishing a degradation model, or applying artificial intelligence algorithms. This method to some extent overcomes the influence of subjective factors and improves the scientificity of the evaluation. However, its successful application is heavily dependent on a large amount of complete historical operating data, especially the measured data of key dynamic parameters such as arc burning time and contact travel curve. In actual engineering, it is already difficult to obtain a large number of sample data of the same type of circuit breaker under similar operating conditions, and it is even more difficult to obtain complete data of different types of circuit breakers under different operating conditions. Therefore, this method is limited by the lack of measured data, and its effectiveness and universality are severely challenged in actual application, especially in data acquisition difficult field environments.

[0006] In summary, the existing technology has the following main deficiencies: 1. Single evaluation factor: Multiple dynamic parameters (such as carrying current, arc chamber temperature, mechanism pressure, vibration, etc.) that affect the electrical life of the circuit breaker are not comprehensively considered, resulting in a disconnect between the evaluation model and the actual situation; 2. High data dependency: Model-driven methods require a large amount of homogeneous historical data, which is difficult to meet in actual engineering, thus limiting their widespread application. 3. Poor dynamic adaptability: Existing methods are difficult to effectively adapt to and characterize the dynamic changes of various parameters of circuit breakers in actual operation, and cannot achieve real-time and accurate assessment of remaining life. Summary of the Invention

[0007] The purpose of this invention is to provide a multi-factor-based method for assessing the remaining electrical life of high-voltage circuit breakers, which can achieve a more accurate, reliable, and engineering-practical assessment of the remaining electrical life under operating conditions with dynamic changes in multiple factors.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A multi-factor-based method for assessing the remaining electrical life of high-voltage circuit breakers includes: S1. Calculate the current carrying capacity index of high-voltage circuit breakers based on multiple factors. and based on the index The composition of the index is used to obtain the set of relevant parameters required to influence the index. High-voltage circuit breaker current carrying capacity index based on multiple factors The calculation formula is: ①; In formula ①: for A fixed time interval, where For natural numbers, , For the first At that moment, and For natural numbers, ; for Per-unit value of the circuit breaker's current carrying capacity measurement; for Per-unit value of the temperature measurement in the arc-extinguishing chamber of the circuit breaker at any given time; for Per-unit value of the spring pressure measurement of the operating mechanism at all times; for Per-unit value of the measurement of the number of times the operating mechanism moves; for Per-unit value of the measured vibration amplitude of the circuit breaker body at any given moment; S2. Measure relevant parameters and construct parameter time series based on the measured values; S3, calculate the influence factor of the current time related parameter on the next time related parameter ; S4, predict the value of the next time related parameter based on the parameter time series and the influence factor S5, calculate the current carrying capacity index of the next time with the normalized value of the predicted parameter ; S6, evaluate the residual electrical life state of the high voltage circuit breaker according to the capacity index

[0009] The parameter time series calculation formula is constructed as: ②.

[0010] The influence factor of the current time related parameter on the next time related parameter The calculation formula is: ③; In formula ③: is the fixed time interval, where is a natural number, , is the time, and is a natural number, ; is the circuit breaker carrying current measurement value at the time; is the circuit breaker arc chamber temperature measurement value at the time; is the operating mechanism spring pressure measurement value at the time; is the operating mechanism action frequency measurement value at the time; is the circuit breaker body vibration amplitude measurement value at the time.

[0011] Predict the value of the next time related parameter based on the parameter time series and the influence factor, the calculation formula is: ④; In formula ④: is the predicted value of the circuit breaker carrying current at the time; ​for Predicted value of the arc-extinguishing chamber temperature of the circuit breaker at any given time; for Predicted value of spring pressure of the operating mechanism at all times; for The predicted number of times the operating mechanism will move; for Predicted value of the vibration amplitude of the circuit breaker body at any given time.

[0012] Calculate the current carrying capacity index at the next time step using the normalized values ​​of the prediction parameters. The calculation formula is: ⑤.

[0013] According to the ability index Assess the remaining electrical life status of high-voltage circuit breakers, including: if If the circuit breaker has a high remaining electrical life, then it is determined that the high-voltage circuit breaker does not need to be tested. if If this occurs, it is determined that the remaining electrical life of the high-voltage circuit breaker has severely degraded, and the high-voltage circuit breaker needs to be inspected twice a month. if If this happens, the high-voltage circuit breaker is deemed to have completely failed its remaining electrical life and needs to be replaced.

