Three-station mechanism overload protection method and system

Abstract

The present application relates to a kind of overload protection method and system of three-station mechanism, it is related to the field of electrical equipment, it includes: collection rotation parameter;From the initial load in the rotation parameter is called, and load type is determined according to initial load;In response to the load type, call reference torque curve, and extract rotation angle from the rotation parameter;Reference torque is called from reference torque curve based on the rotation angle, and correction coefficient is determined according to the initial load;Combination reference torque and correction coefficient determine locked-rotor threshold, and extract rotation torque from the rotation parameter;When the rotation torque is greater than locked-rotor threshold, determine deceleration damping according to the rotation torque;According to the deceleration damping, determine deceleration current;In response to the deceleration current, generate and send damping adjustment instruction.The present application has the effect of improving the stability of three-station mechanism operation, reducing the situation that three-station mechanism is damaged due to torque overload.

Description

Technical Field

[0001] This invention relates to the field of electrical equipment, and in particular to an overload protection method and system for a three-station mechanism. Background Technology

[0002] A three-position mechanism refers to a device in high-voltage switchgear (such as ring main units, medium-voltage switchgear, and GIS switchgear) that integrates the switching and precise positioning of three functional positions: working position, isolation position, and connection position.

[0003] In the prior art, the three-station mechanism includes three stationary contacts, corresponding to the working position, the isolation position, and the contact position, respectively. The three-station mechanism includes a motor that drives the moving contact to move. The motor outputs a certain torque to control the moving contact to contact or separate from the stationary contact in order to control the working state of the high-voltage switchgear.

[0004] Three-station mechanisms are prone to wear and aging during use, which can lead to excessive torque output from the motor and consequently damage to the equipment. Summary of the Invention

[0005] To improve the operational stability of a three-station mechanism and reduce damage caused by torque overload, this invention provides an overload protection method and system for a three-station mechanism.

[0006] In a first aspect, the present invention provides an overload protection method for a three-station mechanism, which adopts the following technical solution:

[0007] A method for overload protection of a three-station mechanism includes:

[0008] Step 100: Collect rotation parameters;

[0009] Step 101: Retrieve the initial load from the rotation parameters and determine the load type based on the initial load;

[0010] Step 102: Retrieve the reference torque curve in response to the load type, and extract the rotation angle from the rotation parameters;

[0011] Step 103: Based on the rotation angle, retrieve the reference torque from the reference torque curve and determine the correction coefficient according to the initial load;

[0012] Step 104: Determine the stall threshold by combining the reference torque and the correction coefficient, and extract the rotational torque from the rotational parameters;

[0013] Step 105: When the rotational torque is greater than the stall threshold, determine the deceleration damping based on the rotational torque;

[0014] Step 106: Determine the deceleration current according to the aforementioned deceleration damping;

[0015] Step 107: In response to the deceleration current generation, a damping adjustment command is sent.

[0016] By adopting the above technical solution, the rotation parameters of the three-station mechanism are collected in real time. Based on the initial load, the load type is accurately defined and the corresponding reference torque curve is retrieved. Then, the stationary contact of the moving contact is determined by the rotation angle of the moving contact. Then, a suitable stall threshold is matched according to the torque of different stationary contacts, so as to accurately detect the torque overload. The magnetorheological damper is used to apply damping to the torque overload, thereby reducing the damage to the three-station mechanism caused by torque overload and improving the stability of the three-station mechanism operation.

[0017] Optionally, the method for determining the stall threshold includes:

[0018] Step 108: Calculate the absolute value of the difference between the rotational torque and the reference torque, and define it as the torque deviation;

[0019] Step 109: When the torque deviation is greater than a preset deviation threshold, extract the rotation speed from the rotation parameters;

[0020] Step 110: Determine the rate of change based on the rotational speed, and determine the switching range based on the torque deviation;

[0021] Step 111: If the rate of change falls within the switching range, determine the switching direction in response to the rate of change;

[0022] Step 112: Determine the switching type based on the load type and switching direction;

[0023] Step 113: Update the baseline torque curve in response to the switching type.

[0024] By adopting the above technical solution, the aging degree of the three-station mechanism can easily cause changes in the motor load, which in turn causes the torque to increase as the aging degree increases. By introducing torque deviation and speed change rate, the switching trend of load type can be accurately identified, thereby dynamically matching the reference torque curve and avoiding false protection or missed protection caused by the outdated reference curve due to load changes. This achieves adaptive matching between load changes and stall threshold.

[0025] Optionally, the method for determining the reference torque curve includes:

[0026] Step 114: Generate the actual torque curve by combining the rotational torque and rotational angle;

[0027] Step 115: Calculate the difference between the actual torque curve and the reference torque curve, and define it as the reference difference curve;

[0028] Step 116: Extract the calibration curve segment from the reference difference curve based on the preset calibration interval;

[0029] Step 117: Determine the calibration coefficient curve in response to the calibration curve segment;

[0030] Step 118: Calculate the product of the calibration coefficient curve and the reference torque curve, and define it as the reference torque curve.

