A composite stress adaptive accelerated life test method and system of a mine vacuum contactor

Abstract

This invention relates to a method and system for adaptive accelerated life testing of a mining vacuum contactor under composite stress. The testing method includes: setting a composite stress spectrum based on the operating conditions of the mining vacuum contactor; the composite stress includes two or more of the following: vibration stress, impact stress, voltage fluctuation stress, load breaking stress, operating frequency stress, and environmental stress; applying composite stress to the mining vacuum contactor according to the composite stress spectrum; simultaneously acquiring multi-source test data of the mining vacuum contactor; extracting degradation characteristic quantities from the multi-source test data; calculating a comprehensive degradation index D and a current degradation rate r based on the degradation characteristic quantities; comparing the current degradation rate r with a preset target degradation rate range; if the current rate is less than or equal to a target degradation rate range, increasing the current stress level; if the current rate is less than or equal to a target degradation rate range, maintaining the current stress level; and if the current rate is less than or equal to a target degradation rate range, decreasing the current stress level. The testing method and system of this invention are more closely aligned with the actual conditions in coal mines, balancing experimental efficiency and realism.

Description

Technical Field

[0001] This invention relates to the field of life assessment technology for mining electrical equipment; specifically, this invention relates to a composite stress adaptive accelerated life test method and system for mining vacuum contactors. Background Technology

[0002] Mining vacuum contactors are widely used in the motor control circuits of coal mining equipment such as coal mining machines, scraper conveyors, transfer conveyors, and conveyor belts in coal mines. They are key actuators in the electrical control systems of coal mining machinery. However, the existing mining vacuum contactors have long relied mainly on imported products, and their failure rate can reach as high as approximately 25%, which has become a prominent problem affecting the continuous operation of coal mining equipment and the reliability of power supply.

[0003] Currently, most common accelerated life testing methods in engineering are single-factor tests, such as mechanical life tests, electrical life tests, vibration tests, or shock tests. However, actual underground working conditions differ significantly from conventional industrial scenarios. On the one hand, coal mining faces experience environmental stresses such as high dust, high humidity, and high pollution; on the other hand, the operation of coal mining machines is accompanied by complex loads such as significant vibration, localized impacts, grid voltage fluctuations, frequent switching, and high current interruptions. Existing research shows that strong vibrations and impacts can lead to contact micro-bounce, action time drift, bellows fatigue, weld cracking, arc reignition, and a decrease in electrical life; voltage fluctuations, in turn, directly affect the engagement and holding margins of electromagnetic mechanisms.

[0004] Therefore, while commonly used accelerated life testing methods can characterize performance changes under certain loads in their respective dimensions, they have at least the following problems when applied to mining vacuum contactors: First, single-stress tests are disconnected from actual field conditions. The actual failure of mining vacuum contactors is not determined by a single factor, but is usually the result of the coupled effects of multiple factors such as vibration, shock, voltage fluctuations, contact breaking, arc erosion, and environmental disturbances. Traditional single-factor accelerated life tests cannot reproduce the multi-factor coupled degradation characteristics and actual degradation paths of mining contactors during actual service. Second, fixed stress loading strategies cannot match different degradation stages. The life evolution of contactors often goes through multiple stages such as slow degradation, accelerated degradation, and failure precursors. If the test always uses a fixed stress level, problems such as excessively slow degradation and excessively long test cycles may occur, or excessively fast degradation and deviation from the actual failure mode may result. Secondly, the testing system and the monitoring and diagnostic system are disconnected. Although existing technologies have achieved advancements in coil current detection, contact displacement detection, main and auxiliary contact status acquisition, and upper-computer diagnostic platforms, these multi-source monitoring quantities have not yet been fully utilized in accelerated life testing to drive "adaptive adjustment of test stress" and "dynamic correction of the life mapping model." In other words, the applied stress cannot be dynamically adjusted based on the real-time degradation state of the contactor. Finally, there is a lack of a mapping mechanism between laboratory life and field life. Existing accelerated life tests can only yield test conclusions such as "failure after a certain number of operations" or "a certain structure is more durable," failing to map laboratory life results to equivalent field life, remaining life, or maintenance level. This means they cannot answer engineering questions such as: how long has the current test result equated to downhole operation? Approximately how much remaining field life is left? When should maintenance be performed? When should derating be required? Therefore, a new accelerated life testing method is urgently needed to make the testing process closer to field conditions and to make the test results more engineering interpretable and applicable. Summary of the Invention

[0005] In view of this, the present invention provides a method and system for adaptive accelerated life testing of composite stress for mining vacuum contactors, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.

