A testing system and method for the mechanical life of an isolating grounding switch.

Abstract

This invention relates to the field of life testing technology, and discloses a testing system and method for the mechanical life of an isolating grounding switch. The system involves installing torque and angle detection elements on a switchgear with a horizontal center break. By adjusting the fixed contact to a preset displacement and applying preset loads in opposite directions to the two terminals, various displacement and load combinations are constructed. The equivalent moment of inertia is obtained through angular acceleration variation, and the quasi-static torque is calculated based on the torque and angular acceleration at the power output terminal under each condition, thereby determining the critical input torque for each condition. Further calculation and normalization of the combination difference yields the interaction coefficient. The measurement and calculation are repeated within a specified number of cycles, and the variation of the interaction coefficient with the number of cycles is recorded. Finally, the mechanical life of the switchgear is determined, achieving an accurate assessment of the mechanical performance degradation under the combined effects of load and displacement.

Description

Technical Field

[0001] This invention relates to the field of life testing technology, and more specifically, to a testing system and method for testing the mechanical life of an isolating grounding switch. Background Technology

[0002] Isolating grounding switches are key mechanical components in high-voltage power transmission and transformation equipment. They rely on an operating mechanism to drive the main cutter arm to achieve conduction or isolation within a certain angle range. Especially in horizontal center-break structures, the cutter arms on both sides rotate around the support and close at the central break, relying on a center-connecting mechanism to maintain the stability of the open and closed positions. In conventional tests, researchers usually treat end loads and contact area displacement as independent influencing factors, measuring mechanical durability only under a single condition. However, with the increase in voltage levels and the widespread adoption of lightweight structural designs, the stiffness and deflection of the support, cutter arms, and conductive connections have gradually become variables affecting the stability of the mechanism's motion. When the test simultaneously applies end forces and sets vertical displacement according to standard requirements, the slight changes in the overall posture of the device will cause a slight shift in the contact position between the cutter arm and the fixed contact, causing a nonlinear change in the transmission angle relationship of the center-connecting mechanism. This nonlinear change accumulates with each opening and closing cycle, eventually causing the peak input torque to no longer have a linear relationship with a single parameter, resulting in test fluctuations and uncertainties in the life curve.

[0003] From a mechanical perspective, the terminal contact of a center-break disconnector relies on the guiding cooperation of the bell mouth and the contact fingers. When vertical displacement exists, the rotation path of the cutter arm forms a slight angle with the axis of the bell mouth. Simultaneously, the static load applied in the opposite direction at the end causes a slight pitching of the support system, causing the force direction on the contact to deviate from the main drive line of the mechanism. With these two conditions superimposed, the input torque acting on the through-center linkage system no longer depends solely on structural parameters or a single load, but is jointly determined by the nonlinear relationship between multiple forces and displacements. Because existing test procedures only specify loading conditions and acceptance criteria, and do not include methods for torque measurement and analysis under this combined state, the lifespan results obtained for the same equipment vary significantly under different test benches or arrangements. Summary of the Invention

[0004] This invention provides a testing system and method for the mechanical life of an isolating grounding switch, which solves the technical problem of how to accurately quantify the variation law of the through-center torque under the combined action of vertical offset and end load under mechanical life test conditions, so as to obtain repeatable and representative life test results.

[0005] In a first aspect, the present invention provides a method for testing the mechanical life of an isolating grounding switch, comprising:

[0006] In a switchgear with a horizontal center break, a torque detection element and an angle detection element are installed at the power output end of the operating mechanism;

[0007] Adjust the fixed contact to the preset displacement, and apply preset loads in opposite directions to the terminals on both sides of the switchgear. The preset load is a preset ratio of the rated static end load.

[0008] The equivalent moment of inertia is obtained by changing the angular acceleration; multiple working conditions are set, including combinations of displacement and load, and the quasi-static torque is calculated based on the torque at the power output end, the equivalent moment of inertia, and the corresponding angular acceleration under each working condition.

[0009] Determine the critical input torque based on the quasi-static torque under each operating condition;

[0010] The combination difference is calculated based on the critical input torque of each working condition, and then the interaction coefficient is obtained by normalization with preset displacement and preset load.

[0011] Under the condition of keeping the preset displacement and preset load unchanged, complete a specified number of mechanical action cycles, repeatedly calculate the working condition measurement and interaction coefficient at the preset cycle node, record the characteristic change of the interaction coefficient with the number of cycles, and determine the mechanical life of the switchgear corresponding to the characteristic change.