[0031] By adopting the above technical solution, an actual torque curve is generated based on the actual rotational torque and angle during operation. The actual torque curve and the reference torque curve are then compared to select the calibration curve segment where the torque changes. The reference torque curve is then corrected according to the torque change, thereby dynamically correcting the reference difference curve to conform to the actual working conditions and improving the stability of the three-station mechanism.

[0032] Optionally, it also includes an overload prediction method, the overload prediction method comprising:

[0033] Step 200: When the rotational torque is not greater than the stall threshold, determine the torque difference based on the rotational torque, calculate the difference between the stall threshold and the rotational torque, and define it as the overload distance;

[0034] Step 201: Determine the overload cycle by combining the overload distance and torque difference;

[0035] Step 202: If the overload cycle is lower than a preset critical threshold, determine the critical damping by combining the overload cycle and the overload distance;

[0036] Step 203: In response to the generation of the critical damping, a critical adjustment command is sent.

[0037] By adopting the above technical solution, when the rotational torque does not exceed the stall threshold, the collaborative analysis of overload distance and torque difference is introduced to quantitatively predict the overload cycle required for torque overload to occur. This allows for the application of critical damping in advance when the overload cycle is low, thereby providing advance protection for the three-station mechanism and reducing the risk of overload.

[0038] Optionally, the overload prediction method further includes:

[0039] Step 204: If the overload cycle is lower than a preset critical threshold, retrieve the critical torque based on the overload cycle;

[0040] Step 205: Fit a torque growth curve in response to the critical torque;

[0041] Step 206: Read the stall cycle from the torque growth curve based on the stall threshold;

[0042] Step 207: Select the transition damping according to the stall cycle;

[0043] Step 208: In response to the transition damping update critical adjustment command.

[0044] By adopting the above technical solution, the change in torque is generally continuous. When the overload cycle is low, the critical torque within the overload cycle is retrieved and the torque growth curve is fitted, thereby accurately predicting the subsequent change in torque and improving the accuracy of the overload cycle.

[0045] Optionally, the overload prediction method further includes:

[0046] Step 209: When the rotational torque is not greater than the stall threshold, determine the reference difference value based on the reference torque;

[0047] Step 210: Calculate the quotient of the torque difference and the reference difference, and define it as the difference ratio;

[0048] Step 211: Determine the sensitivity coefficient based on the aforementioned difference ratio;

[0049] Step 212: Update the overload cycle based on the aforementioned sensitivity coefficient.

[0050] By adopting the above technical solution, the changing trend of the reference torque curve and the changing trend of the actual torque curve are compared, thereby quantifying the comparison of the changing trends into a difference ratio. The sensitivity coefficient is then adaptively adjusted according to the difference ratio, thereby reducing the sensitivity when the changing trends are similar to avoid false warnings, and increasing the sensitivity when the changing trends are different to ensure timely warnings, thus improving the accuracy of overload prediction.

[0051] Optionally, a jamming handling method is also included, the jamming handling method comprising:

[0052] Step 300: When the rotation speed is less than the preset jamming threshold, determine the yield range based on the rotation angle;

[0053] Step 301: Identify the range amplitude from the yield range;

[0054] Step 302: Determine the upper limit of torque based on the range, and determine the required torque based on the rotational torque;

[0055] Step 303: Determine the yield torque by combining the upper limit of torque and the required torque;

[0056] Step 304: In response to the generated yield torque, a reverse rotation command is sent.

[0057] By adopting the above technical solution, the rotation speed is detected in real time, so that when the rotation speed is too low, it can be determined that the three-station mechanism is stuck. The range of retraction that the moving contact can move without contacting the stationary contact is accurately defined. In combination with the rotation torque, an appropriate retraction torque is selected, thereby driving the motor to reverse to release the stuck state and reduce the impact of the stuck state on the operation of the three-station mechanism.

[0058] Optionally, the jamming handling method further includes:

[0059] Step 305: When the required torque is greater than the torque limit, calculate the difference between the required torque and the torque limit, and define it as the over-limit torque;

[0060] Step 306: Determine the auxiliary damping based on the over-limit torque;

[0061] Step 307: Determine the reverse current according to the auxiliary damping described above;

[0062] Step 308: In response to the reverse current generation, a reverse damping command is sent.

[0063] By adopting the above technical solution, when the clearance range is small, the motor cannot use a large torque to avoid the moving contact and stationary contact causing a change in the working state of the high-voltage switchgear. At this time, the magnetorheological damper applies reverse damping to assist the motor to reverse, thereby reducing the impact of jamming on the operation of the three-station mechanism.

[0064] Optionally, the jamming handling method further includes:

[0065] Step 309: When the required torque is greater than the upper limit of torque, update the rotation speed based on the reverse damping command;

[0066] Step 310: If the rotation speed is less than the preset jamming threshold, determine the number of reverse cycles in response to the reverse damping command;

[0067] Step 311: When the number of reverse cycles exceeds a preset hard threshold, a preset brake command is sent, and the degree of jamming is determined based on the rotational torque;

[0068] Step 312: Generate and display a rotation jamming prompt based on the degree of jamming and the rotation angle.

[0069] By adopting the above technical solution, when jamming occurs, the motor and magnetorheological damper are used to try to release the jamming. If the jamming is not successful after multiple attempts, it is determined that the jamming is relatively serious. At this time, the motor and magnetorheological damper are controlled to lock the brake to avoid damage to the three-station mechanism due to forced reversal, and the staff are notified in time.