[0006] To achieve the aforementioned objectives, a first aspect of the present invention provides a method for accelerated life testing of a mining vacuum contactor under combined stress, the method comprising:

[0007] Step S1: Set a composite stress spectrum based on the working conditions of the mining vacuum contactor. The composite stress includes two or more of the following: vibration stress, impact stress, voltage fluctuation stress, load breaking stress, operating frequency stress, and environmental stress.

[0008] Step S2: Apply the composite stress to the mining vacuum contactor according to the composite stress spectrum;

[0009] Step S3: Synchronously collect multi-source test data of the mining vacuum contactor;

[0010] Step S4: Extract degradation feature quantities from the multi-source experimental data;

[0011] Step S5: Calculate the comprehensive degradation index D and the current degradation rate r based on the degradation characteristic quantities;

[0012] Step S6: Compare the current degradation rate r with the preset target degradation rate interval. In comparison, when When, increase the current stress level; when When, maintain the current stress level; when At that time, reduce the current stress level.

[0013] Optionally, in the experimental method described above, the experimental method further includes:

[0014] Step S7: Combining the field correction data E of the working condition scenario, map the parameter set S of the composite stress and the set A of the degradation characteristics to the equivalent field life of the mining vacuum contactor. .

[0015] In the experimental method described above, optionally, in step S7, a mapping model is constructed, the mapping model satisfying:

[0016]

[0017]

[0018] in, Here are the field correction coefficients, and F(⋅) is the mapping model. This is the lifetime acceleration equivalent term based on the parameter set S of the composite stress. For the lifetime damage term based on the set A of the aforementioned degradation features, For the correction item based on the field correction data E, , , They are respectively The corresponding weighting coefficients.

[0019] Optionally, in the experimental method described above, the experimental method further includes:

[0020] Step S8: Based on the equivalent field life Output the equivalent field life consumption ratio, remaining life range, and / or maintenance warning level of the mining vacuum contactor.

[0021] In the test method described above, optionally, the parameters of the vibration stress include vibration frequency, vibration acceleration, vibration direction, frequency sweep interval, and / or random vibration spectrum; the parameters of the impact stress include peak impact acceleration, impact pulse width, impact direction, waveform type, and / or number of impacts; the parameters of the voltage fluctuation stress include the drop amplitude and recovery time of the control voltage, and / or fluctuation rate; the parameters of the load breaking stress include the current of the main circuit switching current, power factor, load type, and / or number of switching operations; the parameters of the operating frequency stress include the number of opening and closing operations per unit time, continuous operating length, and / or cycle configuration; and the parameters of the environmental stress include temperature, humidity, pollution level, and / or dust level.

[0022] In the test method described above, optionally, the multi-source test data includes the coil current, contact displacement, main and auxiliary contact status, vibration acceleration, and / or ambient temperature and humidity of the mining vacuum contactor.

[0023] In the test method described above, optionally, the degradation characteristics include the closing time, opening time, number of contact bounces, contact bounce duration, peak current, holding current, high current duration, contact gap change, contact overtravel change, and / or contact resistance change of the mining vacuum contactor.

[0024] In the test method described above, optionally, the comprehensive degradation index D satisfies:

[0025]

[0026] in, The number of the degenerate features. For the first A degenerate feature quantity, For the first The corresponding weights of each degenerate feature quantity satisfy the following conditions: and , The dimensionless normalization function of the degenerate characteristic quantity.

[0027] The current degradation rate r satisfies:

[0028]

[0029] in, This refers to the comprehensive degradation index within the current statistical window. This is the comprehensive degradation index within the previous adjacent statistical window. This represents the cumulative number of actions within the current statistics window. This represents the cumulative number of actions within the previous adjacent statistical window.

[0030] In the test method described above, optionally, in step S6, when adjusting the stress level, the composite stress is directionally adjusted based on the dominant change direction in the degradation characteristic quantity.

