A braking protection method and system for a DC brushless reduction motor

Abstract

The present invention relates to the technical field of motor protection, and discloses a braking protection method and system for a DC brushless reduction motor. The method includes: obtaining data; taking the maximum braking rate as the initial braking rate of the motor, determining the first correction torque of the motor according to the real-time braking torque and the braking torque threshold, setting the real-time braking torque as the first correction torque, and judging whether to adjust the first correction torque according to the real-time motor temperature; if adjustment is required, adjusting according to the real-time motor temperature to obtain the second correction torque, and taking the second correction torque as the final braking torque; adjusting the initial braking rate until the real-time braking torque of the motor remains the same as the final braking torque. The present invention realizes the effects of smooth braking, protecting the transmission system, and avoiding overheating of the motor through methods such as real-time braking torque adjustment, temperature control, and historical data matching.

Description

Technical Field

[0001] The present invention relates to the technical field of motor protection, and more particularly, to a braking protection method and system for a DC brushless geared motor. Background Art

[0002] Due to its advantages such as high efficiency, low noise, long life, and maintenance-free operation, the DC brushless geared motor (BLDC geared motor) can provide greater output torque and more precise speed control when used in conjunction with a reduction mechanism compared to traditional DC brushed motors. It is suitable for application scenarios that require stable low-speed operation, such as conveyor belts, numerical control equipment, and automated production lines.

[0003] However, during actual operation, the DC brushless geared motor faces certain challenges during braking. Especially in scenarios where the motor drives inertial loads such as conveyor belts and lifting devices and performs active braking. Specifically, when the motor stops rotating instantaneously during active braking, the load will maintain its motion state due to its large inertia. At this time, the transmission shaft will bear a huge impact force, resulting in shaft fracture, gear damage, and even failure of the entire transmission system. Active braking may also cause load failures, such as material accumulation and slipping on the conveyor belt. In addition, a 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 cannot balance smooth deceleration and protection of load equipment. Therefore, how to avoid damage to the transmission system while ensuring the braking effect of the motor has become a key issue in the braking protection technology of DC brushless geared motors. Summary of the Invention

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

[0006] On the one hand, a braking protection method for a DC brushless geared motor proposed by the present invention includes:

[0007] Obtaining the maximum braking rate during braking of the motor load, the braking torque threshold that the motor can withstand, the real-time braking torque, and the real-time motor temperature;

[0008] Take the maximum braking rate as the initial braking rate of the motor, determine the first correction torque of the motor according to the real-time braking torque and the braking torque threshold, set the real-time braking torque as the first correction torque, and determine whether to adjust the first correction torque according to the real-time motor temperature; if there is no need to adjust the first correction torque, take the first correction torque as the final braking torque, if adjustment is required, adjust according to the real-time motor temperature to obtain the second correction torque, and take the second correction torque as the final braking torque;

[0009] Adjust the initial braking rate until the real-time braking torque of the motor remains the same as the final braking torque.

[0010] Further, determining the first correction torque of the motor according to the real-time braking torque and the braking torque threshold includes:

[0011] Collect historical feature data, where the historical feature data includes: the total load mass and the historical motor temperature at the corresponding time; determine the safety margin torque according to the historical feature data, and the first correction torque is the difference between the braking torque threshold and the safety margin torque.

[0012] Further, the safety margin torque satisfies the following relationship:

[0013] ;

[0014] Wherein, 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 load mass, is the historical maximum total load mass.

[0015] Further, determining whether to adjust the first correction torque according to the real-time motor temperature includes:

[0016] When setting the real-time braking torque 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 curve slope;

[0017] When the real-time motor temperature is greater than or equal to the maximum allowable operating temperature of the motor, reduce the first correction torque; when the real-time motor temperature is less than the maximum allowable operating temperature of the motor, obtain the real-time curve slope. When the curve slope is less than or equal to zero, increase the first correction torque. When the curve slope is greater than zero, do not adjust the first correction torque.

[0018] Further, when reducing the first correction torque, it includes:

[0019] Calculate the temperature difference between the real-time motor temperature and the maximum allowable operating temperature of the motor and count the duration during which the real-time motor temperature is greater than or equal to the maximum allowable operating temperature of the motor, denoted as the overload time. Determine the second correction torque according to the temperature difference and the overload time. The second correction torque satisfies the following relationship:

[0020] ;

[0021] Where, is the second correction torque, is the first correction torque, 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 operating overload time threshold, is the first attenuation coefficient, The value range of is (0.5, 1].

