Brake protection method and system for direct-current brushless gear motor

Abstract

The invention relates to the technical field of motor protection, and discloses a brake protection method and system for a direct-current brushless gear motor, and the method comprises the steps: obtaining data; the maximum braking speed serves as the initial braking speed of the motor, the first correction torque of the motor is determined according to the real-time braking torque and a braking torque threshold value, the real-time braking torque is set as the first correction torque, and whether the first correction torque is adjusted or not is judged according to the real-time motor temperature; if adjustment is needed, adjustment is carried out according to the real-time motor temperature, a second correction torque is obtained, and the second correction torque serves as the final brake torque; and the initial braking speed is adjusted until the real-time braking torque of the motor is kept the same as the final braking torque. By means of real-time braking torque adjustment, temperature control, historical data matching and other methods, the effects of stable braking, transmission system protection and motor overheating prevention are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor protection, and in particular to a brake protection method and system for a brushless DC reduction motor. Background Art

[0002] Brushless DC motors (BLDC motors) have the advantages of high efficiency, low noise, long life and maintenance-free. Compared with traditional brushed DC motors, brushless DC motors can provide greater output torque and more precise speed control when used with a reduction mechanism. They are suitable for applications that require stable low-speed operation, such as conveyor belts, CNC equipment and automated production lines.

[0003] However, in actual operation, brushless DC reduction motors face certain challenges when braking. This is especially true when the motor drives a conveyor belt, lifting device, or other load with large inertia and performs active braking. Specifically, if the motor stops instantly during active braking, the load will remain in motion due to its large inertia, causing the transmission shaft to be subjected to a huge impact force, resulting in shaft breakage, gear damage, and even failure of the entire transmission system. Active braking may also cause load failures, such as material accumulation and slippage on the conveyor belt. In addition, the large amount of heat generated by the motor's own friction during active braking will also damage the motor itself.

[0004] Existing motor braking methods often fail to take into account both smooth deceleration and protection of load equipment. Therefore, how to ensure the motor braking effect while avoiding damage to the transmission system has become a key issue in the DC brushless reduction motor braking protection technology. Summary of the invention

[0005] In view of this, the present invention proposes a brake protection method and system for a brushless DC reduction motor, aiming to solve the problem in the current technology that the brushless DC reduction motor itself is easily damaged during active braking.

[0006] On the one hand, the present invention provides a brake protection method for a brushless DC reduction motor, comprising: Obtain the maximum braking rate when the motor load is braking, the braking torque threshold that the motor can withstand, the real-time braking torque and the real-time motor temperature; The maximum braking rate is used as the initial braking rate of the motor, the first correction torque of the motor is determined according to the real-time braking torque and the braking torque threshold, the real-time braking torque is set as the first correction torque, and whether to adjust the first correction torque is determined according to the real-time motor temperature; if the first correction torque does not need to be adjusted, the first correction torque is used as the final braking torque, and if adjustment is required, it is adjusted according to the real-time motor temperature to obtain a second correction torque, and the second correction torque is used as the final braking torque; The initial braking rate is adjusted until the real-time braking torque of the motor remains the same as the final braking torque.

[0007] Further, determining a first correction torque of the motor according to the real-time braking torque and the braking torque threshold comprises: Collect historical characteristic data, the historical characteristic data including: total load mass and historical motor temperature at corresponding time; determine the safety margin torque according to the historical characteristic data, the first correction torque being the difference between the braking torque threshold and the safety margin torque.

[0008] Furthermore, the safety margin torque satisfies the following relationship: ; in, is the historical safety margin torque, is the temperature difference, is the maximum allowable operating temperature of the motor, is the maximum braking rate, is the initial braking rate, is the braking time, is the total mass of the load, is the total mass of the historical maximum load.

[0009] Further, judging whether to adjust the first correction torque according to the real-time motor temperature includes: When the real-time braking torque is set as the first correction torque, start timing and periodically obtain the real-time motor temperature, establish a curve of the real-time motor temperature changing with time, and calculate the slope of the curve; When the real-time motor temperature is greater than or equal to the maximum allowable operating temperature of the motor, the first correction torque is reduced; when the real-time motor temperature is less than the maximum allowable operating temperature of the motor, the real-time slope of the curve is obtained, and when the slope of the curve is less than or equal to zero, the first correction torque is increased, and when the slope of the curve is greater than zero, the first correction torque is not adjusted.