[0031] To achieve the aforementioned objectives, a second aspect of the present invention provides a composite stress adaptive accelerated life testing system for mining vacuum contactors, used to implement the testing method described above, the testing system comprising:

[0032] A composite stress loading module is used to apply composite stress to the mining vacuum contactor based on the working conditions of the mining vacuum contactor. The composite stress loading module includes one or more of the following: a vibration loading module, an impact loading module, a voltage fluctuation generation module, and a load interruption module.

[0033] A multi-source synchronous acquisition module is used to acquire multi-source test data of the mining vacuum contactor;

[0034] A degradation feature extraction module is used to extract degradation feature quantities from the multi-source experimental data;

[0035] The stress adaptive control module is used to calculate the comprehensive degradation index and the current degradation rate based on the degradation characteristic quantity, compare the current degradation rate with the preset target degradation rate range, and adjust the current stress level according to the comparison result.

[0036] The accelerated life test method of the present invention applies multiple composite stresses based on real working conditions to the vacuum contactor used in mining. This makes the test process and results more consistent with the actual conditions in coal mines. At the same time, the test stress level is dynamically adjusted according to the real-time degradation state of the vacuum contactor, so that the test is always in an effective acceleration range, thus balancing test efficiency and authenticity.

[0037] In optional embodiments, the present invention combines experimental data and field correction data to map the equivalent field life of the mining vacuum contactor, thereby achieving a quantitative description of the life evolution process in actual use. In further optional embodiments, the invention simultaneously outputs the equivalent life consumption ratio, remaining life range, and / or maintenance warning level, which can directly serve operation and maintenance decisions, improving the engineering interpretability and applicability of the experimental results.

[0038] In other alternative embodiments, stress orientation adjustment during dynamic adjustment of experimental stress levels can reduce the risk of introducing unrealistic acceleration modes due to excessive acceleration by a single stress, making the experimental process and results more realistic.

[0039] The present invention further provides a composite stress adaptive accelerated life test system for mining vacuum contactors, and therefore the test system also has the above-mentioned advantages. Attached Figure Description

[0040] The disclosure of this invention will become more apparent from the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings:

[0041] Figure 1 This is a flowchart of an embodiment of the experimental method for adaptive accelerated life testing of composite stress in a mining vacuum contactor according to the present invention.

[0042] Figure 2 This is a flowchart illustrating an embodiment of the degradation feature extraction and stress level adjustment of the present invention.

[0043] Figure 3 This is a flowchart illustrating one embodiment of the equivalent field lifetime mapping of the present invention.

[0044] Figure 4 This is a schematic diagram of an embodiment of the equivalent field lifetime evolution process model of the present invention.

[0045] Figure 5 This is a structural block diagram of an embodiment of the mine vacuum contactor composite stress adaptive accelerated life test system of the present invention. Detailed Implementation

[0046] Referring to the accompanying drawings and specific embodiments, the structure, composition, features, and advantages of the mine vacuum contactor composite stress adaptive accelerated life test method and system of the present invention will be described by way of example below. However, all descriptions should not be construed as limiting the present invention in any way.

[0047] Furthermore, for any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the various figures, the present invention still allows for any combination or deletion of these technical features (or their equivalents) without any technical obstacle, and thus these further embodiments according to the present invention should also be considered within the scope of this description.

[0048] Figure 1 This is a flowchart illustrating an embodiment of the adaptive accelerated life testing method for composite stress in a mining vacuum contactor according to the present invention. Figure 1As shown, in this embodiment, by constructing a composite stress spectrum, an accelerated life test is conducted on the tested vacuum contactor to more closely resemble the actual downhole service process. During the test, multi-source experimental data is collected simultaneously, and degradation increments are extracted from the multi-source experimental data to calculate the comprehensive degradation index and the current degradation rate. The experimental stress is then adaptively adjusted, and finally, a mapping relationship between laboratory life and equivalent field life is established by combining field correction data. The equivalent field life consumption ratio, remaining life range, and maintenance warning level are then output.

[0049] In actual operating scenarios, underground coal mine conditions typically involve high dust levels, high humidity, significant vibration, and wide-ranging voltage fluctuations in the control circuits. These voltage fluctuations can range from, for example, 60% to 120% of the rated voltage. To better reflect these real-world conditions, step S1 establishes a programmable composite stress spectrum encompassing various stress types. In this invention, the composite stress includes two or more of the following: vibration stress, impact stress, voltage fluctuation stress, load breaking stress, operating frequency stress, and environmental stress. Optionally, it may include four or more of these factors, thereby summarizing and representing the actual operating conditions of the mine vacuum contactor and accurately reflecting the underground service environment.