[0014] Among them, let for At a fixed time interval The average value is .

[0015] The relevant parameter set includes the high-voltage circuit breaker's carrying current, the high-voltage circuit breaker's arc-extinguishing chamber temperature, the high-voltage circuit breaker's operating mechanism spring pressure and the number of operating mechanism actions, and the high-voltage circuit breaker's body vibration amplitude.

[0016] A multi-factor-based residual electrical life assessment system for high-voltage circuit breakers includes a data acquisition module, a data processing module, a prediction module, and an output module. The data acquisition module is used to measure the current carrying capacity of the high-voltage circuit breaker, the temperature of the arc-extinguishing chamber of the high-voltage circuit breaker, the spring pressure of the operating mechanism of the high-voltage circuit breaker and the number of times the operating mechanism is activated, and the vibration amplitude of the high-voltage circuit breaker body, and convert them into per-unit values. The data processing module is used to construct parameter time series and calculate impact factors; The prediction module is used to calculate the current carrying capacity index at the next moment using the normalized value of the prediction parameters. The output module is used to calculate based on the capability index. The residual electric life state of a high-voltage circuit breaker is evaluated.

[0017] Compared with the prior art, the present application has the following beneficial effects: 1. The present application breaks through the limitations of traditional single opening frequency or single parameter evaluation, and creatively comprehensively considers five key dynamic parameters of the high-voltage circuit breaker, i.e., current carrying capacity, temperature of the arc extinguishing chamber, spring pressure of the operating mechanism, operating frequency of the operating mechanism, and vibration amplitude of the circuit breaker body. These parameters jointly reflect the operating state of the circuit breaker from multiple dimensions, such as electricity, thermodynamics, mechanical stress, and cumulative wear, thereby establishing a multi-factor evaluation model closer to the actual working condition, and greatly improving the accuracy and reliability of the residual electric life evaluation. 2. By constructing a parameter time series and calculating an influence factor, the evolution trend of the key parameter at the next moment can be accurately predicted based on the historical and current data, and the current carrying capacity index at the future moment can be further predicted. This dynamic prediction capability enables the operation and maintenance personnel to perceive the risk before the performance of the circuit breaker significantly deteriorates or a fault occurs, thereby changing passive maintenance to active early warning and realizing truly predictive maintenance. 3. The present application does not rely on a large amount of historical operating data of the same type and working condition of the circuit breaker. Instead, it analyzes the real-time monitoring data sequence of the circuit breaker itself to establish a prediction model, effectively overcoming the difficulty that the model cannot be applied due to insufficient on-site data. The present application is suitable for high-voltage circuit breakers of different types and working conditions, and has good engineering applicability and promotional value. 4. The predicted current carrying capacity index is compared with the preset threshold (α, β), and three explicit operation levels, i.e., “no detection”, “monthly detection twice”, and “replacement required”, are given. This provides intuitive and quantitative operation basis for the on-site operation and maintenance personnel, avoids the randomness and uncertainty of experience-based judgment, and helps to develop a scientific and economic maintenance strategy and optimize resource allocation. 5. From data acquisition, modeling, prediction to state evaluation and operation decision, an automatic dynamic closed-loop process is formed, which can continuously operate and track the changes of the state of the circuit breaker in real time, ensuring that the evaluation results always reflect the latest status, and ensuring the safe and stable operation of the power grid. 6. The defined index formula and the mathematical form of the prediction model are simple, have clear physical meaning, and have small calculation amount. No complex algorithm and powerful computing power are required, and the present application is easy to integrate and deploy in the existing substation monitoring system or embedded device, and has high engineering practical value. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a multi-factor residual electric life evaluation process of a high-voltage circuit breaker. DETAILED DESCRIPTION