[0070] Secondly, this application provides an overload protection system for a three-station mechanism, which adopts the following technical solution:

[0071] A three-station mechanism overload protection system includes:

[0072] The acquisition module is used to collect rotation parameters;

[0073] A memory is used to store the program for any of the above-mentioned overload protection methods for a three-station mechanism;

[0074] The processor is the unit of memory that allows programs to be loaded and executed by the processor.

[0075] By adopting the above technical solution, the rotation parameters of the three-station mechanism are collected in real time. Based on the initial load, the load type is accurately defined and the corresponding reference torque curve is retrieved. Then, the stationary contact of the moving contact is determined by the rotation angle of the moving contact. Then, a suitable stall threshold is matched according to the torque of different stationary contacts, so as to accurately detect the torque overload. The magnetorheological damper is used to apply damping to the torque overload, thereby reducing the damage to the three-station mechanism caused by torque overload and improving the stability of the three-station mechanism operation.

[0076] In summary, this application includes at least one of the following beneficial technical effects:

[0077] The rotation parameters of the three-station mechanism are collected in real time. Based on the initial load, the load type is accurately defined and the corresponding reference torque curve is retrieved. Then, the stationary contact of the moving contact is determined by the rotation angle of the moving contact. Then, a suitable stall threshold is matched according to the torque of different stationary contacts, so as to accurately detect the torque overload. The magnetorheological damper is used to apply damping to the torque overload, thereby reducing the damage to the three-station mechanism caused by torque overload and improving the stability of the three-station mechanism operation.

[0078] The aging degree of the three-station mechanism can easily cause changes in the motor load, which in turn causes the torque to increase as the aging degree increases. By introducing torque deviation and speed change rate, the switching trend of load type can be accurately identified, thereby dynamically matching the reference torque curve and avoiding false protection or missed protection caused by the outdated reference curve due to load changes. This achieves adaptive matching between load changes and stall threshold.

[0079] The actual torque curve is generated based on the actual rotational torque and angle during operation. The actual torque curve is then compared with the reference torque curve to select the calibration curve segment where the torque changes. The reference torque curve is then corrected according to the torque change, thereby dynamically correcting the reference difference curve to conform to the actual working conditions and improving the stability of the three-station mechanism. Attached Figure Description

[0080] Figure 1 This is a flowchart of an overload protection method for a three-station mechanism;

[0081] Figure 2 This is a flowchart of the overload prediction method;

[0082] Figure 3 This is a flowchart of the stuck handling method. Detailed Implementation

[0083] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0084] This application discloses an overload protection method for a three-station mechanism, referring to... Figure 1 An overload protection method for a three-station mechanism, comprising:

[0085] Step 100: Collect rotation parameters.

[0086] Rotation parameters refer to the parameters of the motor-driven three-station mechanism during operation. Rotation parameters include initial load, rotation angle, rotation torque, and rotation speed. These parameters can be retrieved from the motor's control system. The method for acquiring rotation parameters is selected by the operator based on the actual situation and will not be elaborated here.

[0087] Step 101: Retrieve the initial load from the rotation parameters and determine the load type based on the initial load.

[0088] The initial load refers to the load value of the standard motor rotation of the three-position mechanism, i.e., the rated load. The initial load can be obtained from the rotation parameters. The method of obtaining the initial load is selected by the staff according to the actual situation, which will not be elaborated here.

[0089] Load type refers to labels such as light load, rated load, heavy load, etc., used to distinguish loads. The load type corresponding to the initial load can be found from the type correspondence table, which is a data table that records different load types and their corresponding load ranges.

[0090] Step 102: Retrieve the reference torque curve in response to the load type, and extract the rotation angle from the rotation parameters.

[0091] The reference torque curve refers to the curve showing the change in the angle and torque of the motor under a corresponding load type. The reference torque curve corresponding to the load type can be found in the reference correspondence table, which is a data table that records different load types and their corresponding reference torque curves.

[0092] The rotation angle refers to the angle value of the motor output shaft at this time. The rotation angle can be retrieved from the rotation parameters. The method of retrieving the rotation angle is selected by the staff according to the actual situation, and will not be elaborated here.

[0093] Step 103: Based on the rotation angle, retrieve the reference torque from the reference torque curve and determine the correction coefficient according to the initial load.

[0094] The reference torque refers to the torque value of the motor under ideal working conditions, that is, the torque value corresponding to the rotation angle in the reference torque curve. The method for obtaining the reference torque is selected by the staff according to the actual situation, and will not be elaborated here.

[0095] The correction factor is a value used to show the effect of load on torque. The larger the initial load, the greater the torque fluctuation, and therefore the larger the correction factor should be. The correction factor corresponding to the initial load can be found in the correction correspondence table, which is a data table that records different initial loads and their corresponding correction factors.

[0096] Step 104: Determine the stall threshold by combining the reference torque and the correction coefficient, and extract the rotation torque from the rotation parameters.

[0097] The stall threshold is a torque value used to determine whether the motor torque is normal. Generally, the stall threshold is calculated as the product of the reference torque and the correction coefficient. The calculation method for the stall threshold is selected by the staff according to the actual situation, and will not be elaborated here.