[0012] Secondly, a testing system for the mechanical life of an isolating grounding switch, applied in any of the methods for testing the mechanical life of an isolating grounding switch described in any one of the claims, includes:

[0013] The first module, on a switchgear with a horizontal center break, includes a torque detection element and an angle detection element installed at the power output end of the operating mechanism;

[0014] The second module adjusts the fixed contact to a preset displacement and applies preset loads in opposite directions to the terminals on both sides of the switchgear. The preset load is a preset ratio of the rated static end load.

[0015] The third module obtains the equivalent moment of inertia through angular acceleration variation operations; it sets up multiple working conditions including combinations of displacement and load, and calculates the quasi-static torque based on the torque at the power output end, the equivalent moment of inertia, and the corresponding angular acceleration under each working condition.

[0016] The fourth module determines the critical input torque based on the quasi-static torque under each operating condition;

[0017] The fifth module calculates the combination difference based on the critical input torque of each working condition, and then normalizes it with preset displacement and preset load to obtain the interaction coefficient.

[0018] The sixth module completes a specified number of mechanical action cycles while keeping the preset displacement and preset load constant. At the preset cycle nodes, the operating condition measurement and interaction coefficient are repeatedly calculated, the characteristic changes of the interaction coefficient with the number of cycles are recorded, and the mechanical life of the switching equipment corresponding to the characteristic changes is determined.

[0019] The beneficial effects of this invention include: by setting torque and angle detection elements at the power output end of the operating mechanism, measuring the equivalent moment of inertia in conjunction with changes in angular acceleration, and calculating the quasi-static torque and critical input torque under different displacement and load combinations, quantitative analysis of displacement, load, and their interaction effects is achieved. By introducing the interaction coefficient and its variation law with the number of cycles, the performance degradation trend and mechanical life characteristics of the switching mechanism under combined stress conditions can be accurately identified. This method effectively overcomes the problems of traditional testing, which only considers a single parameter, has large fluctuations in results, and poor repeatability. It significantly improves the repeatability and representativeness of life testing, providing a scientific basis for the structural optimization and reliability assessment of high-voltage isolating grounding switches. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for testing the mechanical life of an isolating grounding switch according to the present invention;

[0021] Figure 2 This is a block diagram of a testing system for the mechanical life of an isolating grounding switch according to the present invention. Detailed Implementation

[0022] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0023] Example 1

[0024] like Figure 1 As shown, a test method for the mechanical life of an isolating grounding switch includes:

[0025] In a switchgear with a horizontal center break, a torque detection element and an angle detection element are installed at the power output end of the operating mechanism;

[0026] Adjust the fixed contact to the preset displacement, and apply preset loads in opposite directions to the terminals on both sides of the switchgear. The preset load is a preset ratio of the rated static end load.

[0027] The equivalent moment of inertia is obtained by changing the angular acceleration; multiple working conditions are set, including combinations of displacement and load, and the quasi-static torque is calculated based on the torque at the power output end, the equivalent moment of inertia, and the corresponding angular acceleration under each working condition.

[0028] Determine the critical input torque based on the quasi-static torque under each operating condition;

[0029] The combination difference is calculated based on the critical input torque of each working condition, and then the interaction coefficient is obtained by normalization with preset displacement and preset load.

[0030] Under the condition of keeping the preset displacement and preset load unchanged, complete a specified number of mechanical action cycles, repeatedly calculate the working condition measurement and interaction coefficient at the preset cycle node, record the characteristic change of the interaction coefficient with the number of cycles, and determine the mechanical life of the switchgear corresponding to the characteristic change.

[0031] In one embodiment of the present invention, in a switching device having a horizontal center break, a torque detection element and an angle detection element are provided at the power output end of the operating mechanism, including:

[0032] The angle detection element outputs the raw angle signal;

[0033] The torque detection element outputs the raw torque signal;

[0034] The raw angle and raw torque signals are sampled at a fixed sampling period;

[0035] Calculate the corresponding angular velocity based on the original angle signal and sampling period;

[0036] Calculate the corresponding angular acceleration based on the corresponding angular velocity and sampling period;

[0037] The torque measurement value at the power output end is calculated based on the original torque signal and the zero-point offset of the torque detection element.

[0038] No. angular velocity corresponding to each sampling point ;in, Indicates the first The original angle signal of each sampling point Indicates the first The original angle signal of each sampling point Indicates the sampling period.