[0019] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0020] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0021] Example 1 See Figure 1 A multi-factor method for assessing the remaining electrical life of high-voltage circuit breakers is analyzed, taking the LW10B-252 type high-voltage SF6 circuit breaker, widely used in a 220kV substation of a certain city's power grid, as an example. The analysis includes: Step S1: Calculate the current carrying capacity index of high-voltage circuit breakers based on multiple factors. and based on the index The composition of the index is determined by obtaining the set of relevant parameters required for the index. The set of relevant parameters includes the high-voltage circuit breaker carrying current, the high-voltage circuit breaker arc-extinguishing chamber temperature, the high-voltage circuit breaker operating mechanism spring pressure and the number of operating mechanism actions, and the high-voltage circuit breaker body vibration amplitude. High-voltage circuit breaker current carrying capacity index based on multiple factors The calculation formula is: ①; In formula ①: for A fixed time interval, where For natural numbers, , For the first At that moment, and For natural numbers, ; for The per-unit value of the circuit breaker's current carrying capacity measurement is 4000A. If the current of phase A is consistently high on a certain day and the measured value is 4350A, the per-unit value is 1.0875. for The per-unit value of the measured temperature of the arc-extinguishing chamber of the circuit breaker. The upper limit of the permissible sound in the arc-extinguishing chamber is 65K, and the reference temperature is 30℃. If the measured value is 89℃, the per-unit value is 0.908. for The per-unit value of the spring pressure measurement of the operating mechanism is always specified. The base value is 25000N. If the measured value is 38500N, the per-unit value is 1.54. for The per-unit value of the measurement of the number of times the operating mechanism moves is 2000 times. If the measurement value is 4000 times, the per-unit value is 2. for The per-unit value of the vibration amplitude measurement of the circuit breaker body is expressed as acceleration (g). The base value is 300g. If the measured value is 750g, the per-unit value is 2.5.

[0022] Step S2: Measure the relevant parameters required for the multi-factor-based high-voltage circuit breaker current carrying capacity index, and establish a time series of the relevant parameters required for the multi-factor-based high-voltage circuit breaker current carrying capacity index based on the obtained measurement values. The formula for constructing the time series parameters is as follows: ②; (Select 4 consecutive hours) Then the relevant parameter time series is .

[0023] Step S3: Calculate the influence factors of the relevant parameters required for the multi-factor-based high-voltage circuit breaker current carrying capacity index on the relevant parameters required for the multi-factor-based high-voltage circuit breaker current carrying capacity index at the next moment. ， The calculation formula is: ③; In formula ③: for A fixed time interval, where For natural numbers, , For the first At that moment, and For natural numbers, ; for Per-unit value of the circuit breaker's current carrying capacity measurement; for Per-unit value of the temperature measurement in the arc-extinguishing chamber of the circuit breaker at any given time; for Per-unit value of the spring pressure measurement of the operating mechanism at all times; for Per-unit value of the measurement of the number of times the operating mechanism moves; for The per-unit value of the vibration amplitude measurement of the circuit breaker body at any given time.

[0024] Step S4: Based on the time series of relevant parameters required for the multi-factor-based high-voltage circuit breaker current carrying capacity index and the influence factors of the relevant parameters required for the multi-factor-based high-voltage circuit breaker current carrying capacity index on the relevant parameters required for the next time step, calculate... The predicted values ​​of the relevant parameters required for the multi-factor-based current carrying capacity index of high-voltage circuit breakers at any given time are calculated using the following formula: ④; In formula ④: for The predicted value of the current carried by the circuit breaker at any given time; for Predicted value of the arc-extinguishing chamber temperature of the circuit breaker at any given time; for Predicted value of spring pressure of the operating mechanism at all times; for The predicted number of times the operating mechanism will move; for Predicted value of the vibration amplitude of the circuit breaker body at any given time.

[0025] calculate The predicted values ​​of the relevant parameters required for the multi-factor-based current carrying capacity index of high-voltage circuit breakers at any given time are: .

[0026] Step S5: Calculate the normalized value of the predicted relevant parameters required for the multi-factor-based high-voltage circuit breaker current carrying capacity index. Predicted value of current carrying capacity index of high voltage circuit breaker based on multiple factors at any time. This enables the prediction of the current carrying capacity index of high-voltage circuit breakers based on multiple factors. The calculation formula is as follows: ⑤; Based on the above data, the calculation is as follows: The calculation yields: ; If this happens, the remaining electrical life of the high-voltage circuit breaker will be severely degraded in the next moment, requiring the high-voltage circuit breaker to be inspected twice a month.

[0027] Step S6: Based on the ability index The remaining electrical life status of high-voltage circuit breakers is assessed.

