CN114895180A - Electric service life analysis technology of direct current breaker - Google Patents
Electric service life analysis technology of direct current breaker Download PDFInfo
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- CN114895180A CN114895180A CN202210747393.7A CN202210747393A CN114895180A CN 114895180 A CN114895180 A CN 114895180A CN 202210747393 A CN202210747393 A CN 202210747393A CN 114895180 A CN114895180 A CN 114895180A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
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- G06F17/18—Complex mathematical operations for evaluating statistical data, e.g. average values, frequency distributions, probability functions, regression analysis
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- G—PHYSICS
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- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
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- G—PHYSICS
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- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/04—Ageing analysis or optimisation against ageing
Abstract
The invention discloses a direct current breaker electrical life analysis technology, which uses a calculation and estimation algorithm to calculate the maximum value I of short-circuit current (di/dt (max) x1/2T + I (max)) according to collected data, input data and judgment data, and calculates the maximum allowable cut-off times of any cut-off short-circuit current by adopting an approximate proportion according to the experimental data given by a product; the method adopts a percentage method to unify the influence of different on-off currents and times on the electric service life of the circuit breaker so as to obtain the service life of the circuit breaker; the invention calculates the residual life, finds the time when the residual life reaches the lowest limit in time, and overhauls or replaces the equipment, thereby reducing the accident rate, reducing the loss and improving the reliability of the equipment.
Description
Technical Field
The invention relates to the field of urban rail transit direct-current traction power supply systems, in particular to a direct-current breaker electric service life analysis technology.
Background
A direct-current switch cabinet in a direct-current traction power supply system of urban rail transit is important electrical equipment in a traction substation, and in the long-term operation process of the equipment, the service life of a circuit breaker, which is the most important component in the switch cabinet, influences the maintenance period of the whole equipment operation. In recent years, the rapid development of urban rail transit industry in China brings great challenges to the operation and maintenance capacity of urban rail companies. Because the actual state visibility of equipment is low, the health state is unclear, the breaking current of the circuit breaker is different every time, the loss of corresponding circuit breaker contacts and arc extinguish chambers is different, the service life of the whole circuit breaker is affected differently, the electrical service life of the circuit breaker cannot be reliably judged only by artificial experience and capability, and therefore a technical means is needed to be used for accurate data acquisition, calculation and analysis.
In order to solve the above problems, for example, chinese patent publication No. CN114626312A discloses a method for comprehensively evaluating the electrical life of a circuit breaker, which specifically comprises the following steps: step 1: establishing a magnetohydrodynamic simulation model according to a designed arc extinguish chamber structure of the circuit breaker; step 2: the time-space evolution characteristics of the electric arc under different voltages and different current magnitudes, the electric arc current, the electric arc voltage and the passing energy are obtained through simulation calculation, and a database of circuit breaker simulation results is established; and step 3: calculating the electrical life of the new circuit breaker product: and calculating the residual electric life of the circuit breaker operating on line. Therefore, comprehensive evaluation of the electric service lives of different circuit breakers is realized. The invention theoretically evaluates the electric service life parameters of a new circuit breaker product, can evaluate the number of the residual electric service life according to the real-time state of the circuit breaker, saves the cost and improves the accuracy of the electric service life evaluation. The method can be applied to low-voltage circuit breakers, but also to high-voltage gas circuit breakers.
Also, for example, chinese patent publication No. CN112084662A discloses a method and an apparatus for detecting the electrical life of a circuit breaker, specifically, receiving the type and the on-off state of the circuit breaker to be detected, which are input by a user; performing off-line dynamic resistance measurement on the circuit breaker to be detected to obtain the dynamic resistance at the point of the circuit breaker to be detected; comparing the dynamic resistance with an evaluation curve in a pre-established comparison database to obtain the reliability and the electric service life of the next cut-off of the circuit breaker; responding to a query request of a user, and outputting the model, related parameters, reliability and electric service life of the circuit breaker to be detected; and the obtained reliability and the electric service life are classified into a comparison database. Therefore, the electric service life of the circuit breaker can be calculated only by measuring the dynamic resistance without adopting a large number of tests, so that the detection efficiency is improved, the reliability can be obtained, and the detection effect is improved.