[0039] No. angular acceleration corresponding to each sampling point ;in, For the first angular velocity at each sampling point For the first angular velocity of each sampling point.

[0040] Torque measurement at power output end ;in, This is the zero-point offset of the torque sensing element. The torque physical quantity is collected in real time by the torque detection element.

[0041] The angle detection element directly outputs a raw signal that reflects the rotation angle of the power output end of the operating mechanism (i.e., the raw angle signal), which can be directly associated with the rotation position of the output end; the torque detection element directly outputs a raw signal that reflects the magnitude of the torque received by the power output end (i.e., the raw torque signal).

[0042] To ensure the temporal correspondence between angle and torque data (and avoid calculation errors caused by time asynchrony), the original angle and torque signals must be collected synchronously at fixed time intervals (i.e., sampling periods) to ensure that each set of angle and torque data corresponds to the mechanism state at the same moment.

[0043] Angular acceleration is used to reflect the rate of change of rotational speed at the power output end. During calculation, the angular velocity of the i-th sampling point is first obtained, and then the angular velocity of the previous sampling point (i.e., the (i-1)-th sampling point) is subtracted to obtain the change in angular velocity between the two sampling points. This change in angular velocity is then divided by a fixed sampling period, and the result is the angular acceleration corresponding to the i-th sampling point.

[0044] When the torque sensing element is not subjected to actual torque, it may exhibit a slight initial offset signal (i.e., zero-point offset). This offset can lead to inaccurate torque data when directly collected. Therefore, the torque physical quantity collected in real time by the torque sensing element must be subtracted from its own zero-point offset to obtain the true torque measurement value at the power output end, ensuring the accuracy of subsequent torque-related calculations.

[0045] In one embodiment of the present invention, adjusting the fixed contact to a preset displacement and applying preset loads in opposite directions to the terminals on both sides of the switching device includes:

[0046] Determine the height of the fixed contact at the reference position and the adjusted position height. Obtain the actual displacement by the difference between the two. Adjust the actual displacement to match the preset displacement target value.

[0047] Determine the rated static end load and preset proportional value of the switchgear under test, and determine the nominal applied load amplitude of the two terminals based on the rated static end load and preset proportional value;

[0048] Apply a load equal to the nominal applied load amplitude to the left terminal, and apply a load equal to the nominal applied load amplitude but opposite in direction to the right terminal.

[0049] The nominal applied load amplitude of the two terminals is ;in, This indicates the preset load ratio coefficient. This indicates the rated static end load of the switchgear under test.

[0050] First, determine the reference position of the fixed contact (i.e., the standard installation height of the contact set during equipment design, serving as a reference for displacement measurement) and the adjusted position (the target position to be adjusted to simulate vertical offset caused by icing, temperature deformation, etc. in actual working conditions). By measuring the height difference between the two positions, the actual displacement of the contact is obtained. Then, by fine-tuning the contact position, the actual displacement is made to be completely consistent with the preset displacement target value (the displacement amount set according to test requirements or the boundary of the equipment contact area), ensuring that the displacement parameters meet the working condition requirements set for the test.

[0051] The rated static end load of the switchgear under test (the upper limit of the static end load that the equipment can withstand for a long time as specified in the equipment design, which is the basis for load setting).

[0052] The preset ratio value (the ratio set according to the mechanical durability test standard or test requirements, usually 50% of the rated static end load) is used to multiply the rated static end load by the preset ratio value to obtain the nominal applied load amplitude of the two terminals. This amplitude is the load size that needs to be applied to each terminal during the test, ensuring that the load parameters meet the test standards and working condition simulation requirements.

[0053] According to the determined nominal load amplitude, apply a load of that amplitude to the left terminal of the switchgear; simultaneously apply a load of equal magnitude but opposite direction to the right terminal. The reverse application is designed to simulate the reverse forces (such as conductor tension differences) that the two sides of the switch may experience in actual operation, making the test conditions closer to the actual use scenario of the equipment.

[0054] In one embodiment of the present invention, the equivalent moment of inertia is obtained through angular acceleration variation operation; multiple working conditions including combinations of displacement and load are set, and under each working condition, the quasi-static torque is calculated based on the torque at the power output end, the equivalent moment of inertia, and the corresponding angular acceleration, including:

[0055] Determine the angular velocity setpoint and acceleration time setpoint, and execute the acceleration operation to linearly increase the angular velocity from zero to the angular velocity setpoint.