[0028] The probability index of sudden changes in the wear degree of high-voltage circuit breaker contacts, based on big data monitoring, reflects the characteristic relationship of five variables: circuit breaker contact temperature rise, contact resistance, circuit breaker body vibration frequency, circuit breaker breaking current, and circuit breaker breaking frequency. The faster the circuit breaker contact temperature rises, the greater the contact resistance, and the greater the sum of these two resistances compared to the sum of the parameters in the denominator. This indicates a higher probability index of sudden changes in the wear degree of high-voltage circuit breaker contacts, suggesting severe contact erosion and requiring timely inspection and preparation for circuit breaker replacement. This includes: if If the circuit breaker has a high remaining electrical life, then it is determined that the high-voltage circuit breaker does not need to be tested. if If this occurs, it is determined that the remaining electrical life of the high-voltage circuit breaker has severely degraded, and the high-voltage circuit breaker needs to be inspected twice a month. if If this happens, the high-voltage circuit breaker is deemed to have completely failed its remaining electrical life and needs to be replaced.

[0029] Among them, let for At a fixed time interval The average value is .

[0030] A multi-factor-based residual electrical life assessment system for high-voltage circuit breakers includes a data acquisition module, a data processing module, a prediction module, and an output module. The data acquisition module is used to measure the carrying current of the high-voltage circuit breaker, the temperature of the arc-extinguishing chamber of the high-voltage circuit breaker, the spring pressure of the operating mechanism of the high-voltage circuit breaker and the number of operating mechanism actions, and the vibration amplitude of the high-voltage circuit breaker body, and convert them into per-unit values. The data processing module is used to construct parameter time series and calculate impact factors; The prediction module is used to calculate the current carrying capacity index at the next moment using the normalized value of the prediction parameters. The output module is used to calculate based on the capability index. The remaining electrical life status of high-voltage circuit breakers is assessed.

[0031] This invention breaks through the limitations of traditional single-break count or single-parameter evaluation. It creatively integrates five key dynamic parameters of the high-voltage circuit breaker: current carrying capacity, arc-extinguishing chamber temperature, operating mechanism spring pressure, operating mechanism actuation count, and circuit breaker body vibration amplitude. These parameters reflect the circuit breaker's operating status from multiple dimensions, including electrical, thermodynamic, mechanical stress, and cumulative wear. This establishes a multi-factor evaluation model that more closely reflects actual operating conditions, significantly improving the accuracy and reliability of remaining electrical life assessment. By constructing parameter time series and calculating influencing factors, it can accurately predict the evolution trend of key parameters at the next moment based on historical and current data, thereby predicting the current carrying capacity index at future moments. This dynamic prediction capability allows maintenance personnel to detect risks before significant performance degradation or failure occurs, transforming passive maintenance into proactive early warning, achieving true predictive maintenance. It does not rely on a large amount of historical operating data from circuit breakers of the same model and operating conditions; instead, it establishes a predictive model by analyzing the real-time monitoring data sequence of the circuit breaker itself, effectively overcoming… Addressing the challenge of limited on-site data hindering model application, this invention is applicable to different types and operating conditions of high-voltage circuit breakers, demonstrating excellent engineering applicability and widespread value. By comparing the predicted current carrying capacity index with preset thresholds (α, β), it provides three clear maintenance levels: "no inspection required," "inspect twice a month," and "replacement required." This offers on-site maintenance personnel intuitive and quantifiable operational guidance, avoiding the arbitrariness and uncertainty of experience-based judgments. It facilitates the development of scientific and economical maintenance strategies and optimizes resource allocation. From data acquisition, modeling, and prediction to status assessment and maintenance decision-making, an automated, dynamic closed-loop process is formed. This process can continuously operate, tracking changes in circuit breaker status in real time, ensuring that assessment results always reflect the latest situation and guaranteeing the safe and stable operation of the power grid. The defined index formula and prediction model have a simple mathematical form, clear physical meaning, and low computational load. They do not require complex algorithms or powerful computing capabilities, making them easy to integrate and deploy in existing substation monitoring systems or embedded devices, thus possessing high engineering practical value.