[0010] Further, when reducing the first correction torque, it includes: The temperature difference between the real-time motor temperature and the maximum allowable operating temperature of the motor is calculated, and the time during which the real-time motor temperature is greater than or equal to the maximum allowable operating temperature of the motor is counted, which is recorded as the overload time. The second correction torque is determined according to the temperature difference and the overload time. The second correction torque satisfies the following relationship: ; in, is the second correction moment, is the first correction moment, is the temperature difference, is the overload time, is the maximum allowable operating temperature of the motor, is the overload time, is the preset safety working overload time threshold, is the first attenuation coefficient, The value range of is (0.5, 1].

[0011] Further, when the first correction torque is increased, it includes: The second correction torque is determined according to the absolute value of the temperature difference and the slope of the curve. The second correction torque is determined by the following relationship: ; in, .

[0012] Further, the initial braking rate is adjusted until the real-time braking torque of the motor remains the same as the final braking torque, specifically: Obtain historical braking data, which includes a curve showing changes in historical braking torque and torque unit adjustment over time, compare the real-time braking torque with the historical braking data, intercept the curve when the historical braking torque is equal to the real-time braking torque, stop intercepting and obtain the start and end times of both ends of the intercepted curve when the historical braking torque is the same as the final braking torque; obtain the historical motor temperature corresponding to the historical feature data and the difference in start and end time according to the start and end time, compare the historical motor temperature with the maximum allowable operating temperature of the motor, and the difference between the start and end time and a pre-set time threshold, respectively; when the historical motor temperature is less than or equal to the maximum allowable operating temperature of the motor and the difference between the start and end time is less than or equal to the time threshold, obtain a curve showing changes in torque unit adjustment over time, and adjust the real-time braking torque to be the same as the final braking torque according to the torque unit adjustment; When the difference between the start and end times is greater than the time threshold, it is determined that there is no situation where the historical braking torque or the real-time braking torque is equal.

[0013] Further, the real-time braking torque is compared with the historical braking data. If the historical braking torque does not exist or the real-time braking torque is equal, the difference between the real-time braking torque and the final braking torque and the historical braking data is calculated, and recorded as the first difference and the second difference; Calculate the sum of the first difference and the second difference, when the sum of the first difference and the second difference is the smallest, intercept two corresponding historical braking data on the current curve, obtain corresponding time points of the two historical braking data and calculate the time difference, intercept the curve according to the two historical braking data and obtain the historical motor temperature according to the corresponding time points of the two historical braking data, when the time difference is less than or equal to a preset time threshold and the historical motor temperatures are less than or equal to the maximum allowable operating temperature of the motor, adjust the real-time braking torque to be the same as the final braking torque according to the corresponding torque unit adjustment amount; When the time difference is greater than a preset time threshold, the sum of all the first differences and the second differences is sorted from small to large, and the time difference and the preset time threshold are selected and judged in turn until the time difference is less than or equal to the time threshold.

[0014] Furthermore, when the historical motor temperature is greater than the maximum allowable operating temperature of the motor, the difference between the historical motor temperature and the maximum allowable operating temperature of the motor is calculated and recorded as the historical temperature difference. The torque unit adjustment amount is reduced according to the size of the historical temperature difference, and the reduction amount is linearly proportional to the historical temperature difference.

[0015] Compared with the prior art, the present invention has the following beneficial effects: First, by real-time monitoring of the braking torque, motor temperature, and load status, the braking torque can be dynamically adjusted to ensure that the motor brakes safely within a reasonable range and avoid mechanical failures such as shaft breakage and gear damage caused by excessive braking torque. Secondly, the solution introduces historical feature data, combines the total load mass and historical motor temperature, and calculates the safety margin torque to make the setting of the braking torque more accurate, which not only ensures effective braking, but also prevents the motor from exceeding its bearing capacity, thereby improving safety and stability. In addition, through real-time monitoring and adjustment of the temperature curve, the braking torque can be automatically reduced when the motor temperature is too high to prevent damage to the motor due to overheating. At the same time, the braking torque can be appropriately increased when the temperature is stable or drops to improve braking efficiency.

[0016] The solution also uses historical braking data to optimize the braking rate adjustment process, ensuring that the dynamic changes of the braking torque are more stable and avoiding damage to the motor and transmission system caused by sudden impacts. Intelligent adjustment based on load characteristics and historical data can adapt to different working conditions and improve the accuracy and adaptability of braking control. The optimized calculation of the torque unit adjustment further improves the rationality of the braking rate adjustment, which can achieve precise braking while avoiding the impact of excessive braking on the motor and load.