[0098] Rotational torque refers to the torque value of the motor at this time. The rotational torque can be retrieved from the rotational parameters. The method for retrieving the rotational torque is selected by the staff according to the actual situation, and will not be elaborated here.

[0099] Step 105: When the rotational torque is greater than the stall threshold, determine the deceleration damping based on the rotational torque.

[0100] A torque exceeding the stall threshold indicates that the motor torque is too high, meaning there is a torque overload. Deceleration damping refers to the minimum damping value required to reduce the motor speed and thus the torque. The corresponding deceleration damping can be found in the damping correspondence table, which records data on different torques and their corresponding deceleration damping.

[0101] Step 106: Determine the deceleration current according to the deceleration damping.

[0102] A magnetorheological damper is a device that adjusts the damping applied to the output shaft of a motor by electronically controlling the magnetic field strength. The selection of a magnetorheological damper is made by the operator based on the actual situation, and will not be elaborated here.

[0103] The deceleration current refers to the input current value required to drive the magnetorheological damper to generate deceleration damping. The deceleration current corresponding to the deceleration damping can be found in the current correspondence table, which is a data table that records different deceleration damping and their corresponding deceleration current.

[0104] Step 107: In response to the deceleration current generation, a damping adjustment command is sent.

[0105] The damping adjustment command is a command to input deceleration current into the magnetorheological damper to generate deceleration damping. The method of generating the damping adjustment command is common knowledge to those in the field and will not be elaborated here.

[0106] The rotation parameters of the three-station mechanism are collected in real time. Based on the initial load, the load type is accurately defined and the corresponding reference torque curve is retrieved. Then, the stationary contact of the moving contact is determined by the rotation angle of the moving contact. The appropriate stall threshold is matched according to the torque of different stationary contacts, so as to accurately detect the torque overload. The magnetorheological damper is used to apply damping to the torque overload, thereby reducing the damage to the three-station mechanism caused by torque overload and improving the stability of the three-station mechanism operation.

[0107] Methods for determining the stall threshold include:

[0108] Step 108: Calculate the absolute value of the difference between the rotational torque and the reference torque, and define it as the torque deviation.

[0109] Torque deviation refers to a numerical value used to show the difference in torque. The calculation method for torque deviation is selected by the staff according to the actual situation, and will not be elaborated here.

[0110] Step 109: When the torque deviation is greater than the preset deviation threshold, extract the rotation speed from the rotation parameters.

[0111] The deviation threshold refers to the minimum torque deviation when the load changes. The deviation threshold is selected by the operator based on the actual situation and will not be elaborated here. A torque deviation greater than the deviation threshold indicates that the load may have changed. Rotation speed refers to the number of revolutions the motor makes per unit time. The rotation speed can be retrieved from the rotation parameters. The method for retrieving the rotation speed is selected by the operator based on the actual situation and will not be elaborated here.

[0112] Step 110: Determine the rate of change based on the rotation speed, and determine the switching range based on the torque deviation.

[0113] The rate of change refers to the change in rotational speed per unit time. It can be determined by taking the rotational speed from a previous unit time as a comparison speed from the rotational parameters, and then using the formula: Rate of change = (Rotational speed - Comparison speed) / Unit time.

[0114] The switching range refers to the range of the rate of change when the load changes. When the load increases, the rotational torque increases with the load, while the rotational speed decreases with the load. The larger the torque deviation, the larger the upper and lower limits of the switching range. The switching range corresponding to the torque deviation can be found in the interval correspondence table, which is a data table that records different torque deviations and their corresponding switching ranges.

[0115] Step 111: If the rate of change falls within the switching range, determine the switching direction in response to the rate of change.

[0116] The rate of change falling into the switching range means that the changes in rotational torque and rotational speed are consistent with the load change. The switching direction refers to the direction of the load change, that is, from heavy load to light load or from light load to heavy load. When the rate of change is positive, it is from heavy load to light load, and when the rate of change is negative, it is from light load to heavy load.

[0117] Step 112: Determine the switching type based on the load type and switching direction.

[0118] Switching type refers to the load type after the load type changes according to the switching direction. For example, when the load type is light load and the switching direction is from light load to heavy load, the switching type is rated. The method for determining the switching type is selected by the staff according to the actual situation, and will not be elaborated here.

[0119] Step 113: Update the baseline torque curve in response to the switching type.

[0120] Changes in the aging degree of a three-station mechanism can easily cause changes in the motor load, resulting in an increase in torque as the aging degree increases. By introducing torque deviation and speed change rate, the switching trend of load type can be accurately identified, thereby dynamically matching the reference torque curve and avoiding false or missed protection caused by the outdated reference curve due to load changes. This achieves adaptive matching between load changes and stall threshold.

[0121] Methods for determining the reference torque curve include:

[0122] Step 114: Generate the actual torque curve by combining the rotational torque and rotational angle.

[0123] The actual torque curve is the curve that shows how the rotational torque changes with the rotation angle. The method for generating the actual torque curve is common knowledge to those in the field and will not be elaborated here.

[0124] Step 115: Calculate the difference between the actual torque curve and the reference torque curve, and define it as the reference difference curve.