At present, the existing circuit breaker electric service life analysis technology has the following defects: the first patent establishes a magnetohydrodynamics simulation model, establishes a database of circuit breaker simulation results through simulation calculation, and calculates the residual electric life of the circuit breaker operating on line. The second patent derives the electrical life of the circuit breaker by measuring the dynamic resistance and comparing the measured values with a pre-established comparison database. Both patents are realized by establishing a database, the scheme is relatively complex, the cost is high, the accuracy needs to be improved, and the prior art still needs to be improved.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a technology for analyzing the electric service life of a direct current breaker, which aims to solve the problems.
In order to achieve the purpose, the invention is realized by the following technical scheme:
a technology for analyzing the electric service life of a direct current breaker comprises the following steps:
s1, acquiring collected data: by adopting a calculation estimation method, necessary acquisition data is provided for a circuit breaker electric service life analysis device by utilizing a protection device of the existing direct-current switch cabinet without adding extra measurement equipment;
s2 calculates the trip current and input data: the breaker electric service life analysis device calculates the short-circuit on-off current by using data provided by a protection device of the direct-current switch cabinet, which is the difficulty of the whole data calculation analysis and is used as the measurement data for judging the electric service life, namely the input data;
s3 acquiring judgment data: inputting the electrical service life characteristic parameters of the circuit breaker which leaves the factory into an electrical service life analysis device of the circuit breaker to serve as reference data for electrical service life judgment, namely judgment data;
s4 calculates the remaining electrical life: the used electrical service life and the residual electrical service life of the circuit breaker are obtained by analyzing the collected data, the input data and the judgment data, and the method is subdivided into the following steps:
firstly, a protection device measures, records and provides;
② calculating the cut-off current
Opening times N corresponding to the opening current;
fourthly, the electrical service life value S of this time Book (I) 1/(the number of times of disconnection corresponding to the disconnection current);
used electrical life value S Has already been used for The electric service life value S Book (I) + last used electrical life value S On the upper part (initial value is 0);
total electrical life value S General assembly Value of used electrical life S Has already been used for + residual electrical life value S The residue is left 。
Further, in the step S1, in acquiring the collected data, the dc switch cabinets are all provided with a protection device to collect corresponding current and voltage data on the dc traction power supply system in real time, that is, the current and voltage data corresponding to the dc circuit breaker.
Further, in the step S1, the main current data in the collected data is stored and calculated in real time by a device specially used for analyzing the electric life of the circuit breaker.
Further, in step S2, when the short-circuit breaking current is calculated from the calculated short-circuit breaking current and the input data, and the short-circuit breaking current is calculated within the measurable recording maximum value, the recording maximum value may be directly used as the maximum short-circuit current.
Further, step S2 calculates the short-circuit breaking current and the input data, calculates the recording maximum value duration when the short-circuit current exceeds the maximum value of the data record in calculating the short-circuit breaking current, screens out the maximum current change rate, and calculates the maximum value of the short-circuit current.
Further, in step S2, the short-circuit breaking current and the input data are calculated, and the maximum short-circuit current value formula is I ═ di/dt (max) x1/2T + I (max) by data estimation.
Further, in the step S3, in the judgment data, the electric life test data in the type test report of the circuit breaker directly adopts the electric life data of the circuit breaker, that is, the service life of the product.
Further, in step S4, in calculating the remaining electrical life, different on-off currents and on-off times are converted into a uniform electrical life percentage in a percentage manner.
Further, in step S4, the calculated percentage of the input data is used as the used electrical life, the test data is used as the judgment data, and the result of subtracting the input data is the remaining electrical life.
Further, step S4 is to calculate the remaining electrical life by subtracting the percentage of the used life from the 100% electrical life of the new product by a direct difference method to obtain the remaining percentage of the life.