[0017] On the other hand, the present invention provides a brake protection system for a brushless DC reduction motor, comprising: The acquisition module is configured to obtain the maximum braking rate when the motor load is braking, the braking torque threshold that the motor can withstand, the real-time braking torque and the real-time motor temperature; a first correction module, configured to use the maximum braking rate as an initial braking rate of the motor, determine a first correction torque of the motor according to the real-time braking torque and a braking torque threshold, and set the real-time braking torque as the first correction torque; a second correction module, determining whether to adjust the first correction torque according to the real-time motor temperature; if the first correction torque does not need to be adjusted, using the first correction torque as the final braking torque; if adjustment is required, adjusting according to the real-time motor temperature to obtain a second correction torque, and using the second correction torque as the final braking torque; The initial braking rate is adjusted until the real-time braking torque of the motor remains the same as the final braking torque.

[0018] It can be understood that the above-mentioned brake protection system and method for a brushless DC reduction motor have the same beneficial effects, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 The present invention provides a flow chart of a brake protection method for a brushless DC reduction motor.

[0020] Figure 2 A functional framework diagram of a brake protection system for a brushless DC reduction motor provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The exemplary embodiments disclosed in the present application will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0022] See also Figure 1 As shown, an embodiment of the present invention provides a brake protection method for a brushless DC reduction motor, comprising: Obtain the maximum braking rate when the motor load is braking, the braking torque threshold that the motor can withstand, the real-time braking torque and the real-time motor temperature; The maximum braking rate is used as the initial braking rate of the motor, the first correction torque of the motor is determined according to the real-time braking torque and the braking torque threshold, the real-time braking torque is set as the first correction torque, and it is determined whether to adjust the first correction torque according to the real-time motor temperature; if the first correction torque does not need to be adjusted, the first correction torque is used as the final braking torque, and if adjustment is required, it is adjusted according to the real-time motor temperature to obtain the second correction torque, and the second correction torque is used as the final braking torque; Adjust the initial braking rate until the motor's real-time braking torque remains the same as the final braking torque.

[0023] It should be noted that the electric shock load refers to the equipment or devices driven by the brushless DC reduction motor, such as conveyor belts, elevators, robot joints, etc. The maximum braking rate refers to the maximum deceleration that the motor load can achieve when braking, and the braking rate refers to the deceleration of the motor when braking.

[0024] It is understandable that traditional braking methods usually use a fixed braking torque, but the fixed torque may cause excessive or insufficient braking due to different load sizes, inertia and working conditions. This method obtains the real-time braking torque of the motor and dynamically calculates the first correction torque in combination with the braking torque threshold that the motor can withstand. Then, it is combined with the real-time motor temperature to determine whether it needs to be further adjusted to the second correction torque to ensure that the braking torque is always within a reasonable range, making the braking process smoother, reducing the impact of the impact force on the transmission system, and avoiding damage to mechanical components. When the motor brakes, electromagnetic braking or reverse current braking will generate heat. If not controlled, it may cause the motor temperature to be too high, causing insulation aging, winding damage, and even affecting the life of the motor. This method monitors the motor temperature in real time, establishes a curve of temperature change over time, and calculates the temperature rise rate (curve slope). If the motor temperature exceeds the allowable operating temperature, the braking torque will be reduced, the braking energy consumption will be reduced, and thus the motor will be prevented from overheating and damage; if the temperature rise rate tends to zero, it means that the temperature tends to be stable, and the braking torque is appropriately increased to improve the braking efficiency. This dynamic temperature adjustment mechanism can effectively prevent overheating and improve the reliability of long-term operation of the motor. The rationality of the braking rate is crucial to the safe operation of the motor and its load. If the brake is too fast, the transmission parts will be severely impacted, resulting in damage to the bearings and gears; if the brake is too slow, it may affect the operating efficiency and even cause the load to overflow or accumulate. This method first sets the initial braking rate and continuously adjusts it during the braking process to keep the real-time braking torque consistent with the final braking torque. In this way, while ensuring the braking effect, the impact load can be avoided and the safety of the transmission system can be improved. Since this method can intelligently adjust the braking torque and braking rate to avoid excessive impact loads during braking, and prevent the motor from overheating and causing performance degradation, it can effectively reduce the wear of the motor and mechanical structure. In the long run, this intelligent braking strategy can reduce the failure rate of the motor and its transmission system, reduce maintenance costs, extend the service life of the motor, and improve the reliability of the overall equipment. Since this method fully considers factors such as real-time motor temperature, braking torque, historical operating data, and can dynamically adjust the braking parameters, it can maintain a better braking effect under different load conditions, ambient temperatures and operating conditions. For example, under high load conditions, the braking torque will be automatically reduced to protect the transmission structure, while under light load conditions, the braking torque can be appropriately increased to improve braking efficiency. This intelligent adjustment method makes the method widely applicable and can meet the needs of various industrial applications.