[0022] Further, when increasing the first correction torque, it includes:

[0023] Determine the second correction torque according to the absolute value of the temperature difference and the curve slope. The second correction torque is determined by the following relationship:

[0024] ;

[0025] Where, .

[0026] Further, adjust the initial braking rate until the real-time braking torque of the motor remains the same as the final braking torque. Specifically:

[0027] Obtain historical braking data, which includes curves of historical braking torque and torque unit adjustment amount varying with time. Compare the real-time braking torque with the historical braking data. When there is an equality between the historical braking torque and the real-time braking torque, intercept the curve until the historical braking torque is the same as the final braking torque, and then stop intercepting and obtain the start and end times at both ends of the intercepted curve. Obtain the historical motor temperature in the corresponding historical feature data and the difference between the start and end times according to the start and end times. Compare the historical motor temperature with the maximum allowable operating temperature of the motor and the difference between the start and end times with a preset 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 times is less than or equal to the time threshold, obtain the curve of the torque unit adjustment amount varying with time, and adjust the real-time braking torque to be the same as the final braking torque according to the torque unit adjustment amount.

[0028] When the difference between the start and end times is greater than the time threshold, it is determined that there is no equality between the historical braking torque and the real-time braking torque.

[0029] Further, compare the real-time braking torque with the historical braking data. If there is no equality between the historical braking torque and the real-time braking torque, calculate the differences between the real-time braking torque and the final braking torque and the historical braking data respectively, denoted as the first difference and the second difference.

[0030] 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 corresponding two 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 temperature is 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.

[0031] When the time difference is greater than the preset time threshold, sort all the sums of the first difference and the second difference from small to large, select them in turn and judge the size relationship between the time difference and the preset time threshold until the time difference is less than or equal to the time threshold.

[0032] Further, when the historical motor temperature is greater than the maximum allowable operating temperature of the motor, calculate the difference between the historical motor temperature and the maximum allowable operating temperature of the motor, denoted as the historical temperature difference. Downwardly adjust the torque unit adjustment amount according to the size of the historical temperature difference, and the downward adjustment amount is in a linear proportional relationship with the historical temperature difference.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] Firstly, by real-time monitoring of the braking torque, motor temperature and load status, dynamic adjustment of the braking torque is achieved to ensure safe braking of the motor within a reasonable range, avoiding mechanical failures such as shaft fractures and gear damage caused by excessive braking torque. Secondly, the scheme introduces historical feature data, combines the total load mass and historical motor temperature to calculate the safety margin torque, making the setting of the braking torque more accurate, ensuring effective braking while preventing exceeding the motor's bearing capacity, and improving safety and stability. In addition, through the monitoring and adjustment of the real-time 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, and the braking torque can be appropriately increased when the temperature is stable or decreasing to improve the braking efficiency.

[0035] The scheme also uses historical braking data to optimize the braking rate adjustment process, ensuring that the dynamic change of the braking torque is more stable and avoiding damage to the motor and transmission system caused by sudden impacts. The intelligent adjustment based on the load characteristics and historical data can adapt to different working conditions, improving the accuracy and adaptability of braking control. The optimized calculation of the torque unit adjustment amount further improves the rationality of the braking rate adjustment, enabling accurate braking while avoiding the impact of over-braking on the motor and load.

[0036] On the other hand, a braking protection system for a DC brushless reduction motor proposed by the present invention includes:

[0037] An acquisition module configured to obtain the maximum braking rate when the motor load is braked, the braking torque threshold that the motor can withstand, the real-time braking torque and the real-time motor temperature;

[0038] A first correction module configured to use the maximum braking rate as the initial braking rate of the motor, determine the 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;

[0039] A 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, 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;

[0040] Adjust the initial braking rate until the real-time braking torque of the motor remains the same as the final braking torque.

[0041] It is understandable that the above braking protection system and method for a DC brushless geared motor have the same beneficial effects, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0043] Figure 1 is a flowchart of the braking protection method for a DC brushless geared motor provided by an embodiment of the present invention.