Further, the step S4 is a subdivision step of calculating the remaining electrical life: the protection device measures, records and provides: maximum value of rate of change of current di/dt (max), duration T, maximum current of protection device
The value I (max);
calculating the on-off current:
the breaking current I is less than or equal to the maximum current value I (max) of the protection device, and the breaking current value I is equal to the current value I (max) of the protection device;
namely: i ═ I (max); - (formula 1)
The cut-off current value I > the maximum protection device current value I (max), the cut-off current value I ═ the maximum current change rate di/dt (max) x1/2x duration T + the maximum protection device current value I (max);
namely: i ═ di/dt (max) x1/2T + I (max) - (equation 2)
Thirdly, the breaking times N corresponding to the breaking current are based on the characteristic curve of the circuit breaker or test report data; e.g. 90kA switching current, corresponding to the number of switching-on/off times N 90 (ii) a But the characteristic curve or the test report data do not directly list the corresponding data, and approximate proportion calculation can be adopted;
fourthly, the electrical service life value S of this time Book (I) 1/(the number of times of disconnection corresponding to the disconnection current);
namely: s Book (I) 1/N; - (formula 3)
Used electrical life value S Has already been used for The electric service life value S Book (I) + last used electrical life value S On the upper part (initial value is 0);
S has already been used for ＝S Book (I) +S On the upper part - (formula 4)
Total electrical life value S General assembly Value of used electrical life S Has already been used for + residual electrical life value S The residue is left
The electric life value is counted by percentage, and the total electric life value S General assembly ＝1
S General assembly ＝S Has already been used for +S The residue is left - (equation 5).
Compared with the prior art, the device has the advantages that: a direct current breaker electric life analysis technology uses a calculation and estimation algorithm, calculates the maximum value I of short circuit current (di/dt (max) x1/2T + I (max)) according to collected data, input data and judgment data, and calculates the maximum allowable cut-off times of any cut-off short circuit current by adopting an approximate proportion according to experimental data given by a product; the method is characterized in that the percentage method is adopted, the influence of different on-off currents and times on the electric service life of the circuit breaker is unified, and the service life of the circuit breaker is obtained by combining the formula 1-the formula 5; the invention calculates the residual life, finds the time when the residual life reaches the lowest limit in time, and overhauls or replaces the equipment, thereby reducing the accident rate, reducing the loss and improving the reliability of the equipment.
Drawings
FIG. 1 is a schematic structural diagram of an electrical life analysis technique for a DC circuit breaker according to the present invention;
fig. 2 is a data acquisition diagram of a protection device for analyzing the electrical life of a dc circuit breaker according to the present invention (data cannot be read and recorded as a maximum value);
fig. 3 is a data diagram collected by the protection device of the dc circuit breaker electrical life analysis technique of the present invention (calculating the maximum current value that cannot be read);
FIG. 4 is a graph of current change rate data obtained from data provided by a protection device for a DC circuit breaker electrical life analysis technique in accordance with the present invention;
fig. 5 is a circuit breaker characteristic curve diagram according to the dc circuit breaker electrical life analysis technique of the present invention, and the electrical life operation times corresponding to different cut-off currents are used as the judgment basis.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
The invention provides a technical scheme that:
s1, acquiring collected data: the method adopts a calculation estimation method, does not need to add extra measuring equipment, mainly utilizes the protection device of the existing direct-current switch cabinet to provide necessary acquisition data for the circuit breaker electric service life analysis device, and generally, the direct-current switch cabinet is provided with one protection device to acquire corresponding current and voltage data on a direct-current traction power supply system in real time, namely the current and voltage data corresponding to the direct-current circuit breaker. The main current data is specially used for real-time storage and calculation of the breaker electric service life analysis device. The method comprises the following steps:
s2 calculates the trip current and input data: in an urban rail transit direct current traction power supply system, general short circuit on-off current is more than ten thousand amperes, data recorded by a protection device is only about 10000A-20000A, and calculation of the short circuit on-off current comprises two conditions: when the short-circuit current is within the measurable recording maximum value, the recording maximum value can be directly adopted as the maximum short-circuit current; when the short-circuit current exceeds the maximum value of the data record, calculating the duration of the maximum value record, screening out the maximum current change rate, and calculating the maximum value of the short-circuit current. The circuit breaker electric service life analysis device calculates the short-circuit on-off current by utilizing data provided by the protection device of the direct-current switch cabinet, which is the difficulty of the whole data calculation analysis and is used as the measurement data for judging the electric service life, namely the input data.