[0025] In some embodiments of the present application, determining the first correction torque of the motor according to the real-time braking torque and the braking torque threshold includes: Collect historical characteristic data, including: total load mass and historical motor temperature at the corresponding time; determine the safety margin torque based on the historical characteristic data, and the first correction torque is the difference between the braking torque threshold and the safety margin torque. The safety margin torque satisfies the following relationship: ; in, is the historical safety margin torque, is the temperature difference, is the maximum allowable operating temperature of the motor, is the maximum braking rate, is the initial braking rate, is the braking time, is the total mass of the load, is the total mass of the historical maximum load.

[0026] It should be noted that by collecting historical characteristic data (total load mass and historical motor temperature), the current braking torque can be optimized according to past operating conditions, avoiding the use of excessive or too small braking torque, improving the accuracy of braking control, and making the braking process smoother. The total load mass directly affects the braking process, especially in scenarios with large load changes such as conveyor belts or lifting equipment. This method calculates the change in the current total load mass relative to the historical maximum load, so that the braking parameters can be dynamically adjusted to ensure that the best braking effect can be obtained under different load conditions, avoiding safety problems caused by insufficient braking torque or overload. Directly using the braking torque threshold may cause damage to the motor or transmission mechanism in extreme cases (such as high temperature, overload). Therefore, this method introduces a safety margin torque to ensure that the torque during braking does not directly reach the limit value of the motor, thereby reducing the impact force on mechanical components and improving reliability. Due to the heat generated during the braking process, the motor temperature may rise to a dangerous range. This method determines whether the motor will overheat due to braking by calculating the temperature difference and the maximum allowable temperature, and dynamically adjusts the braking torque to prevent the temperature from exceeding the safe range, reduce insulation aging and efficiency reduction caused by overheating, and thus extend the service life of the motor. Variables such as the maximum braking rate, initial braking rate, and braking time are introduced into the formula, so that the braking process can be adaptively adjusted according to the current operating status. This ensures that the motor completes braking in the shortest possible time without causing excessive mechanical shock, thereby improving the overall braking efficiency. Since inertial loads may cause mechanical shocks during braking, this method calculates the ratio of the motor load to the historical maximum load, so that the braking torque can change smoothly under large load conditions, avoiding problems such as equipment damage or material sliding caused by excessive braking, and improving the stability and safety of braking.

[0027] In some embodiments of the present application, judging whether to adjust the first correction torque according to the real-time motor temperature includes: When the real-time braking torque is set as the first correction torque, the timing is started and the real-time motor temperature is periodically obtained, a curve of the real-time motor temperature changing with time is established, and the slope of the curve is calculated; When the real-time motor temperature is greater than or equal to the maximum allowable operating temperature of the motor, the first correction torque is reduced; when the real-time motor temperature is less than the maximum allowable operating temperature of the motor, the real-time curve slope is obtained, and when the curve slope is less than or equal to zero, the first correction torque is increased, and when the curve slope is greater than zero, the first correction torque is not adjusted.

[0028] It should be noted that by real-time monitoring of the motor temperature and reducing the braking torque when the temperature reaches the maximum allowable operating temperature, the motor can be effectively prevented from being damaged due to overheating, thereby improving safety and reliability. The temperature change curve and slope calculation are used to make the adjustment of the braking torque more accurate. When the temperature rises slowly or decreases (curve slope ≤ 0), the braking torque is increased to improve the braking efficiency and shorten the braking time; when the temperature rises rapidly (curve slope > 0), the braking torque is kept unchanged to avoid temperature runaway. While ensuring the braking effect, the braking torque is reasonably controlled to make the motor operate within the operating temperature range, avoiding problems such as aging of insulation materials and overheating of coils caused by long-term high temperature, thereby extending the service life of the motor. This method adjusts the braking torque based on dynamic feedback of temperature, so that the braking strategy can be automatically optimized according to the actual working conditions without manual intervention, improving the level of intelligence and making it suitable for different loads and environmental conditions.

[0029] In some embodiments of the present application, when reducing the first correction torque, it includes: The temperature difference between the real-time motor temperature and the maximum allowable operating temperature of the motor is calculated, and the time during which the real-time motor temperature is greater than or equal to the maximum allowable operating temperature of the motor is counted, which is recorded as the overload time. The second correction torque is determined according to the temperature difference and the overload time. The second correction torque satisfies the following relationship: ; in, is the second correction moment, is the first correction moment, is the temperature difference, is the overload time, is the maximum allowable operating temperature of the motor, is the overload time, is the preset safety working overload time threshold, is the first attenuation coefficient, The value range of is (0.5, 1].