[0050] In optional embodiments, the parameters of vibration stress may include one or more of vibration frequency, vibration acceleration, vibration direction, sweep frequency range, and random vibration spectrum; the parameters of impact stress may include one or more of impact acceleration peak value, impact pulse width, impact direction, waveform type, and number of impacts; the parameters of voltage fluctuation stress may include one or more of the control voltage drop amplitude and its recovery time, and fluctuation rate; the parameters of load breaking stress may include one or more of the main circuit switching current, power factor, load type, and number of breaks; the parameters of operating frequency stress may include one or more of the number of opening and closing cycles per unit time, continuous action length, and cycle configuration; and the parameters of environmental stress may include one or more of temperature, humidity, pollution level, and dust level. Vibration stress, impact stress, and operating frequency stress are used to conduct accelerated life tests on the mining vacuum contactor from a mechanical structure perspective; voltage fluctuation stress and operating frequency stress are tested from an electrical structure perspective; load breaking stress is tested from an electrical life perspective; and environmental stress tests the corrosion resistance and dust resistance of its overall casing.

[0051] Based on the established composite stress spectrum, in step S2, the mine vacuum contactor under test is installed on the experimental system, and the composite stress described above is applied to it to initiate the accelerated life test. Furthermore, in step S3, multi-source test data of the mine vacuum contactor is simultaneously acquired, and a timestamp-aligned sequence of raw test data is formed for subsequent data processing. Optionally, the multi-source test data may include one or more of the following: coil current, contact displacement, main and auxiliary contact status, vibration acceleration, ambient temperature, and ambient humidity of the mine vacuum contactor. It may also include other operating parameters such as contact resistance and arc stability characteristics; this invention does not limit this.

[0052] In step S4, degradation characteristic quantities of the mining vacuum contactor are extracted from these multi-source test data. In step S5, a comprehensive degradation index D is constructed based on the degradation characteristic quantities, and the current degradation rate r is calculated. Subsequently, in step S6, the obtained current degradation rate r is compared with the preset target degradation interval. In comparison, it is determined whether the current experimental acceleration is within the target degradation range, and the current stress level is adaptively adjusted based on the comparison results.

[0053] Figure 2 This is a flowchart illustrating an embodiment of the degradation feature extraction and stress level adjustment method of the present invention. Figure 2 As can be seen from this embodiment, the degradation characteristics include the closing time, opening time, contact bounce count, and peak current of the mining vacuum contactor. In other optional embodiments, the degradation characteristics may also include one or more of the following: contact bounce duration, holding current, high current duration, contact gap change, contact overtravel change, contact resistance change, and operating time standard deviation.

[0054] In such Figure 2 In the embodiment shown, the comprehensive degradation index D is obtained by weighting the degradation features, satisfying:

[0055]

[0056] in, The number of degenerate features. For the first A degenerate feature quantity, For the first The corresponding weights of each degenerate feature quantity satisfy the following conditions: and , It is a dimensionless normalization function for the degenerate characteristic.

[0057] Since the overall degradation index D changes continuously with the number of actions or running time in actual experiments, in order to measure the current degradation rate, the experimental method of this invention further defines the current degradation rate r as:

[0058]

[0059] in, This refers to the comprehensive degradation index within the current statistical window. This is the comprehensive degradation index within the previous adjacent statistical window. This represents the cumulative number of actions within the current statistics window. This represents the cumulative number of actions within the previous adjacent statistical window. In other optional embodiments, and It can also be defined as the equivalent test time point within the current statistical window and the previous adjacent statistical window, respectively. This invention does not limit this.

[0060] In a further optional embodiment, in order to smooth the calculation results and suppress random fluctuations, methods such as moving average, exponential smoothing, or robust statistical methods can be used to smooth the comprehensive degradation index D and the current degradation rate r.

[0061] Based on actual working conditions and experimental requirements, this invention pre-determines a target degradation rate range. And compare the current degradation rate r with the target degradation rate interval. Comparison. When When, increase the current stress level; when When, maintain the current stress level; when At that time, reduce the current stress level.