S3 calculates judgment data: inputting the electrical service life characteristic parameters of the circuit breaker which leaves the factory into an electrical service life analysis device of the circuit breaker to serve as reference data for electrical service life judgment, namely judgment data;
s4 calculates the remaining electrical life: the used electrical service life and the residual electrical service life of the circuit breaker are obtained by analyzing the collected data, the input data and the judgment data, and the method is subdivided into the following steps:
the protection device measures, records and provides: maximum value of rate of change of current di/dt (max), duration T, maximum current value of protection device i (max): as shown in fig. 2 and 4, di/dt (max) 548A/ms, T6 ms, i (max) 11000A;
calculating the on-off current:
the breaking current I is less than or equal to the maximum current value I (max) of the protection device, and the breaking current value I is equal to the current value I (max) of the protection device;
namely: i ═ I (max); - (equation 1)
The switching current value I > maximum protection device current value I (max), the switching current value I ═ maximum current rate of change di/dt (max) x1/2x duration T + maximum protection device current value I (max),
namely: i ═ di/dt (max) x1/2T + I (max) - (equation 2), I > I (max) as shown in fig. 2, and the above values are substituted into equation 2;
i ═ di/dt (max) x1/2T + I (max) 548x1/2x6+11000 ═ 12644a ═ 12.644kA, as shown in the peak values in fig. 3;
thirdly, the breaking times N corresponding to the breaking current are based on the characteristic curve of the circuit breaker or test report data; e.g. 90kA switching current, corresponding to the number of switching-on/off times N 90 (ii) a However, the characteristic curve or the test report data do not directly indicate the corresponding data, and approximate proportion calculation can be adopted, such as 10kA shown in FIG. 5<I<18kA, calculating the number of times of disconnection N in the current time to be 300-1000 by approximate proportion calculation, wherein (18-12.644)/(N-300) is (12.644-10)/(1000-N), and N is 769 times;
fourthly, the electrical service life value S of this time Book (I) 1/(the number of times of disconnection corresponding to the disconnection current),
namely: s Book (I) 1/N; - (equation 3), e.g., substituting N ═ 769 times into equation 3, S Book (I) ＝1/769＝0.13％；
Used electrical life value S Has already been used for The electric service life value S Book (I) + last used electricLife value S On the upper part (the initial value is 0) of the initial value,
S has already been used for ＝S Book (I) +S On the upper part - (equation 4), e.g. mixing S Book (I) Substituting 0.13% into equation 4, S Has already been used for ＝0.13％；
Total electrical life value S General assembly Value of used electrical life S Has already been used for + residual electrical life value S The residue is left ，
The electric life value is counted by percentage, and the total electric life value S General assembly ＝1，
S General assembly ＝S Has already been used for +S The residue is left - (equation 5), e.g. mixing S Has already been used for Substituting 0.13% into equation 5, S General assembly ＝S Has already been used for +S The residue is left ，S The residue is left ＝1-0.13％＝99.87％。
Test data for electrical life in type test report for circuit breakers: the electric life test of the circuit breaker is a damage test to the circuit breaker, so the various machine test is impossible, otherwise the reduction of the service life of the circuit breaker is accelerated, even if the tests are carried out, the electric life result of each circuit breaker is almost the same due to the production process and other reasons. Usually, the experimental data of the direct current circuit breaker are all from the most authoritative experimental organization in the world, and the standard of the experiment is generally the European standard or the latest national standard.
The frequency of different on-off short circuit currents which can be borne by the circuit breaker is different, so that the circuit breaker needs to be converted into consistent data for visual quantification, and therefore, a percentage mode is adopted, namely different on-off currents and the on-off frequency are converted into a unified electrical service life percentage. And taking the calculated percentage of the input data as the used electrical life, taking the tested data as the judgment data, and subtracting the result of the input data to obtain the residual electrical life. The specific working principle is as follows:
collecting data of a protection device of the direct-current switch cabinet: after the data collected by the protection device reaches the full-scale maximum value, the data is continuously recorded by the maximum value, as shown in fig. 2.