[0125] The reference difference curve is a curve used to show how the deviation between the rotational torque and the reference torque changes with the angle value. That is, it is obtained by calculating the difference between the rotational torque and the reference torque corresponding to the same angle value as the reference deviation. The calculation method of the reference difference curve is common knowledge to those in the field and will not be elaborated here.

[0126] Step 116: Extract the calibration curve segment from the benchmark difference curve based on the preset calibration interval.

[0127] The calibration interval refers to the range of reference difference values ​​where the deviation is small and does not require calibration. The calibration interval is selected by the staff based on the actual situation and will not be elaborated here. The calibration curve segment is the curve segment formed by the reference deviation that does not fall into the calibration interval in the reference difference curve. The method for extracting the calibration curve segment is selected by the staff based on the actual situation and will not be elaborated here.

[0128] Step 117: Determine the calibration coefficient curve in response to the calibration curve segment.

[0129] The calibration coefficient curve refers to the numerical value used to show the magnitude of calibration of the calibration curve segment. The larger the reference deviation in the calibration curve segment, the larger the calibration coefficient is used. The calibration coefficient corresponding to the reference deviation can be found from the calibration correspondence table. The curve formed by arranging the calibration coefficients according to the angle is used as the calibration coefficient curve. The calibration coefficient corresponding to the angle value outside the calibration curve segment is 1. Generally, the value corresponding to the same angle in the calibration coefficient curve and the reference torque curve is calculated as the new reference torque curve. The calibration correspondence table is a data table that records different reference deviations and their corresponding calibration coefficients.

[0130] Step 118: Calculate the product of the calibration coefficient curve and the reference torque curve, and define it as the reference torque curve.

[0131] The actual torque curve is generated based on the actual rotational torque and angle during operation. The actual torque curve is then compared with the reference torque curve to select the calibration curve segment where the torque changes. The reference torque curve is then corrected according to the torque change, thereby dynamically correcting the reference difference curve to conform to the actual working conditions and improving the stability of the three-station mechanism.

[0132] Reference Figure 2 Overload prediction methods include:

[0133] Step 200: When the rotational torque is not greater than the stall threshold, determine the torque difference based on the rotational torque, calculate the difference between the stall threshold and the rotational torque, and define it as the overload distance.

[0134] A torque not exceeding the stall threshold indicates that the torque is not overloaded. The torque difference is a value used to show the trend of the rotational torque. It is calculated as the difference between the rotational torque of the current cycle and the rotational torque of the previous cycle. The cycle refers to the time interval between rotational torque updates.

[0135] Overload distance is a numerical value used to show how easy it is for torque to become overloaded. The smaller the overload distance, the easier it is for torque to become overloaded.

[0136] Step 201: Determine the overload cycle by combining the overload distance and torque difference.

[0137] Overload cycle refers to a value used to demonstrate the risk of torque overload, that is, the number of cycles required for the torque to exceed the stall threshold according to the current torque change trend. The overload cycle can be calculated as the quotient of the overload distance and the torque difference.

[0138] Step 202: If the overload period is lower than the preset critical threshold, determine the critical damping by combining the overload period and the overload distance.

[0139] The critical threshold refers to the minimum overload cycle in which the risk of torque overload is relatively high. The critical threshold is selected by the operator based on the actual situation and will not be elaborated here. An overload cycle below the critical threshold indicates a high risk of torque overload, requiring the torque to be reduced in advance to minimize damage to the three-station mechanism. Critical damping refers to the minimum damping value required to reduce torque in advance. The smaller the overload cycle and the smaller the overload distance, the larger the critical damping. The critical damping corresponding to the overload cycle and overload distance can be found in the critical damping correspondence table, which records different overload cycles and overload distances and their corresponding critical damping values.

[0140] Step 203: In response to the generation of the critical damping, a critical adjustment command is sent.

[0141] Critical adjustment command refers to the command that controls the magnetorheological damper to produce critical damping. The method of generating critical adjustment command is common knowledge to those in the field and will not be elaborated here.

[0142] When the rotational torque does not exceed the stall threshold, a collaborative analysis of overload distance and torque difference is introduced to quantitatively predict the overload cycle required for torque overload to occur. This allows for the application of critical damping in advance when the overload cycle is low, thereby providing advance protection for the three-station mechanism and reducing the risk of overload.

[0143] Overload prediction methods also include:

[0144] Step 204: If the overload cycle is lower than a preset critical threshold, retrieve the critical torque based on the overload cycle.

[0145] Critical torque refers to the rotational torque at which the overload period is lower than the corresponding period of the critical threshold. The method for obtaining the critical torque is selected by the staff according to the actual situation, and will not be elaborated here.

[0146] Step 205: Fit a torque growth curve in response to the critical torque.

[0147] The torque growth curve is a curve that predicts the subsequent change of torque based on the fitting of the critical torque. The fitting method of the torque growth curve is common knowledge to those in the field and will not be elaborated here.

[0148] Step 206: Read the stall cycle from the torque growth curve based on the stall threshold.

[0149] The stall cycle is the number of cycles in the torque growth curve when the torque value exceeds the stall threshold. The method for determining the stall cycle is common knowledge in the field and will not be elaborated here.