[0056] The first average torque measurement value is obtained within the stabilization time window at the start of the acceleration operation, and the second average torque measurement value is obtained within the stabilization time window at the end of the acceleration operation.

[0057] Calculate the difference between the average value of the first torque measurement and the average value of the second torque measurement to obtain the torque measurement increment; determine the nominal angular acceleration based on the angular velocity setting and the acceleration time setting, and then determine the equivalent moment of inertia based on the torque measurement increment and the nominal angular acceleration;

[0058] Determine the displacement switch status and load switch status. A displacement switch status of zero indicates no displacement, and a status of one indicates displacement. A load switch status of zero indicates no load, and a status of one indicates load.

[0059] The displacement of each working condition is determined according to the displacement switch status and the preset displacement target value. The load amplitude of each working condition is determined according to the load switch status and the nominal applied load amplitude of the two terminals, forming a working condition with no displacement and no load, a working condition with displacement and no load, a working condition with no displacement and load, and a working condition with displacement and load.

[0060] Under each operating condition, the torque measurement value and corresponding angular acceleration at the power output end are acquired in real time;

[0061] The inertial torque is calculated by multiplying the equivalent moment of inertia and the corresponding angular acceleration.

[0062] Subtract the inertial torque from the measured torque at the power output end to obtain the quasi-static torque for each operating condition.

[0063] First, determine the angular velocity setting (the target rotational speed to be achieved) and the acceleration time setting (the time from rest to the target speed). Then, control the power output of the operating mechanism to accelerate in a linear manner from 0 to the set value, ensuring that the acceleration process is controllable and meets the test requirements.

[0064] To avoid signal fluctuations during acceleration start-stop, multiple torque measurements are collected and averaged within the stabilization time window at the beginning of acceleration (the period when the signal is stable in the initial stage of acceleration) to obtain the first torque measurement average. Similarly, multiple torque values ​​are collected and averaged within the stabilization time window at the end of acceleration (the period when the signal is stable at the end of acceleration) to obtain the second torque measurement average. Thirdly, the first torque measurement average is subtracted from the second torque measurement average to obtain the torque measurement increment (the change in torque during acceleration). Combining the angular velocity setpoint and the acceleration time setpoint, the nominal angular acceleration (the average angular acceleration during acceleration) is calculated by dividing the angular velocity setpoint by the acceleration time. Finally, the equivalent moment of inertia is obtained by dividing the torque measurement increment by the nominal angular acceleration.

[0065] First, define the displacement switch state and the load switch state: a displacement switch state of 0 represents no fixed contact displacement (no displacement), and a state of 1 represents displacement (displacement exists, according to the preset displacement target value); a load switch state of 0 represents no terminal load applied (no load), and a state of 1 represents a load applied (load exists, according to the nominal load amplitude applied to both terminals). Then, based on the combination of the two switch states, determine four test conditions: Displacement 0 + Load 0 (no displacement, no load), Displacement 1 + Load 0 (displacement exists, no load), Displacement 0 + Load 1 (no displacement, load exists), and Displacement 1 + Load 1 (displacement exists, load exists). These four conditions cover scenarios where displacement and load act individually and together.

[0066] Under each operating condition, the torque measurement value at the power output end (the true torque after deducting the zero-point offset of the torque detection element) and the corresponding angular acceleration (rotational acceleration at the power output end) are collected in real time. First, the inertial torque (the dynamic torque component generated by the mechanism's inertia during rotation) is calculated by multiplying the equivalent moment of inertia by the corresponding angular acceleration. Then, the inertial torque is subtracted from the torque measurement value at the power output end to obtain the quasi-static torque. This torque eliminates dynamic inertial interference and only reflects the static force on the mechanism under the current operating condition.

[0067] In one embodiment of the present invention, determining the critical input torque based on the quasi-static torque under various operating conditions includes:

[0068] Under unloaded conditions, passing through the center, we obtain the zero-point angle passing through the center;

[0069] Obtain the raw angle signal output by the angle detection element, and subtract the zero-point angle from the raw angle signal to obtain the relative angle used to locate the neighborhood of the center.

[0070] Set the half-width of the angle window around the zero point of the center, and determine the symmetrical interval from the negative half-width of the angle window to the positive half-width of the angle window with the zero point of the center as the center;

[0071] Under each operating condition, the quasi-static torques whose relative angles fall within the symmetrical range are selected; the maximum value of the quasi-static torques within the symmetrical range under each operating condition is taken as the critical input torque for that operating condition.