[0062] Optionally, increasing the stress level can be achieved by increasing one or more stress parameters in the composite stress, such as increasing the vibration acceleration of vibration stress, increasing the peak impact acceleration of impact stress, shortening the operating cycle configuration of the operating frequency stress, and increasing the load breaking strength of the load-starting stress. Conversely, decreasing the stress level can be achieved by decreasing one or more stress parameters in the composite stress, such as decreasing the impact frequency of impact stress, the voltage fluctuation amplitude of the callback voltage fluctuation stress, and decreasing the operating frequency of the operating frequency stress, to prevent the accelerated life test process from deviating from the failure mode under real-world operating conditions. Maintaining the current stress level means continuing to sample and monitor the mining vacuum contactor at the current experimental pace. This closed-loop adaptive adjustment based on the current degradation rate ensures that the accelerated life test always operates within the effective range, thereby reducing experimental waiting time and improving experimental efficiency and realism.

[0063] Alternatively, when adjusting the stress level, to avoid unnecessary simultaneous adjustment of all composite stresses, the composite stress can be adjusted directionally based on the dominant change direction of the degradation characteristic. This reduces the risk of unrealistic failure modes caused by excessive acceleration from a single stress, making the accelerated life test process closer to real-world operating conditions.

[0064] For example, when the change in degradation characteristics is mainly caused by an abnormal increase in the number of contact bounces or the duration of contact bounces, vibration stress or impact stress should be increased first; when the change in degradation characteristics is mainly caused by an abnormal increase in the peak current or the duration of high current, voltage fluctuation stress should be adjusted first; when the change in degradation characteristics is mainly caused by an increase in the dispersion of closing time and opening time, vibration spectrum and operating frequency stress in vibration stress should be adjusted first; when the change in degradation characteristics is mainly caused by a rapid decrease in insulation margin-related characteristics, such as the change in contact gap and the change in contact overtravel, temperature and humidity or load breaking stress in environmental stress should be increased first.

[0065] Figure 1 Steps S7 and S8 shown are optional supplementary steps of the experimental method of the present invention. In this embodiment, the parameter set S of the composite stress and the set A of the degradation characteristic quantities during the experiment are combined with the field correction data E under actual working conditions to establish the laboratory life and equivalent field life of the mining vacuum contactor obtained by accelerated life experiment. The mapping model is used to further output the life assessment results of the mining vacuum contactor, such as one or more of the following: equivalent field life consumption ratio, remaining life range, and maintenance warning level.

[0066] Figure 3 This is a flowchart illustrating one embodiment of the equivalent field lifetime mapping of the present invention. Figure 3 As shown, the first part of the input values ​​of the mapping model includes the parameter set S and the set of degradation characteristics A from the composite stress in the accelerated life test, as well as the laboratory life obtained further, which can optionally be represented by the failure threshold and the number of failure actions of the mining vacuum contactor. The second part includes field correction data E, which may specifically include, for example, operating condition statistics, environmental correction items, load correction items, typical fault records and maintenance records.

[0067] Both sets of data are input into the mapping model, and optionally, the mapping model satisfies:

[0068]

[0069] in, F(⋅) represents the field correction coefficient, and F(⋅) represents the mapping model.

[0070] Alternatively, we can set:

[0071]

[0072] in, This is the lifetime acceleration equivalent term based on the parameter set S of composite stress. For the lifetime damage term based on the set A of degradation features, For correction items based on field correction data E, , , They are respectively The corresponding weighting coefficients.

[0073] At this point, if the service life of the mining vacuum contactor in the field is known... The remaining lifespan can be further calculated. :

[0074]

[0075] Therefore, the experimental results can be intuitively transformed into a quantitative description of the life evolution process of mining vacuum contactors, improving their applicability in practical engineering. Simultaneously, this quantitative result related to equivalent field life can form a closed loop with existing research on structural optimization, operating mechanism optimization, control loop optimization, and monitoring and diagnostic capabilities, which is beneficial for improving the service life of existing mining vacuum contactors.