[0044] Figure 2 is a functional framework diagram of the braking protection system for a DC brushless geared motor provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The exemplary embodiments disclosed in the present application will be described in more detail below with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0046] Refer to Figure 1 As shown, an embodiment of the present invention provides a braking protection method for a DC brushless geared motor, including:

[0047] 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;

[0048] Take the maximum braking rate as the initial braking rate of the motor, determine the first correction torque of the motor according to the real-time braking torque and the braking torque threshold, set the real-time braking torque as the first correction torque, and determine whether to adjust the first correction torque according to the real-time motor temperature; if it is not necessary to adjust the first correction torque, take the first correction torque as the final braking torque, if adjustment is required, adjust according to the real-time motor temperature to obtain the second correction torque, and take the second correction torque as the final braking torque;

[0049] Adjust the initial braking rate until the real-time braking torque of the motor remains the same as the final braking torque.

[0050] It should be noted that the electric shock load refers to the equipment or device driven by a DC brushless reduction motor, such as a conveyor belt, a lift, a robot joint, etc. The maximum braking rate refers to the maximum deceleration that can be achieved when the motor load is braking, and the braking rate refers to the deceleration of the motor when braking.

[0051] It can be understood that traditional braking methods usually use a fixed braking torque. However, due to different load sizes, inertias, and working conditions, the fixed torque may cause excessive or insufficient braking. This method obtains the real-time braking torque of the motor and dynamically calculates the first correction torque by combining it with the threshold of the braking torque that the motor can withstand. Then, it further determines whether to adjust it to the second correction torque by combining the real-time motor temperature, ensuring that the braking torque is always within a reasonable range, making the braking process smoother, reducing the impact on the transmission system, and avoiding damage to mechanical components. When the motor brakes, both electromagnetic braking and reverse current braking will generate heat. If not controlled, it may cause the motor temperature to be too high, resulting in insulation aging, winding damage, and even affecting the motor life. This method monitors the motor temperature in real time, establishes a curve of temperature change over time, and calculates the temperature rise rate (the slope of the curve). If the motor temperature exceeds the allowable operating temperature, the braking torque will be reduced to lower the braking energy consumption, thus avoiding overheating damage to the motor; if the temperature rise rate tends to zero, indicating that the temperature is stabilizing, the braking torque will be appropriately increased to improve the braking efficiency. This dynamic temperature regulation mechanism can effectively prevent overheating and improve the reliability of the motor during long-term operation. The rationality of the braking rate is crucial for the safe operation of the motor and its load. If the braking is too fast, it will cause severe impacts on the transmission components, resulting in damage to bearings and gears; if the braking is too slow, it may affect the operation efficiency and even lead to load overflow or accumulation. This method first sets the initial braking rate and continuously adjusts it during the braking process to make the real-time braking torque consistent with the final braking torque. This can ensure the braking effect while avoiding impact loads and improving the safety of the transmission system. Since this method can intelligently adjust the braking torque and braking rate, avoid excessive impact loads during braking, and prevent the performance decline of the motor due to overheating, it can effectively reduce the wear of the motor and the mechanical structure. In the long run, this intelligent braking strategy can reduce the failure rate of the motor and its transmission system, reduce the maintenance cost, 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, and historical operation data and can dynamically adjust the braking parameters, it can maintain a better braking effect under different load conditions, ambient temperatures, and operating states. For example, under high-load working conditions, it will automatically reduce the braking torque to protect the transmission structure, while under light-load working conditions, it can appropriately increase the braking torque to improve the braking efficiency. This intelligent adjustment method makes this method have wide applicability and can meet the needs of various industrial applications.

[0052] In some embodiments of the present application, determining a first correction torque of the motor according to the real-time braking torque and the braking torque threshold includes:

[0053] Collecting historical feature data, where the historical feature data includes the total load mass and the historical motor temperature at corresponding times; determining a safety margin torque according to the historical feature 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:

[0054] ;

[0055] Wherein, 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 load mass, is the historical maximum total load mass.