Calculation of short circuit breaking current: taking the maximum value recorded by the protection device as 11000A (the maximum value is set according to different items), when the short-circuit current is lower than 11000A, directly reading the maximum current value, and directly adopting the maximum value recorded as the maximum short-circuit current; when the short-circuit current is larger than 11000A, the corresponding maximum current value cannot be read, and the curve part above the rectangular area in FIG. 3 is the part which cannot be read, and needs to be calculated according to the waveform record of the protection device, namely screening the data provided by the protection device, selecting the maximum value of the current change rate di/dt, as shown in FIG. 4, calculating the maximum record current duration T, and calculating the maximum value of the short-circuit current: i ═ di/dt (max) x1/2T + I (max). Fig. 3 shows that the remaining part after the peak is removed is the actual recorded value, the part of the curve above the rectangular area is the estimated value, and the peak is the maximum value of the short-circuit current, in this process, the current is a half-up and half-down change process, and the duration is 31-25 to 6ms, that is, the time from the recorded maximum value to the short-circuit maximum value is about 1/2, that is, 3 ms; the maximum value di/dt (max) of the current change rate, i.e., 548kA/S or 548A/ms, is screened out from fig. 4, and the maximum recording current duration T is shown in fig. 3, which can also be obtained from the waveform recording data shown in fig. 4, where T is 31-25-6 ms; i (max) is the maximum value of fig. 3 from which the peak is removed, and can be obtained from the waveform recording data as shown in fig. 4, I (max) is 11000A, and I is the maximum value of the peak in fig. 3, that is, the calculated short-circuit current, the maximum value of the short-circuit current I is 548x6x1/2+11000A is 12644 a.
Test data for electrical life in type test report for circuit breakers: the number of times of opening and closing of the circuit breaker delivery characteristic parameter 90kA is 20 times, the number of times of opening and closing is 40 times at 50kA, the number of times of opening and closing is 300 times at 18kA, and the number of times of opening and closing is 1000 times at 10kA (and below). The data are parameters of the factory characteristics of the circuit breaker, and the service life is obtained without repeated verification through laboratory tests and years of verification of similar products on site. By adopting the above calculation, the maximum short-circuit current I is 12644a, i.e. 12.644kA, 10kA < I <18kA, the number of times n of disconnection at this time is 300-1000 times, and the approximate ratio is used to calculate (18-12.644)/(n-300) ═ (12.644-10)/(1000-n), so that n is 769 times.
Because the short-circuit current generated each time is different, the influence on the direct-current circuit breaker is different, namely the response to the electric service life is different, and the data needs to be converted into unified and visualized quantitative data, the percentage is adopted, for example, when the short-circuit current is 18kA, the used electric service life percentage is 1/300, namely 0.3%, the short-circuit current is generated for 90kA again, the used electric service life percentage is 1/20+ 0.3%, namely 5.3%, and the residual electric service life percentage is 100% -5.3% — 94.7%; the percentage of the short circuit current affecting the electrical lifetime calculated above is 1/769, i.e. 1.3%, and if 18kA and 90kA short circuit currents had occurred once before, the cumulative percentage of electrical lifetime used is 5.3% + 1.3% + 6.6%, and the remaining electrical lifetime percentage is 93.4%. And when the percentage of the residual electrical service life of the circuit breaker reaches the minimum limit of the actual service life of the product (the service life marked on the service specification when the product leaves the factory), overhauling or replacement is carried out in time.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (10)
1. A technology for analyzing the electric service life of a direct current breaker is characterized by comprising the following steps:
s1, acquiring collected data: the method comprises the steps that a calculation estimation method is adopted, and necessary collected data are provided for a circuit breaker electric service life analysis device by utilizing a protection device of an existing direct-current switch cabinet;
s2 calculates the short circuit break current and input data: by utilizing data provided by a protection device of the direct-current switch cabinet, the breaker electrical service life analysis device calculates the short-circuit breaking current as measurement data for judging the electrical service life, namely input data;
s3 acquiring judgment data: inputting the electrical service life characteristic parameters of the circuit breaker which leaves the factory into an electrical service life analysis device of the circuit breaker to serve as reference data for electrical service life judgment, namely judgment data;
s4 calculates the remaining electrical life: the used electrical service life and the residual electrical service life of the circuit breaker are obtained by analyzing the collected data, the input data and the judgment data, and the method is subdivided into the following steps:
firstly, a protection device measures, records and provides;
calculating the on-off current;
opening times N corresponding to the opening current;
fourthly, the electrical service life value S of this time Book (I) 1/(the number of times of disconnection corresponding to the disconnection current);
used electrical life value S Has already been used for The electric service life value S Book (I) + last used electrical life value S On the upper part (initial value is 0);
total electrical life value S General assembly Used electrical life value S Has already been used for + residual electrical life value S The residue is left 。
2. The electric life analysis technology of the direct current breaker according to claim 1, characterized in that: in the step S1, in acquiring the collected data, the dc switch cabinets are all provided with a protection device to collect the corresponding current and voltage data on the dc traction power supply system in real time, that is, the current and voltage data corresponding to the dc circuit breaker.