[0072] relative angle ;in, Represents the original angle signal. This is the zero-point angle at the center when the switching device passes through the center under no-load conditions.

[0073] First, allow the switch to complete one center-crossing movement under no-load conditions (without applying terminal load). No load eliminates the interference of load on the center-crossing position, ensuring that the center-crossing angle reference determined by the mechanism's own structure is obtained. This reference angle is the zero-point angle of the center-crossing.

[0074] After acquiring the raw angle signal output by the angle detection element in real time, the angle passing through the center zero point is subtracted from the raw signal to obtain the relative angle. This eliminates the influence of installation deviations of different equipment or differences in initial angle references, and uniformly converts all angle data into coordinates based on the center reference to locate the area near the center (i.e., the center neighborhood).

[0075] Set an angle window half-width (e.g., 2°) around the zero-point angle, forming a symmetrical interval from the negative half-width to the positive half-width. When passing the center, the input torque of the mechanism will reach a peak. By focusing only on the torque data within this interval, invalid data in non-center areas can be eliminated, reducing irrelevant interference.

[0076] Under each test condition, the quasi-static torques within the aforementioned symmetrical range are first selected (only effective torque data in the neighborhood of the center are retained); then, the maximum value is taken from these effective data, which is the critical input torque. Since the mechanism needs to overcome the maximum resistance to complete the action when passing the center, this maximum quasi-static torque precisely reflects the critical driving force required for the mechanism to pass the center under this condition, and is a parameter for evaluating the mechanism's performance when passing the center.

[0077] In one embodiment of the present invention, the combination difference is calculated based on the critical input torque of each working condition, and then the interaction coefficient is obtained by normalization with a preset displacement and a preset load, including:

[0078] Determine the critical input torques corresponding to the no-displacement and no-load condition, the displacement and no-load condition, the no-displacement and loaded condition, and the displacement and loaded condition, respectively.

[0079] The critical input torque under the condition of displacement and load is used to successively subtract the critical input torque under the condition of displacement and no load, and the critical input torque under the condition of no displacement and load, and then add the critical input torque under the condition of no displacement and no load to obtain the combined difference.

[0080] Determine the preset displacement target value and the nominal applied load amplitude of the two terminals. The preset displacement target value is the preset displacement target value used when adjusting the fixed contact to the preset displacement. The nominal applied load amplitude of the two terminals is the nominal applied load amplitude of the two terminals used when applying loads in opposite directions to the two terminals.

[0081] The interaction coefficient is obtained by dividing the combined difference by the product of the preset displacement target value and the nominal applied load amplitude of both terminals.

[0082] First, define the critical input torque corresponding to the four test conditions. These are: the critical input torque under the condition of no displacement and no load (reflecting only the basic resistance of the mechanism itself), the critical input torque under the condition of displacement and no load (reflecting the additional resistance of displacement acting alone), the critical input torque under the condition of no displacement and load (reflecting the additional resistance of load acting alone), and the critical input torque under the condition of displacement and load (reflecting the total resistance of displacement and load acting together).

[0083] Using the critical input torque under displacement and load conditions as the benchmark for total resistance, first subtract the critical input torque under displacement but no load conditions (eliminating the resistance caused by displacement alone), then subtract the critical input torque under no displacement but load conditions (eliminating the resistance caused by load alone). Since the critical input torque under no displacement and no load conditions is repeatedly eliminated, it needs to be added back. The final result is the combined difference. This difference only reflects the additional resistance generated when displacement and load act together, exceeding the sum of their individual effects; that is, the contribution of their interaction.

[0084] Preset displacement target value (the target displacement amount set when adjusting the displacement of the fixed contact, which serves as the reference for the displacement parameters).

[0085] The nominal applied load amplitude of both terminals (the load magnitude determined when the reverse load of the terminals was previously applied, which serves as the reference for the load parameters) is used to ensure that the normalization basis is consistent with the operating condition parameters set in the test.

[0086] The interaction coefficient is obtained by dividing the combined difference by the product of the preset displacement target value and the nominal applied load amplitude at both ends. This eliminates the influence of the specific numerical values ​​of displacement and load, transforming the contribution of the interaction into a unified coefficient independent of the parameter magnitude. This coefficient characterizes the intensity of the interaction between displacement and load.