[0056] 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 too large 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 variations such as conveyor belts or lifting equipment. This method calculates the change in the current total load mass relative to the historical maximum load, enabling dynamic adjustment of braking parameters to ensure the best braking effect under different load conditions and avoid safety issues 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. Since heat is generated during the braking process, the motor temperature may rise to a dangerous range. This method calculates the temperature difference and the maximum allowable temperature to determine whether the motor will overheat due to braking and dynamically adjusts the braking torque to avoid the temperature exceeding the safe range, reducing problems such as insulation aging and efficiency reduction caused by overheating, and thus extending the service life of the motor. Variables such as the maximum braking rate, initial braking rate, and braking time are introduced into the formula, enabling the braking process to be adaptively adjusted according to the current operating state. This can ensure that the motor completes braking in the shortest possible time without generating excessive mechanical shock and improving the overall braking efficiency. Since inertial loads during the braking process may cause mechanical shock, this method calculates the ratio of the motor load to the historical maximum load, enabling the braking torque to vary smoothly under large load conditions, avoiding problems such as equipment damage or material sliding caused by overly fierce braking, and improving the stability and safety of braking.

[0057] In some embodiments of the present application, determining whether to adjust the first correction torque according to the real-time motor temperature includes:

[0058] When setting the real-time braking torque 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 curve slope;

[0059] When the real-time motor temperature is greater than or equal to the maximum allowable operating temperature of the motor, reduce the first correction torque; when the real-time motor temperature is less than the maximum allowable operating temperature of the motor, obtain the real-time curve slope. When the curve slope is less than or equal to zero, increase the first correction torque; when the curve slope is greater than zero, do not adjust the first correction torque.

[0060] It should be noted that by monitoring the motor temperature in real time 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, improving safety and reliability. By using the temperature change curve and slope calculation, the adjustment of the braking torque is made more precise. 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; while when the temperature rises rapidly (curve slope > 0), the braking torque remains unchanged to avoid temperature runaway. While ensuring the braking effect, the braking torque is reasonably controlled to enable the motor to operate within the working temperature range, avoiding problems such as aging of insulating 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 the dynamic feedback of temperature, enabling the braking strategy to be automatically optimized according to the actual working conditions without manual intervention, improving the intelligent level and making it applicable to different loads and environmental conditions.

[0061] In some embodiments of the present application, when reducing the first correction torque, it includes:

[0062] Calculating the temperature difference between the real-time motor temperature and the maximum allowable operating temperature of the motor, and counting the duration during which the real-time motor temperature is greater than or equal to the maximum allowable operating temperature of the motor, denoted as the overload time. Determining the second correction torque according to the temperature difference and the overload time, and the second correction torque satisfies the following relationship:

[0063] ;

[0064] Wherein, is the second correction torque, is the first correction torque, 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].

[0065] 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 the duration is long, the braking torque is gradually reduced to avoid damage to the motor caused by overload. The formula comprehensively considers the temperature difference and the overload time The influence is such that the adjustment of the braking torque depends not only on the current temperature but also takes into account the duration of overloading. This allows for maintaining a relatively high braking torque in the case of short-term overheating, while reducing the braking torque in the case of long-term overheating to ensure stable operation. Using the first attenuation coefficient causes the braking torque to gradually decrease as the overloading time increases, rather than making a sudden adjustment, thereby reducing the impact and avoiding affecting the normal operation of the motor due to too rapid an adjustment of the braking torque. In the formula sets an overloading time threshold under safe operating conditions, while is adjustable as the attenuation coefficient, capable of adapting to different types of load conditions and improving the adaptability and intelligence level of the braking protection strategy.

[0066] In some embodiments of the present application, when increasing the first correction torque, it includes:

[0067] Determining the second correction torque based on the absolute value of the temperature difference and the curve slope. The second correction torque is determined through the following relationship:

[0068] ;

[0069] Wherein, is the second correction torque, is the first correction torque, is the temperature difference, is the second attenuation coefficient, and the value range of β is (0.5, 1], is the curve slope.

[0070] It should be noted that by introducing the temperature difference and the exponential correction model, the braking torque is adjusted in real time. When the motor temperature is lower than the maximum allowable temperature and the temperature reduction trend is obvious, the braking torque can be appropriately increased to improve the braking effect, while ensuring that the motor will not experience unstable braking due to insufficient braking torque. Using the second attenuation coefficient ensures that the change in the braking torque does not increase suddenly, but is adjusted smoothly as the temperature difference changes, avoiding a sudden increase in torque during braking and affecting stability. This formula calculates the difference between the maximum allowable temperature and the current temperature, reasonably utilizes the temperature margin of the motor, and maximizes the braking torque as much as possible under the premise of ensuring safety, thereby improving the braking efficiency. By adjusting the attenuation coefficient, different load conditions can be adapted, making the adjustment of the braking torque more flexible, so as to be applicable to different types of loads and operating environments and improve the intelligence level.