3. The electric life analysis technique of the direct current breaker according to claim 2, characterized in that: in the step S1, the main current data is stored and calculated in real time by a device dedicated to analyzing the electrical life of the circuit breaker, among the acquired data.
4. The electric life analysis technique of the direct current breaker according to claim 3, characterized in that: in the step S2 of calculating the short-circuit breaking current and inputting data, when the short-circuit breaking current is calculated, the maximum value may be directly recorded as the maximum short-circuit current when the short-circuit current is within the measurable recording maximum value.
5. The electric life analysis technology of the direct current breaker according to claim 4, characterized in that: step S2 calculates the maximum value of the recorded duration, screens out the maximum current change rate, and calculates the maximum value of the short-circuit current when the short-circuit current exceeds the maximum value of the data record in calculating the short-circuit off-current and inputting the data.
6. The electric life analysis technology of the direct current breaker according to claim 5, characterized in that: in step S2, the short-circuit breaking current and the input data are calculated, and the maximum short-circuit current value formula is I ═ di/dt (max) x1/2T + I (max) by data estimation.
7. The electric life analysis technology of the direct current breaker according to claim 6, characterized in that: in the step S3, in the judgment data, the electric life test data in the type test report of the circuit breaker directly adopts the electric life data of the circuit breaker, that is, the service life of the product.
8. The electric life analysis technique of the direct current breaker according to claim 7, characterized in that: step S4 converts the different on-off currents and on-off times into a uniform percentage of electrical life in calculating the remaining electrical life in a percentage manner.
9. The electric life analysis technique of the direct current breaker according to claim 8, characterized in that: step S4 is to calculate the remaining electrical life by subtracting the percentage of the used electrical life from the calculated percentage of the input data, the remaining electrical life from the result of subtracting the input data from the test data, and the percentage of the remaining electrical life from the 100% electrical life of the product by a direct difference method.
10. The electric life analysis technique of the direct current breaker according to claim 9, characterized in that:
the protection device measures, records and provides: maximum value of rate of change of current di/dt (max), duration T, maximum value of current of protection device i (max);
calculating the on-off current:
the breaking current I is less than or equal to the maximum current value I (max) of the protection device, and the breaking current value I is equal to the current value I (max) of the protection device;
namely: i ═ I (max); - (formula 1)
The switching current value I > maximum protection device current value I (max), the switching current value I ═ maximum current rate of change di/dt (max) x1/2x duration T + maximum protection device current value I (max),
namely: i ═ di/dt (max) x1/2T + I (max) - (equation 2);
thirdly, the breaking times N corresponding to the breaking current are based on the characteristic curve of the circuit breaker or test report data; e.g. 90kA switching current, corresponding to the number of switching-on/off times N 90 (ii) a But the characteristic curve or the test report data do not directly list the corresponding data, and approximate proportion calculation can be adopted;
fourthly, the electrical service life value S of this time Book (I) 1/(the number of times of disconnection corresponding to the disconnection current),
namely: s Book (I) 1/N; - (formula 3);
used electrical life value S Has already been used for The electric service life value S Book (I) + last used electrical life value S On the upper part (the initial value is 0) of the initial value,
S has already been used for ＝S Book (I) +S On the upper part - (formula 4);
total electrical life value S General assembly Value of used electrical life S Has already been used for + residual electrical life value S The residue is left
The electric life value is counted by percentage, and the total electric life value S General assembly ＝1
S General assembly ＝S Has already been used for +S The residue is left - (equation 5).
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116908674A (en) * | 2023-09-12 | 2023-10-20 | 川开电气有限公司 | Method and system for monitoring and predicting residual life of circuit breaker |
| CN116908674B (en) * | 2023-09-12 | 2023-11-28 | 川开电气有限公司 | Method and system for monitoring and predicting residual life of circuit breaker |
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