[0030] It should be noted that by calculating the temperature difference between the actual motor temperature and the maximum allowable operating temperature (i.e., the temperature difference), and counting the duration of the motor temperature exceeding the limit (overload time), the current overload state of the motor can be accurately evaluated. When the motor temperature exceeds the allowable range and lasts for a long time, the braking torque is gradually reduced to avoid damage to the motor due to overload. The temperature difference is taken into account in the formula. Overload time The influence of the overload makes the adjustment of the braking torque not only depend on the current temperature, but also take into account the duration of the overload. In this way, a high braking torque can be maintained in the case of a short-term overtemperature, and the braking torque can be reduced in the case of a long-term overtemperature to ensure stable operation. The first attenuation coefficient is used , so that the braking torque gradually decreases with the increase of overload time, rather than abrupt adjustment, thereby reducing impact and avoiding the normal operation of the motor affected by excessive adjustment of the braking torque. A safety overload time threshold is set. As the attenuation coefficient is adjustable, it can adapt to different types of load conditions and improve the adaptability and intelligence level of the brake protection strategy.

[0031] In some embodiments of the present application, when the first correction torque is increased, it includes: The second correction torque is determined according to the absolute value of the temperature difference and the slope of the curve. The second correction torque is determined by the following relationship: ; in, is the second correction moment, is the first correction moment, is the temperature difference, is the second attenuation coefficient, and the value range of β is (0.5, 1], is the slope of the curve.

[0032] It should be noted that by introducing the temperature difference And the exponential correction model is used to adjust the braking torque in real time. When the motor temperature is lower than the maximum allowable temperature and the cooling trend is obvious, the braking torque can be appropriately increased to improve the braking effect, while ensuring that the motor will not cause unstable braking due to insufficient braking torque. The second attenuation coefficient is used , ensuring that the change in braking torque will not increase suddenly, but will be adjusted smoothly with the change in temperature difference, avoiding abrupt torque increase during braking and affecting stability. This formula calculates the difference between the maximum allowable temperature and the current temperature, rationally utilizes the temperature margin of the motor, and maximizes the braking torque while ensuring safety, thereby improving braking efficiency. By adjusting the attenuation coefficient, it can adapt to different load conditions, making the adjustment of the braking torque more flexible, so that it is suitable for different types of loads and operating environments, and improving the level of intelligence.

[0033] In addition, the first attenuation coefficient is determined by the following method: multiple levels of preset overload time are set, and the preset overload times are sorted in order from small to large according to the numerical value. Every two adjacent preset overload times form an interval, and a first attenuation coefficient value is assigned to each interval, and the value range is (0.5, 1]. According to the size of the overload time, it is included in the corresponding interval, so as to obtain the value of the first attenuation coefficient corresponding to the interval. Similarly, according to setting multiple preset temperature differences, a value of the first attenuation coefficient is obtained again. Finally, the average of the two values ​​is taken as the final first attenuation coefficient.

[0034] The second attenuation coefficient is determined in the same way as the first attenuation coefficient. The difference is that the second attenuation coefficient is determined by setting the absolute values ​​of multiple temperature differences and preset values ​​of the curve slope, and then defining intervals to obtain two values ​​of the second attenuation coefficients. Their average value is calculated and used as the final second attenuation coefficient.

[0035] In some embodiments of the present application, the initial braking rate is adjusted until the real-time braking torque of the motor remains the same as the final braking torque, specifically: Obtain historical braking data, which includes a curve showing changes in historical braking torque and torque unit adjustment over time, compare the real-time braking torque with the historical braking data, intercept the curve when the historical braking torque is equal to the real-time braking torque, and stop intercepting when the historical braking torque is the same as the final braking torque, and obtain the start and end times of both ends of the intercepted curve; obtain the historical motor temperature and the difference in start and end time in the corresponding historical feature data according to the start and end time, compare the historical motor temperature with the maximum allowable operating temperature of the motor, and the difference in start and end time with a pre-set time threshold, respectively; when the historical motor temperature is less than or equal to the maximum allowable operating temperature of the motor and the difference in start and end time is less than or equal to the time threshold, obtain a curve showing changes in torque unit adjustment over time, and adjust the real-time braking torque to be the same as the final braking torque according to the torque unit adjustment; When the difference between the start and end times is greater than the time threshold, it is determined that there is no historical braking torque or the real-time braking torque is equal.

[0036] It should be noted that the historical braking data with the same total mass as the current motor load is selected. The torque unit adjustment amount is the torque adjustment amount per unit time.