[0087] In one embodiment of the present invention, a predetermined number of mechanical action cycles are completed while maintaining a preset displacement and preset load. At preset cycle nodes, the operating condition measurements and interaction coefficients are repeatedly calculated. The characteristic changes of the interaction coefficients with the number of cycles are recorded, and the mechanical life of the switching equipment corresponding to these characteristic changes is determined. This includes:

[0088] Maintaining the preset displacement target value and the nominal applied load amplitude of both terminals unchanged, complete the specified number of mechanical opening and closing cycles;

[0089] Determine several specific number of iterations in advance as preset loop nodes;

[0090] At each preset cycle node, the critical input torque for each working condition is measured, the combined difference is calculated, and the interaction coefficient at that preset cycle node is obtained based on the combined difference, the preset displacement target value, and the nominal applied load amplitude of the two terminals.

[0091] Obtain the interaction coefficient when the number of loops is zero, and use this interaction coefficient as the initial interaction coefficient;

[0092] For each preset loop node, subtract the initial interaction coefficient from the interaction coefficient at that node, and then divide the difference by the absolute value of the initial interaction coefficient to obtain the relative change in the interaction coefficient at that preset loop node.

[0093] Determine the preset relative change limit;

[0094] Among all preset cycle nodes, the minimum number of cycles with an absolute value greater than or equal to the preset relative change limit of the interaction coefficient is selected as the mechanical life of the switching device.

[0095] Loop count The interaction coefficient at the location is ;in, Indicates the preset target displacement value. Apply the nominal load amplitude to both terminals. Number of loops The combined difference at the location.

[0096] The initial interaction coefficient is That is, the number of cycles Interaction coefficients at time.

[0097] Loop count The relative change at that point is ;in, It is an absolute value.

[0098] Throughout the test, the preset displacement target value (the set displacement of the fixed contact) and the nominal applied load amplitude of the two terminals (the magnitude of the reverse load on both terminals) remain constant. This eliminates the interference of displacement and load parameter changes on the test results, ensuring that performance changes during the cycle only come from life-related factors such as mechanical wear of the switch itself and component fatigue. Under these conditions, the test completes a specified number of mechanical opening and closing cycles (e.g., 1000 times) to simulate the opening and closing operations of the switch in actual use.

[0099] Pre-define multiple specific loop counts as preset loop nodes (e.g., 0, 300, 900, 1000 loops). This eliminates the need to measure every single loop; selecting key nodes efficiently tracks performance trends, avoids redundant data, and ensures coverage of the initial, middle, and final stages of the loop.

[0100] Repeat the previous test process at each preset loop node:

[0101] The critical input torque is measured under four operating conditions (no displacement and no load, displacement and no load, no displacement and load, and displacement and load). The combined difference (reflecting the contribution of the interaction between displacement and load) is calculated. The combined difference is then divided by the product of the preset displacement target value and the nominal applied load amplitude of the two terminals to obtain the interaction coefficient corresponding to that node. This ensures that the calculation method of the interaction coefficient of each node is consistent with the initial state, and that the data is comparable.

[0102] The interaction coefficient when the number of cycles is zero (i.e., before the test begins, the equipment has not undergone any mechanical cycles) is taken as the initial interaction coefficient. This coefficient represents the intensity of the interaction between displacement and load in the initial mechanical state of the equipment.

[0103] For each preset loop node, the interaction coefficient of that node is subtracted from the initial interaction coefficient to obtain the absolute change in the interaction coefficient; then, this absolute change is divided by the absolute value of the initial interaction coefficient to obtain the relative change. This eliminates the influence of the initial interaction coefficient and uniformly measures the degree of performance degradation at different nodes (whether the initial coefficient is large or small, the relative change can objectively reflect the degradation ratio).

[0104] A preset relative change limit (preferably 20%) is determined. This limit is the critical standard for determining whether the mechanical performance of the equipment has failed. When the relative change of the interaction coefficient exceeds this limit, it indicates that the interaction intensity between displacement and load has changed significantly, and the mechanical performance of the equipment has deteriorated to the point that it can no longer meet the usage requirements.

[0105] Among all preset cycle nodes, nodes whose absolute value of the relative change in the interaction coefficient is greater than or equal to the preset relative change limit are selected, and the minimum number of cycles is taken as the mechanical life of the switching device. This minimum number of cycles is the number of cycles required for the device to first exhibit substandard performance.

[0106] Example 2

[0107] like Figure 2 As shown, a test system for the mechanical life of an isolating grounding switch, applied in any of the test methods for the mechanical life of an isolating grounding switch described above, includes:

[0108] The first module, on a switchgear with a horizontal center break, includes a torque detection element and an angle detection element installed at the power output end of the operating mechanism;

[0109] The second module adjusts the fixed contact to a preset displacement and applies preset loads in opposite directions to the terminals on both sides of the switchgear. The preset load is a preset ratio of the rated static end load.