[0150] Step 207: Select the transition damping according to the stall cycle.

[0151] Transition damping refers to the damping value that smoothly transitions to deceleration damping when torque is overloaded. The smaller the stall period, the greater the transition damping. When the stall period is 0, the transition damping is equal to the deceleration damping corresponding to the stall threshold. The transition damping corresponding to the stall period can be found in the transition correspondence table, which is a data table that records different stall periods and their corresponding transition damping.

[0152] Step 208: In response to the transition damping update critical adjustment command.

[0153] Torque changes are generally continuous. When the overload cycle is low, the critical torque within the overload cycle is retrieved and the torque growth curve is fitted to accurately predict the subsequent changes in torque, thereby improving the accuracy of the overload cycle.

[0154] Overload prediction methods also include:

[0155] Step 209: When the rotational torque is not greater than the stall threshold, determine the reference difference value based on the reference torque.

[0156] The reference difference is a value used to show the changing trend of the reference torque. It can be calculated as the difference between the reference torque of the current cycle and the reference torque of the previous cycle.

[0157] Step 210: Calculate the quotient of the torque difference and the reference difference, and define it as the difference ratio.

[0158] The difference ratio is a numerical value used to show the degree of consistency between the torque difference and the reference difference. The calculation method of the difference ratio is selected by the staff according to the actual situation, and will not be elaborated here.

[0159] Step 211: Determine the sensitivity coefficient based on the difference ratio.

[0160] The sensitivity coefficient is a value used to adjust the sensitivity to torque overload conditions. The closer the difference ratio is to 1, the smaller the sensitivity coefficient. Generally, the quotient of the overload cycle and the sensitivity coefficient is used as the new overload cycle. The sensitivity coefficient corresponding to the difference ratio can be found in the sensitivity correspondence table. The sensitivity correspondence table is a data table that records different difference ratios and their corresponding sensitivity coefficients.

[0161] Step 212: Update the overload cycle based on the aforementioned sensitivity coefficient.

[0162] By comparing the changing trends of the reference torque curve and the actual torque curve, the comparison of the changing trends is quantified as a difference ratio. The sensitivity coefficient is then adaptively adjusted according to the difference ratio. This reduces sensitivity when the changing trends are similar to avoid false alarms, and increases sensitivity when the changing trends are different to ensure timely warnings, thereby improving the accuracy of overload prediction.

[0163] Reference Figure 3 Methods for handling jams include:

[0164] Step 300: When the rotation speed is less than the preset jamming threshold, determine the yield range based on the rotation angle.

[0165] The jamming threshold refers to the maximum rotational speed at which the motor jams. The jamming threshold is selected by the operator based on the actual situation and will not be elaborated upon here. A rotational speed less than the jamming threshold indicates that the motor is jamming. The yield range refers to the area where the motor can reverse direction, that is, the area from the rotation angle to the previous working position. The angle at which the motor can reverse can be used as the yield range. For example, if the rotation angle is 45 degrees and it rotates clockwise, and the stationary contact angles corresponding to the working position, isolation position, and contact position are 0 degrees, 90 degrees, and 180 degrees respectively, then the yield range is from 45 degrees to 90 degrees. The method for determining the yield range is selected by the operator based on the actual situation and will not be elaborated upon here.

[0166] Step 301: Identify the range amplitude from the yield range.

[0167] Range amplitude refers to the numerical value used to show the span of the yield range. The angular span of the yield range can be used as the range amplitude. For example, when the yield range is from 45 degrees to 90 degrees, the range amplitude is 45 degrees. The method for determining the range amplitude is selected by the staff according to the actual situation, and will not be elaborated here.

[0168] Step 302: Determine the upper limit of torque based on the range, and determine the required torque based on the rotational torque.

[0169] The torque limit refers to the maximum reversing torque that can be applied without the moving contact contacting any stationary contact. After applying the reversing torque, the motor is more likely to reverse under the reversing torque. The larger the reversing torque, the larger the angle of motor reversal, the farther the moving contact moves, and the easier it is for the moving contact to contact the stationary contact. The larger the range, the higher the torque limit is used. The torque limit corresponding to the range can be found in the upper limit correspondence table. The upper limit correspondence table is a data table that records different ranges and their corresponding torque limits.

[0170] The required torque refers to the minimum reversing torque required to drive the motor out of the jammed state. The larger the rotational torque, the more severe the jamming situation, and the larger the required torque is required. The required torque corresponding to the rotational torque can be found in the required torque correspondence table, which is a data table that records different rotational torques and their corresponding required torques.

[0171] Step 303: Determine the yield torque by combining the upper limit of torque and the required torque.

[0172] The yield torque refers to the reversal torque value determined by considering both the upper limit of torque and the required torque. That is, when the upper limit of torque is greater than the required torque, the required torque is used as the yield torque, and when the upper limit of torque is not greater than the required torque, the upper limit of torque is used as the yield torque.

[0173] Step 304: In response to the generated yield torque, a reverse rotation command is sent.

[0174] The reverse rotation command is a command that controls the magnetorheological damper to generate a shear torque. The method for generating the reverse rotation command is common knowledge to those in the field and will not be elaborated here.