[0037] It is understandable that by comparing the real-time braking torque with the historical braking data, the braking curve closest to the current situation is selected, and the initial braking rate is adjusted to make the adjustment more accurate, avoid excessive or insufficient adjustment, and improve the braking stability. The appropriate braking torque adjustment curve is directly extracted from the historical data, rather than relying entirely on real-time calculation, which reduces the calculation complexity, improves the response speed, and makes the braking adjustment more efficient. When adjusting the braking rate, ensure that the historical motor temperature does not exceed the maximum allowable operating temperature of the motor, and check whether the time difference is within a reasonable range, so as to prevent the motor from overheating and improve the safety and reliability of the braking process. Through the curve of the torque unit adjustment amount changing with time, the real-time braking torque is gradually adjusted to keep it consistent with the final braking torque, ensuring a smooth braking process, avoiding abrupt changes, and improving braking accuracy and comfort. Select historical braking data with the same total mass as the current motor load to ensure that the adjustment strategy is optimized for specific load conditions, so that the method can adapt to different load conditions and improve versatility and adaptability.

[0038] In some embodiments of the present application, the real-time braking torque is compared with the historical braking data. If there is no historical braking torque or the real-time braking torque is equal, the difference between the real-time braking torque and the final braking torque and the historical braking data is calculated, and recorded as the first difference and the second difference; Calculate the sum of the first difference and the second difference, when the sum of the first difference and the second difference is the smallest, intercept the two corresponding historical braking data on the current curve, obtain the corresponding time points of the two historical braking data and calculate the time difference, intercept the curve according to the two historical braking data and obtain the historical motor temperature according to the corresponding time points of the two historical braking data, when the time difference is less than or equal to the preset time threshold and the historical motor temperatures are less than or equal to the maximum allowable operating temperature of the motor, adjust the real-time braking torque to be the same as the final braking torque according to the corresponding torque unit adjustment amount; When the time difference is greater than a preset time threshold, the sum of all first differences and second differences is sorted from small to large, and the time difference and the preset time threshold are selected and judged in turn until the time difference is less than or equal to the time threshold.

[0039] It should be noted that by comparing the real-time braking torque with the historical braking data, the current braking torque can be adjusted according to the past braking conditions. More accurate braking decisions can be made under similar working conditions to avoid inappropriate braking caused by sudden or uncertain current conditions. The difference between the real-time braking torque and the final braking torque (the first difference and the second difference) is calculated, and the historical data with the smallest difference is selected for reference to ensure that the adjusted braking torque is close to the optimal braking value in historical experience. When selecting historical braking data, whether to adjust the braking torque is determined based on the time difference and the motor temperature. By setting a time threshold, it is ensured that the time difference between the selected historical data and the current operation is within a reasonable range to avoid data with too long a time difference affecting the braking effect. In addition, the historical motor temperature will be checked to ensure that the historical motor temperature does not exceed the maximum allowable operating temperature of the motor to avoid motor damage due to overheating. If these conditions are met, the braking torque will be adjusted to make the motor braking process smoother and safer when the load is heavy. Based on the comparison of historical data and real-time data, the real-time braking torque can be dynamically adjusted to gradually approach the final braking torque. This adjustment process ensures a smoother transition of the brakes and avoids sudden and drastic changes that adversely affect the motor and drive system. By comparing the difference and minimizing the difference, sudden and drastic brake torque adjustments can be avoided, thereby reducing the impact on the motor and drive system and maintaining stability and long life. By adaptively selecting historical data to adjust the current brake torque, the brake control not only depends on the current state, but also predicts and optimizes the braking effect based on historical performance. This method improves the intelligence and adaptability of the brake control and can cope with changes under different working conditions. The method is not only based on historical data, but also monitors and adjusts the brake torque in real time to ensure the best braking effect under the current operating conditions. This dynamic adjustment method makes the brake more flexible and can adapt to different load and temperature conditions. By comprehensively considering historical brake data and current real-time data, over-braking is avoided. In particular, when the load changes or the motor temperature rises, the brake torque can be adjusted more flexibly to avoid damage to the motor due to excessive braking. By selecting historical data based on the minimum difference, the brake torque can be accurately adjusted to avoid excessive deviations and ensure a more accurate and smooth braking process.

[0040] In some embodiments of the present application, when the historical motor temperature is greater than the maximum allowable operating temperature of the motor, the difference between the historical motor temperature and the maximum allowable operating temperature of the motor is calculated and recorded as the historical temperature difference. The torque unit adjustment amount is reduced according to the size of the historical temperature difference, and the reduction amount is linearly proportional to the historical temperature difference.