[0076] like Figure 3 As shown in the figure, the life evolution process of a mining vacuum contactor can be divided into different stages according to the actual engineering situation. Figure 4 This is a schematic diagram of an embodiment of the equivalent field lifetime evolution model of the present invention, combined with... Figure 3 and Figure 4 As can be seen, in the optional embodiments, the evolution process of the equivalent field lifetime can be divided into three stages: slow degradation, accelerated degradation, and failure precursors. Different mapping models are established for each stage, and then segmented and spliced ​​together. This invention does not limit the specific stage division and mapping model form.

[0077] The following example illustrates one implementation of the experimental method of the present invention. In the accelerated life test, a mining vacuum contactor with a rated voltage of 3.6kV and a rated current of 400A was selected as the test object. This specification of mining vacuum contactor is one of the most commonly used specifications in underground coal mines. The mining vacuum contactor was installed in a test platform equipped with vibration loading, impact loading, voltage fluctuation generation, and main circuit load breaking functions. The test platform was also equipped with a coil current sensor, a contact displacement sensor, a main and auxiliary contact status acquisition circuit, an acceleration sensor, and a temperature and humidity sensor.

[0078] In the experiment, the parameters of the initial composite stress were set as follows: vibration frequency of 20Hz to 120Hz, vibration acceleration of 1g to 3g, impact waveform type of half-sine, peak impact acceleration of 30g, control voltage drop of 60% to 100% of rated control voltage, main circuit switching current close to rated operating conditions, number of switching operations per unit time according to a preset cycle, and ambient humidity set to simulate a humid underground environment. These composite stress parameters were all set with reference to actual engineering conditions.

[0079] During each opening and closing operation of the mining vacuum contactor, the coil current waveform, contact displacement waveform, main and auxiliary contact status, housing vibration acceleration, and environmental parameters are simultaneously collected. After each preset number of operations are completed, the following data are calculated from the multi-source experimental data as degradation characteristic quantities: average closing time, average opening time, standard deviation of closing time, number of contact bounces, cumulative duration of contact bounces, peak current deviation, holding current deviation, contact overtravel change, and contact abnormal operation rate.

[0080] Substituting these degradation characteristics into the calculation formula for the comprehensive degradation index D, we obtain the comprehensive degradation index D for the current statistical window. Based on data from adjacent statistical windows, we further calculate the current degradation rate r. We then compare the current degradation rate r with the preset target degradation rate interval. In comparison, this allows for adaptive adjustment to the current stress level.

[0081] Furthermore, the failure threshold, failure action count, degradation characteristic quantity set, and composite stress parameter set obtained from accelerated life testing are jointly modeled with environmental correction data, fault records, and maintenance records obtained from field monitoring to obtain the equivalent field life and remaining life of the mining vacuum contactor. The life consumption ratio, remaining life range, and maintenance level recommendations are then output on the host computer.

[0082] The second aspect of the present invention includes an experimental system suitable for the experimental methods described above. Figure 5This is a structural block diagram of an embodiment of the mine vacuum contactor composite stress adaptive accelerated life test system of the present invention. Figure 5 As shown, the tested mining vacuum contactor is located at the center of the experimental system. The experimental system may include a composite stress loading module, used to apply composite stress to the tested mining vacuum contactor based on actual working conditions, and specifically includes one or more of the following: a vibration loading module, an impact loading module, a voltage fluctuation generation module, and a load breaking module; a multi-source synchronous acquisition module, used to acquire multi-source test data of the mining vacuum contactor; a degradation feature extraction module, used to extract degradation feature quantities from the multi-source test data; and a stress adaptive control module, used to calculate the comprehensive degradation index and the current degradation rate based on the degradation feature quantities, compare the current degradation rate with the preset target degradation rate range, and adjust the current stress level according to the comparison result.

[0083] As an optional supplementary module, the experimental system of this invention may further include a life mapping construction module, used to combine field correction data from the working conditions to map the parameter set of composite stress and the set of degradation characteristic quantities to the equivalent field life of the mining vacuum contactor; and a host computer management module, used to realize test parameter configuration, real-time curve display, data storage, and result output. Thus, the experimental system of this invention can form a closed loop of multi-source monitoring, data analysis, and dynamic control, improving the authenticity, experimental efficiency, and applicability of the accelerated life test of the mining vacuum contactor.

[0084] The technical scope of this invention is not limited to the contents of the above specification. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the scope of this invention.