[0175] The rotation speed is monitored in real time, which can determine that the three-station mechanism is stuck when the rotation speed is too low. The range of retraction that the moving contact can move without contacting the stationary contact is precisely defined. The appropriate retraction torque is selected in combination with the rotation torque, thereby driving the motor to reverse to release the stuck state and reduce the impact of the stuck state on the operation of the three-station mechanism.

[0176] Methods for handling sluggishness also include:

[0177] Step 305: When the required torque is greater than the upper limit of torque, calculate the difference between the required torque and the upper limit of torque, and define it as the over-limit torque.

[0178] A torque requirement greater than the torque limit means that the motor alone cannot generate enough torque to break free from the jamming state. Over-limit torque refers to the torque requirement value that exceeds the torque limit. The calculation method for over-limit torque is selected by the staff based on the actual situation and will not be elaborated here.

[0179] Step 306: Determine the auxiliary damping based on the over-limit torque.

[0180] Auxiliary damping refers to the minimum reverse damping value required to control the magnetorheological damper to reverse the motor. The larger the over-limit torque, the larger the auxiliary damping. The auxiliary damping corresponding to the over-limit torque can be found in the auxiliary correspondence table, which is a data table that records different over-limit torques and their corresponding auxiliary damping.

[0181] Step 307: Determine the reverse current according to the auxiliary damping.

[0182] Reverse current refers to the current value required to control the magnetorheological damper to generate auxiliary damping. The reverse current corresponding to the auxiliary damping can be found in the current correspondence table.

[0183] Step 308: In response to the reverse current generation, a reverse damping command is sent.

[0184] The reverse damping command is a command that inputs a reverse current into the magnetorheological damper to generate auxiliary damping. The method of generating the reverse damping command is common knowledge to those in the field and will not be elaborated here.

[0185] When the clearance range is small, the motor cannot use a large torque to avoid the moving contact and stationary contact causing a change in the working state of the high-voltage switchgear. At this time, reverse damping is applied by a magnetorheological damper to assist the motor to reverse, thereby reducing the impact of jamming on the operation of the three-station mechanism.

[0186] Methods for handling sluggishness also include:

[0187] Step 309: When the required torque is greater than the upper limit of torque, update the rotation speed based on the reverse damping command.

[0188] By using a motor and a magnetorheological damper to attempt to release the jamming, the rotational speed is then measured to determine whether the motor has broken free of the jamming state.

[0189] Step 310: If the rotation speed is less than the preset jamming threshold, determine the number of reverse cycles in response to the reverse damping command.

[0190] The number of reverse attempts refers to the number of times the motor and magnetorheological damper fail to release the jamming. The method for determining the number of reverse attempts is selected by the staff based on the actual situation, and will not be elaborated here.

[0191] Step 311: When the number of reverse cycles exceeds a preset hard threshold, a preset brake command is sent, and the degree of jamming is determined based on the rotational torque.

[0192] The hard threshold refers to the maximum number of reverse attempts to disengage the motor from the jammed state. A value of 3 is typically used as the hard threshold. The hard threshold is selected by the operator based on the actual situation and will not be elaborated upon here. A reverse count exceeding the hard threshold indicates that it is difficult to drive the motor out of the jammed state using the motor and magnetorheological damper in combination, meaning the jamming situation is quite severe. The degree of jamming refers to a numerical value used to represent the severity of the jamming; the greater the rotational torque, the more severe the jamming and the greater the degree of jamming. The degree of jamming corresponding to different rotational torques can be looked up in a degree correspondence table, which records data on different rotational torques and their corresponding degrees of jamming.

[0193] The brake command is a command that controls the motor and magnetorheological damper to lock the brake to prevent the three-position mechanism from rotating. The brake command is selected by the operator according to the actual situation, and will not be elaborated here.

[0194] Step 312: Generate and display a rotation jamming prompt based on the degree of jamming and the rotation angle.

[0195] Rotation jamming prompts are information used to display the degree of jamming and rotation angle to staff so as to prompt them to manually remove the jamming. The method for generating rotation jamming prompts is common knowledge in the field and will not be elaborated here.

[0196] When jamming occurs, attempt to release the jamming by coordinating the motor and magnetorheological damper. If the jamming is deemed to be severe after multiple unsuccessful attempts, the motor and magnetorheological damper are locked in place to prevent damage to the three-station mechanism caused by forced reversal. The staff should be notified immediately.

[0197] Based on the same inventive concept, embodiments of the present invention provide an overload protection system for a three-station mechanism, comprising:

[0198] The acquisition module is used to collect rotation parameters;

[0199] A memory is used to store the program for any of the above-mentioned overload protection methods for a three-station mechanism;

[0200] The processor is the unit of memory that allows programs to be loaded and executed by the processor.

[0201] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0202] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. An overload protection method for a three-station mechanism, characterized in that, include: Step 100: Collect rotation parameters; Step 101: Retrieve the initial load from the rotation parameters and determine the load type based on the initial load; Step 102: Retrieve the reference torque curve in response to the load type, and extract the rotation angle from the rotation parameters; Step 103: Based on the rotation angle, retrieve the reference torque from the reference torque curve and determine the correction coefficient according to the initial load; Step 104: Determine the stall threshold by combining the reference torque and the correction coefficient, and extract the rotational torque from the rotational parameters; Step 105: When the rotational torque is greater than the stall threshold, determine the deceleration damping based on the rotational torque; Step 106: Determine the deceleration current according to the aforementioned deceleration damping; Step 107: In response to the deceleration current generation, a damping adjustment command is sent.