[0110] The third module obtains the equivalent moment of inertia through angular acceleration variation operations; it sets up multiple working conditions including combinations of displacement and load, and calculates the quasi-static torque based on the torque at the power output end, the equivalent moment of inertia, and the corresponding angular acceleration under each working condition.

[0111] The fourth module determines the critical input torque based on the quasi-static torque under each operating condition;

[0112] The fifth module calculates the combination difference based on the critical input torque of each working condition, and then normalizes it with preset displacement and preset load to obtain the interaction coefficient.

[0113] The sixth module completes a specified number of mechanical action cycles while keeping the preset displacement and preset load constant. At the preset cycle nodes, the operating condition measurement and interaction coefficient are repeatedly calculated, the characteristic changes of the interaction coefficient with the number of cycles are recorded, and the mechanical life of the switching equipment corresponding to the characteristic changes is determined.

[0114] The embodiments of this example have been described above. However, this example is not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of this example, and all of them are within the protection scope of this example.

Claims

1. A method of testing the mechanical life of an isolated ground switch, characterized in that, The application relates to a torque detection element and an angle detection element arranged on a power output end of an operating mechanism of a switch device with a horizontal center fracture. The fixed contact is adjusted to a preset displacement, preset loads in opposite directions are applied to the terminals on both sides of the switch device, and the preset loads are preset proportional values of rated static end load; Equivalent rotational inertia is obtained through angular acceleration change operation; a plurality of working conditions containing displacement and load combinations are set, and in each working condition, quasi-static torque is calculated based on the power output end torque and the equivalent rotational inertia and the corresponding angular acceleration; The critical input torque is determined according to the quasi-static torque of each working condition; The critical input torques corresponding to the no-displacement no-load working condition, the displacement no-load working condition, the no-displacement load working condition and the displacement load working condition are determined, and are respectively the critical input torque of the no-displacement no-load working condition, the critical input torque of the displacement no-load working condition, the critical input torque of the no-displacement load working condition and the critical input torque of the displacement load working condition; The critical input torque of the displacement load working condition is used to sequentially subtract the critical input torque of the displacement no-load working condition, the critical input torque of the no-displacement load working condition, and then add the critical input torque of the no-displacement no-load working condition to obtain a combination difference value; The preset displacement target value and the nominal load amplitude of the two terminals are determined, the preset displacement target value is a preset displacement target value used when the fixed contact is adjusted to the preset displacement, and the nominal load amplitude of the two terminals is a nominal load amplitude of the two terminals used when the loads in opposite directions are applied to the terminals on both sides; The interaction coefficient is obtained by dividing the combination difference value by the product of the preset displacement target value and the nominal load amplitude of the two terminals; The preset displacement target value and the nominal load amplitude of the two terminals are kept unchanged, and a specified number of mechanical opening and closing cycles are completed; A plurality of specific cycle numbers are determined as preset cycle nodes; At each preset cycle node, the critical input torque of each working condition is measured, the combination difference value is calculated, and the interaction coefficient at the preset cycle node is obtained based on the combination difference value, the preset displacement target value and the nominal load amplitude of the two terminals; The interaction coefficient corresponding to the cycle number of zero is obtained, and the interaction coefficient is taken as an initial interaction coefficient; For each preset cycle node, the interaction coefficient at the node is subtracted from the initial interaction coefficient, and then the difference value is divided by the absolute value of the initial interaction coefficient to obtain the relative change amount of the interaction coefficient at the preset cycle node; A preset relative change limit value is determined; In all preset cycle nodes, the minimum cycle number with the absolute value of the relative change amount of the interaction coefficient greater than or equal to the preset relative change limit value is selected as the mechanical life of the switch device. The application relates to a torque detection element and an angle detection element arranged on a power output end of an operating mechanism of a switch device with a horizontal center fracture, comprising:

2. The method of claim 1, wherein the method further comprises: The angle detection element outputs an angle original signal; The torque detection element outputs a torque original signal; The angle original signal and the torque original signal are sampled at a fixed sampling period; The corresponding angular velocity is calculated based on the angle original signal and the sampling period; The corresponding angular acceleration is calculated based on the corresponding angular velocity and the sampling period; ​ The torque measurement value of the power output end is calculated based on the torque original signal and the zero point offset of the torque detection element.