Claims

1. A method for accelerated life testing of a mining vacuum contactor under combined stress, characterized in that, The test method includes: Step S1: Set a composite stress spectrum based on the working conditions of the mining vacuum contactor. The composite stress includes two or more of the following: vibration stress, impact stress, voltage fluctuation stress, load breaking stress, operating frequency stress, and environmental stress. Step S2: Apply the composite stress to the mining vacuum contactor according to the composite stress spectrum; Step S3: Synchronously collect multi-source test data of the mining vacuum contactor; Step S4: Extract degradation feature quantities from the multi-source experimental data; Step S5: Calculate the comprehensive degradation index D and the current degradation rate r based on the degradation characteristic quantities; Step S6: Compare the current degradation rate r with the preset target degradation rate interval. In comparison, when When, increase the current stress level; when When, maintain the current stress level; when At that time, reduce the current stress level.

2. The test method as described in claim 1, characterized in that, The experimental method also includes: Step S7: Combining the field correction data E of the working condition scenario, map the parameter set S of the composite stress and the set A of the degradation characteristics to the equivalent field life of the mining vacuum contactor. .

3. The test method as described in claim 2, characterized in that, In step S7, a mapping model is constructed, which satisfies: in, Here are the field correction coefficients, and F(⋅) is the mapping model. This is the lifetime acceleration equivalent term based on the parameter set S of the composite stress. For the lifetime damage term based on the set A of the aforementioned degradation features, For the correction item based on the field correction data E, , , They are respectively The corresponding weighting coefficients.

4. The test method as described in claim 2, characterized in that, The experimental method also includes: Step S8: Based on the equivalent field life Output the equivalent field life consumption ratio, remaining life range, and / or maintenance warning level of the mining vacuum contactor.

5. The test method as described in claim 1, characterized in that, The parameters of the vibration stress include vibration frequency, vibration acceleration, vibration direction, frequency sweep interval, and / or random vibration spectrum; the parameters of the impact stress include peak impact acceleration, impact pulse width, impact direction, waveform type, and / or number of impacts; the parameters of the voltage fluctuation stress include the drop amplitude and recovery time of the control voltage, and / or fluctuation rate; the parameters of the load breaking stress include the current of the main circuit switching current, power factor, load type, and / or number of switching operations; the parameters of the operating frequency stress include the number of opening and closing operations per unit time, continuous operating length, and / or cycle configuration; the parameters of the environmental stress include temperature, humidity, pollution level, and / or dust level.

6. The test method as described in claim 1, characterized in that, The multi-source test data includes the coil current, contact displacement, main and auxiliary contact status, vibration acceleration, and / or ambient temperature and humidity of the mining vacuum contactor.

7. The test method as described in claim 1, characterized in that, The degradation characteristics include the closing time, opening time, number of contact bounces, contact bounce duration, peak current, holding current, high current duration, contact gap change, contact overtravel change, and / or contact resistance change of the mining vacuum contactor.

8. The test method of claim 1 wherein, The comprehensive degradation index D satisfies: wherein, is the number of the degradation features, is the number of the degradation features, is the number of the degradation features, is the number of the degradation features, is the number of the degradation features, and , is the number of the degradation features, The current degradation rate r satisfies: wherein, is a comprehensive degradation indicator within a current statistical window, is a comprehensive degradation indicator within a previous adjacent statistical window, is a cumulative number of actions within the current statistical window, is a cumulative number of actions within the previous adjacent statistical window.

9. The test method of claim 1 wherein, In step S6, when adjusting the stress level, the composite stress is directionally adjusted based on the dominant change direction in the degradation characteristic quantity.

10. A composite stress adaptive accelerated life test system for a mining vacuum contactor, used to implement the test method as described in claim 1, characterized in that, The test system includes: A composite stress loading module is used to apply composite stress to the mining vacuum contactor based on the working conditions of the mining vacuum contactor. The composite stress loading module includes one or more of the following: a vibration loading module, an impact loading module, a voltage fluctuation generation module, and a load interruption module. A multi-source synchronous acquisition module is used to acquire multi-source test data of the mining vacuum contactor; A degradation feature extraction module is used to extract degradation feature quantities from the multi-source experimental data; The stress adaptive control module is used to calculate the comprehensive degradation index and the current degradation rate based on the degradation characteristic quantity, compare the current degradation rate with the preset target degradation rate range, and adjust the current stress level according to the comparison result.

Images