Claims

1. A multi-factor-based method for assessing the remaining electrical life of high-voltage circuit breakers, characterized in that, include: S1. Calculate the current carrying capacity index of high-voltage circuit breakers based on multiple factors. and based on the index The composition of the index is used to obtain the set of relevant parameters required to influence the index. High-voltage circuit breaker current carrying capacity index based on multiple factors The calculation formula is: ①； In formula ①: for A fixed time interval, where For natural numbers, , For the first At that moment, and For natural numbers, ; for Per-unit value of the circuit breaker's current carrying capacity measurement; for Per-unit value of the temperature measurement in the arc-extinguishing chamber of the circuit breaker at any given time; for Per-unit value of the spring pressure measurement of the operating mechanism at all times; for Per-unit value of the measurement of the number of times the operating mechanism moves; for Per-unit value of the measured vibration amplitude of the circuit breaker body at any given moment; S2. Measure relevant parameters and construct parameter time series based on the measured values; S3. Calculate the influence factors of the relevant parameters at the current time on the relevant parameters at the next time. ; S4. Predict the values ​​of relevant parameters at the next time step based on parameter time series and impact factors; S5. Calculate the current carrying capacity index at the next moment using the normalized value of the prediction parameters. ; S6. Based on the ability index The remaining electrical life status of high-voltage circuit breakers is assessed.

2. The method for assessing the remaining electrical life of high-voltage circuit breakers based on multiple factors according to claim 1, characterized in that, The formula for calculating the time series of the construction parameters is as follows: ②。 3. The method for assessing the remaining electrical life of high-voltage circuit breakers based on multiple factors according to claim 1, characterized in that, The influence factor of the relevant parameters at the current time on the relevant parameters at the next time. The calculation formula is: ③； In formula ③: for A fixed time interval, where For natural numbers, , For the first At that moment, and For natural numbers, ; for Per-unit value of the circuit breaker's current carrying capacity measurement; for Per-unit value of the temperature measurement in the arc-extinguishing chamber of the circuit breaker at any given time; for Per-unit value of the spring pressure measurement of the operating mechanism at all times; for Per-unit value of the measurement of the number of times the operating mechanism moves; for The per-unit value of the vibration amplitude measurement of the circuit breaker body at any given time.

4. The method for assessing the remaining electrical life of high-voltage circuit breakers based on multiple factors according to claim 1, characterized in that, The formula for predicting the values ​​of relevant parameters at the next time step based on parameter time series and influence factors is as follows: ④； In formula ④: for The predicted value of the current carried by the circuit breaker at any given time; for Predicted value of the arc-extinguishing chamber temperature of the circuit breaker at any given time; for Predicted value of spring pressure of the operating mechanism at all times; for The predicted number of times the operating mechanism will move; for Predicted value of the vibration amplitude of the circuit breaker body at any given time.

5. The method for assessing the remaining electrical life of high-voltage circuit breakers based on multiple factors according to claim 1, characterized in that, The method described above uses the normalized values ​​of the prediction parameters to calculate the current carrying capacity index for the next time step. The calculation formula is: ⑤。 6. The method for predicting sudden changes in the wear degree of high-voltage circuit breaker contacts based on big data analysis according to claim 1, characterized in that, The aforementioned based on the ability index Assess the remaining electrical life status of high-voltage circuit breakers, including: if If the circuit breaker has a high remaining electrical life, then it is determined that the high-voltage circuit breaker does not need to be tested. if If this occurs, it is determined that the remaining electrical life of the high-voltage circuit breaker has severely degraded, and the high-voltage circuit breaker needs to be inspected twice a month. if If this happens, the remaining electrical life of the high-voltage circuit breaker is deemed to have completely failed, and the high-voltage circuit breaker needs to be replaced. Among them, let for At a fixed time interval The average value is .

7. The method for assessing the remaining electrical life of a high-voltage circuit breaker based on multiple factors according to claim 1, characterized in that, The relevant parameter set includes the high-voltage circuit breaker carrying current, the high-voltage circuit breaker arc-extinguishing chamber temperature, the high-voltage circuit breaker operating mechanism spring pressure and the number of operating mechanism actions, and the high-voltage circuit breaker body vibration amplitude.

8. A multi-factor-based residual electrical life assessment system for high-voltage circuit breakers, used to implement the method of any one of claims 1-7, characterized in that, It includes a data acquisition module, a data processing module, a prediction module, and an output module. The data acquisition module is used to measure the carrying current of the high-voltage circuit breaker, the temperature of the arc-extinguishing chamber of the high-voltage circuit breaker, the spring pressure of the operating mechanism of the high-voltage circuit breaker and the number of operating mechanism actions, and the vibration amplitude of the high-voltage circuit breaker body, and convert them into per-unit values. The data processing module is used to construct parameter time series and calculate impact factors; The prediction module is used to calculate the current carrying capacity index at the next moment using the normalized value of the prediction parameters. The output module is used to calculate based on the capability index. The remaining electrical life status of high-voltage circuit breakers is assessed.

Images