3. The method of claim 2, wherein the method further comprises: The fixed contact is adjusted to a preset displacement, and preset loads in opposite directions are applied to the terminals on both sides of the switch device, including: The height of the fixed contact at the reference position and the height of the adjusted position are determined, and the actual displacement is obtained by the difference between the two, and the actual displacement is adjusted to be consistent with the preset displacement target value; The rated static end load of the test switch device and the preset proportion value are determined, and the nominal applied load amplitude of the two terminals is determined according to the rated static end load and the preset proportion value; The load equal to the nominal applied load amplitude is applied to the left terminal, and the load equal to the nominal applied load amplitude and in the opposite direction is applied to the right terminal.

4. The method of testing the mechanical life of an isolating earthing switch according to claim 3, characterized in that, The equivalent moment of inertia is obtained through the angular acceleration change operation; a plurality of working conditions containing combinations of displacement and load are set, and in each working condition, the quasi-static torque is calculated based on the power output end torque and the equivalent moment of inertia and the corresponding angular acceleration, including: The angular velocity set value and the acceleration time set are determined, and the acceleration operation of linearly increasing the angular velocity from zero base to the angular velocity set value is performed; The first torque measurement average is obtained within a stable time window at the beginning of the acceleration operation, and the second torque measurement average is obtained within a stable time window at the end of the acceleration operation; The difference between the first torque measurement average and the second torque measurement average is calculated to obtain the torque measurement increment; the nominal angular acceleration is determined according to the angular velocity set value and the acceleration time set, and the equivalent moment of inertia is determined according to the torque measurement increment and the nominal angular acceleration; The displacement switch state and the load switch state are determined, and the displacement switch state is zero indicating no displacement and one indicating displacement, and the load switch state is zero indicating no load and one indicating load; The displacement of each working condition is determined according to the displacement switch state and the preset displacement target value, and the load amplitude of each working condition is determined according to the load switch state and the nominal applied load amplitude of the two terminals, forming the no displacement no load working condition, the displacement no load working condition, the no displacement load working condition and the displacement load working condition; In each working condition, the power output end torque measurement value and the corresponding angular acceleration are obtained in real time; The inertia torque is calculated according to the product of the equivalent moment of inertia and the corresponding angular acceleration; The quasi-static torque of each working condition is obtained by subtracting the inertia torque from the power output end torque measurement value.

5. A method of testing the mechanical life of an isolating earthing switch according to claim 4, characterized in that, The critical input torque is determined according to the quasi-static torque of each working condition, including: The center crossing zero point angle is obtained by crossing the center under no load condition; The angle original signal output by the angle detection element is obtained, and the relative angle for positioning the center crossing neighborhood is obtained by subtracting the center crossing zero point angle from the angle original signal; The angle window half-width is set around the center crossing zero point angle, and the symmetric interval centered on the center crossing zero point angle from the negative angle window half-width to the positive angle window half-width is determined; In each working condition, the quasi-static torque whose relative angle is in the symmetric interval is selected; the maximum value of the quasi-static torque in the symmetric interval in each working condition is taken as the critical input torque of the working condition.

6. A test system for mechanical life of an isolating grounding switch, applied to the test method for mechanical life of an isolating grounding switch according to any one of claims 1-5, characterized in that, It includes: The first module is arranged on the switch device with a horizontal center fracture, and the torque detection element and the angle detection element are arranged on the power output end of the operating mechanism. The second module adjusts the fixed contact to a preset displacement, and applies preset loads in opposite directions on the terminals on both sides of the switch device, the preset loads being preset proportional values of the rated static end load; The third module obtains equivalent rotational inertia through angular acceleration change operation; sets multiple working conditions containing combinations of displacement and load, and calculates quasi-static torque based on the dynamic output end torque and the equivalent rotational inertia and the corresponding angular acceleration in each working condition; The fourth module determines the critical input torque according to the quasi-static torque in each working condition; The fifth module calculates the combination difference value according to the critical input torque in each working condition, and then normalizes the preset displacement and the preset load to obtain the interaction coefficient; The sixth module completes a mechanical action cycle of a specified number of times under the condition that the preset displacement and the preset load remain unchanged, repeatedly calculates the working condition measurement and the interaction coefficient at preset cycle nodes, records the characteristic change of the interaction coefficient with the cycle number, and determines the mechanical life of the switch device corresponding to the characteristic change.

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