2. The overload protection method for a three-station mechanism according to claim 1, characterized in that, The method for updating the reference torque curve includes: Step 108: Calculate the absolute value of the difference between the rotational torque and the reference torque, and define it as the torque deviation; Step 109: When the torque deviation is greater than a preset deviation threshold, extract the rotation speed from the rotation parameters; Step 110: Determine the rate of change based on the rotational speed, and determine the switching range based on the torque deviation; Step 111: If the rate of change falls within the switching range, determine the switching direction in response to the rate of change; Step 112: Determine the switching type based on the load type and switching direction; Step 113: Update the baseline torque curve in response to the switching type.

3. The overload protection method for a three-station mechanism according to claim 1, characterized in that, The method for determining the reference torque curve includes: Step 114: Generate the actual torque curve by combining the rotational torque and rotational angle; Step 115: Calculate the difference between the actual torque curve and the reference torque curve, and define it as the reference difference curve; Step 116: Extract the calibration curve segment from the reference difference curve based on the preset calibration interval; Step 117: Determine the calibration coefficient curve in response to the calibration curve segment; Step 118: Calculate the product of the calibration coefficient curve and the reference torque curve as the updated reference torque curve.

4. The overload protection method for a three-station mechanism according to claim 1, characterized in that, It also includes an overload prediction method, which includes: Step 200: When the rotational torque is not greater than the stall threshold, determine the torque difference based on the rotational torque, and calculate the difference between the stall threshold and the rotational torque, which is defined as the overload distance. The torque difference is a value used to show the changing trend of the rotational torque, that is, the difference between the rotational torque of the current cycle and the rotational torque of the previous cycle is calculated as the torque difference. Step 201: Determine the overload cycle by combining the overload distance and torque difference; Step 202: If the overload cycle is lower than a preset critical threshold, determine the critical damping by combining the overload cycle and the overload distance; Step 203: In response to the generation of the critical damping, a critical adjustment command is sent.

5. The overload protection method for a three-station mechanism according to claim 4, characterized in that, The overload prediction method further includes: Step 204: If the overload cycle is lower than a preset critical threshold, retrieve the critical torque based on the overload cycle; Step 205: Fit a torque growth curve in response to the critical torque; Step 206: Read the stall cycle from the torque growth curve based on the stall threshold; Step 207: Select the transition damping according to the stall cycle; Step 208: In response to the transition damping update critical adjustment command.

6. The overload protection method for a three-station mechanism according to claim 5, characterized in that, The overload prediction method further includes: Step 209: When the rotational torque is not greater than the stall threshold, determine the reference difference value based on the reference torque. The reference difference value is a value used to show the changing trend of the reference torque, that is, the difference between the reference torque of the current cycle and the reference torque of the previous cycle is calculated as the reference difference value. Step 210: Calculate the quotient of the torque difference and the reference difference, and define it as the difference ratio; Step 211: Determine the sensitivity coefficient based on the aforementioned difference ratio; Step 212: Update the overload cycle based on the aforementioned sensitivity coefficient.

7. The overload protection method for a three-station mechanism according to claim 2, characterized in that, It also includes a jamming handling method, which includes: Step 300: When the rotation speed is less than the preset jamming threshold, determine the yield range based on the rotation angle; Step 301: Identify the range amplitude from the yield range; Step 302: Determine the upper limit of torque based on the range, and determine the required torque based on the rotational torque; Step 303: Determine the yield torque by combining the upper limit of torque and the required torque; Step 304: In response to the generated yield torque, a reverse rotation command is sent.

8. The overload protection method for a three-station mechanism according to claim 7, characterized in that, The jamming handling method also includes: Step 305: When the required torque is greater than the torque limit, calculate the difference between the required torque and the torque limit, and define it as the over-limit torque; Step 306: Determine the auxiliary damping based on the over-limit torque; Step 307: Determine the reverse current according to the auxiliary damping described above; Step 308: In response to the reverse current generation, a reverse damping command is sent.

9. The overload protection method for a three-station mechanism according to claim 8, characterized in that, The jamming handling method also includes: Step 309: When the required torque is greater than the upper limit of torque, update the rotation speed based on the reverse damping command; Step 310: If the rotation speed is less than the preset jamming threshold, determine the number of reverse cycles in response to the reverse damping command; Step 311: When the number of reverse attempts exceeds a preset hard threshold, a preset brake command is sent, and the degree of jamming is determined based on the rotational torque. The hard threshold refers to the maximum number of reverse attempts to disengage from the jam. Step 312: Generate and display a rotation jamming prompt based on the degree of jamming and the rotation angle.

10. An overload protection system for a three-station mechanism, characterized in that, include: The acquisition module is used to collect rotation parameters; A memory for storing a program for an overload protection method for a three-station mechanism as described in any one of claims 1 to 9; The processor is the unit of memory that allows programs to be loaded and executed by the processor.

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