[0041] It should be noted that the motor may generate too much heat during operation due to excessive braking or continuous operation, resulting in an increase in temperature. When the temperature is too high, the working efficiency of the motor will decrease, and it may even cause damage. Therefore, it is necessary to monitor the temperature of the motor in real time and adjust the braking torque according to the temperature to avoid overheating. If the historical motor temperature is greater than the maximum allowable operating temperature of the motor, the historical temperature difference (that is, the difference between the historical motor temperature and the maximum allowable operating temperature of the motor) is calculated. This temperature difference reflects the current overheating degree of the motor. The temperature difference can be used to evaluate whether the motor is in an overloaded or overheated state. The torque unit adjustment amount is linearly proportional to the historical temperature difference. In other words, the greater the difference between the historical motor temperature and the maximum operating temperature, the greater the torque unit adjustment amount, thereby reducing the braking torque. In this way, the system can actively reduce the braking force when the motor temperature is too high to avoid further heat generation. This down-regulation mechanism can help protect the motor from overheating damage and avoid motor performance degradation, insulation damage or other faults caused by excessive temperature. When the motor temperature is too high, if excessive braking torque continues to be applied, the motor temperature will further rise, increasing the risk of motor damage. By reducing the braking torque, the system can actively reduce the burden when the motor overheats, thereby avoiding permanent damage to the motor due to overheating.

[0042] See also Figure 2 As shown, an embodiment of the present invention provides a brake protection system for a brushless DC reduction motor, comprising: The acquisition module is configured to obtain the maximum braking rate when the motor load is braking, the braking torque threshold that the motor can withstand, the real-time braking torque and the real-time motor temperature; A first correction module is configured to use the maximum braking rate as the initial braking rate of the motor, determine a first correction torque of the motor according to the real-time braking torque and the braking torque threshold, and set the real-time braking torque as the first correction torque; The second correction module determines whether to adjust the first correction torque according to the real-time motor temperature; if the first correction torque does not need to be adjusted, the first correction torque is used as the final braking torque; if adjustment is required, the second correction torque is adjusted according to the real-time motor temperature to obtain the second correction torque, and the second correction torque is used as the final braking torque; Adjust the initial braking rate until the motor's real-time braking torque remains the same as the final braking torque.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A brake protection method for a brushless DC reduction motor, characterized in that: include: Obtain the maximum braking rate when the motor load is braking, the braking torque threshold that the motor can withstand, the real-time braking torque and the real-time motor temperature; Using the maximum braking rate as the initial braking rate of the motor, determining a first correction torque of the motor according to the real-time braking torque and a braking torque threshold, setting the real-time braking torque as the first correction torque, and determining whether to adjust the first correction torque according to the real-time motor temperature; If the first correction torque does not need to be adjusted, the first correction torque is used as the final braking torque; if adjustment is required, the second correction torque is adjusted according to the real-time motor temperature to obtain the second correction torque, and the second correction torque is used as the final braking torque; The initial braking rate is adjusted until the real-time braking torque of the motor remains the same as the final braking torque.

2. The brake protection method for a brushless DC motor according to claim 1, characterized in that: Determining a first correction torque of the motor according to the real-time braking torque and the braking torque threshold includes: Collect historical characteristic data, the historical characteristic data including: total load mass and historical motor temperature at corresponding time; determine the safety margin torque according to the historical characteristic data, the first correction torque being the difference between the braking torque threshold and the safety margin torque.

3. The brake protection method for a brushless DC motor according to claim 2, characterized in that: The safety margin torque satisfies the following relationship: ； in, is the historical safety margin torque, is the temperature difference, is the maximum allowable operating temperature of the motor, is the maximum braking rate, is the initial braking rate, is the braking time, is the total mass of the load, is the total mass of the maximum load in history.

4. The brake protection method for a brushless DC reduction motor according to claim 3, characterized in that: Determining whether to adjust the first correction torque according to the real-time motor temperature includes: When the real-time braking torque is set as the first correction torque, start timing and periodically obtain the real-time motor temperature, establish a curve of the real-time motor temperature changing with time, and calculate the slope of the curve; When the real-time motor temperature is greater than or equal to the maximum allowable operating temperature of the motor, the first correction torque is reduced; when the real-time motor temperature is less than the maximum allowable operating temperature of the motor, the real-time slope of the curve is obtained, and when the slope of the curve is less than or equal to zero, the first correction torque is increased, and when the slope of the curve is greater than zero, the first correction torque is not adjusted.

5. The brake protection method for a brushless DC motor according to claim 4, characterized in that: When reducing the first correction torque, it includes: The temperature difference between the real-time motor temperature and the maximum allowable operating temperature of the motor is calculated, and the time during which the real-time motor temperature is greater than or equal to the maximum allowable operating temperature of the motor is counted, which is recorded as the overload time. The second correction torque is determined according to the temperature difference and the overload time. The second correction torque satisfies the following relationship: ； in, is the second correction moment, is the first correction moment, is the temperature difference, is the overload time, is the maximum allowable operating temperature of the motor, is the overload time, is the preset safety working overload time threshold, is the first attenuation coefficient, The value range of is (0.5, 1].

6. The brake protection method for a brushless DC reduction motor according to claim 5, characterized in that: When the first correction torque is added, it includes: The second correction torque is determined according to the absolute value of the temperature difference and the slope of the curve. The second correction torque is determined by the following relationship: ； in, is the second correction moment, is the first correction moment, is the temperature difference, is the second attenuation coefficient, is the slope of the curve.

7. The brake protection method for a brushless DC reduction motor according to claim 6, characterized in that: The initial braking rate is adjusted until the real-time braking torque of the motor remains the same as the final braking torque, specifically: Obtain historical braking data, including a curve showing changes in historical braking torque and torque unit adjustment over time, compare the real-time braking torque with the historical braking data, intercept the curve when the historical braking torque is equal to the real-time braking torque, stop intercepting when the historical braking torque is the same as the final braking torque, and obtain the start and end times of both ends of the intercepted curve; According to the start and end time, the historical motor temperature and the difference between the start and end time in the historical characteristic data corresponding to the historical characteristic data are obtained, and the historical motor temperature is compared with the maximum allowable working temperature of the motor, and the difference between the start and end time is compared with a preset time threshold. When the historical motor temperature is less than or equal to the maximum allowable working temperature of the motor and the difference between the start and end time is less than or equal to the time threshold, a curve of the change of the torque unit adjustment amount over time is obtained, and the real-time braking torque is adjusted to be the same as the final braking torque according to the torque unit adjustment amount; When the difference between the start and end times is greater than the time threshold, it is determined that there is no situation where the historical braking torque or the real-time braking torque is equal.

8. The brake protection method for a brushless DC motor according to claim 7, characterized in that: The real-time braking torque is compared with the historical braking data. If the historical braking torque does not exist or the real-time braking torque is equal, the difference between the real-time braking torque and the final braking torque and the historical braking data is calculated, and recorded as the first difference and the second difference; Calculate the sum of the first difference and the second difference, when the sum of the first difference and the second difference is the smallest, intercept two corresponding historical braking data on the current curve, obtain corresponding time points of the two historical braking data and calculate the time difference, intercept the curve according to the two historical braking data and obtain the historical motor temperature according to the corresponding time points of the two historical braking data, when the time difference is less than or equal to a preset time threshold and the historical motor temperatures are less than or equal to the maximum allowable operating temperature of the motor, adjust the real-time braking torque to be the same as the final braking torque according to the corresponding torque unit adjustment amount; When the time difference is greater than a preset time threshold, the sum of all the first differences and the second differences is sorted from small to large, and the time difference and the preset time threshold are selected and judged in turn until the time difference is less than or equal to the time threshold.

9. The brake protection method for a brushless DC reduction motor according to claim 8, characterized in that: When the historical motor temperature is greater than the maximum allowable operating temperature of the motor, the difference between the historical motor temperature and the maximum allowable operating temperature of the motor is calculated and recorded as the historical temperature difference. The torque unit adjustment amount is reduced according to the size of the historical temperature difference, and the reduction amount is linearly proportional to the historical temperature difference.

10. A brake protection system for a brushless DC reduction motor, used to implement the brake protection method for a brushless DC reduction motor according to any one of claims 1 to 9, characterized in that: include: The acquisition module is configured to obtain the maximum braking rate when the motor load is braking, the braking torque threshold that the motor can withstand, the real-time braking torque and the real-time motor temperature; a first correction module, configured to use the maximum braking rate as an initial braking rate of the motor, determine a first correction torque of the motor according to the real-time braking torque and a braking torque threshold, and set the real-time braking torque as the first correction torque; a second correction module, determining whether to adjust the first correction torque according to the real-time motor temperature; If the first correction torque does not need to be adjusted, the first correction torque is used as the final braking torque; if adjustment is required, the second correction torque is adjusted according to the real-time motor temperature to obtain the second correction torque, and the second correction torque is used as the final braking torque; The initial braking rate is adjusted until the real-time braking torque of the motor remains the same as the final braking torque.

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