[0071] In addition, the first attenuation coefficient is determined by the following method: Set multiple levels of preset overload times. A number of preset overload times are sorted in ascending order according to their values. Each two adjacent preset overload times form an interval, and a value of the first attenuation coefficient is assigned to each interval, with the value range being (0.5, 1]. According to the magnitude of the overload time, it is incorporated into the corresponding interval, thereby obtaining the value of the first attenuation coefficient corresponding to this interval. Similarly, by setting multiple preset temperature differences, another value of the first attenuation coefficient is obtained. Finally, the average value of the two values is used as the final first attenuation coefficient.

[0072] The method for determining the second attenuation coefficient is the same as that for the first attenuation coefficient. The difference is that the second attenuation coefficient is obtained by setting the absolute value of multiple temperature differences and the preset value of the curve slope, then delimiting intervals to obtain two values of the second attenuation coefficient, and calculating their average value as the final second attenuation coefficient.

[0073] 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:

[0074] Obtain historical braking data, which includes the curve of historical braking torque and the adjustment amount of torque unit changing with time. Compare the real-time braking torque with the historical braking data. When there is a historical braking torque equal to the real-time braking torque, intercept the curve until the historical braking torque is the same as the final braking torque, and then stop intercepting and obtain the start and end times at both ends of the intercepted curve; Obtain the historical motor temperature in the corresponding historical feature data and the difference between the start and end times according to the start and end times. Compare the historical motor temperature with the maximum allowable working temperature of the motor and the difference between the start and end times with the preset time threshold respectively. 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 times is less than or equal to the time threshold, obtain the curve of the adjustment amount of torque unit changing with time, and adjust the real-time braking torque to be the same as the final braking torque according to the adjustment amount of torque unit;

[0075] When the difference between the start and end times is greater than the time threshold, it is determined that there is no case where the historical braking torque or the real-time braking torque is equal.

[0076] It should be noted that historical braking data with the same total mass of the current motor load is selected. The adjustment amount of torque unit is the adjustment amount of torque per unit time.

[0077] 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 using it to make the adjustment more precise, avoid excessive or insufficient adjustment, and improve braking stability. Extracting the appropriate braking torque adjustment curve directly from the historical data instead of relying entirely on real-time calculation reduces the computational complexity and improves the response speed, making 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, thereby preventing the motor from overheating and improving the safety and reliability of the braking process. Through the curve of the change of the torque unit adjustment amount over time, the real-time braking torque is gradually adjusted to be consistent with the final braking torque, ensuring a smooth braking process, avoiding abrupt changes, and improving braking accuracy and comfort. Select the historical braking data with the same total mass of the current motor load to ensure that the adjustment strategy is optimized for the specific load situation, enabling the method to adapt to different load conditions and improving generality and adaptability.

[0078] In some embodiments of the present application, the real-time braking torque is compared with the historical braking data. When there is no historical braking torque or the real-time braking torque is equal, the differences between the real-time braking torque and the final braking torque and the historical braking data are calculated, denoted as the first difference and the second difference.

[0079] 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. According to the two historical braking data, intercept the curve and obtain the historical motor temperature based on 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 both 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.

[0080] When the time difference is greater than the preset time threshold, sort all the sums of the first difference and the second difference from small to large, select them in turn and judge the size relationship between the time difference and the preset time threshold until the time difference is less than or equal to the time threshold.

[0081] 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, avoiding inappropriate braking caused by overly sudden or uncertain current situations. Calculate the differences between the real-time braking torque and the final braking torque (the first difference and the second difference), and select the historical data with the smallest difference for reference to ensure that the adjusted braking torque is close to the optimal braking value in historical experience. When selecting historical braking data, judge whether to adjust the braking torque based on the time difference and the motor temperature. By setting a time threshold, ensure that the time difference between the selected historical data and the current operation is within a reasonable range, avoiding the influence of data with too long time differences on the braking effect. In addition, check the historical motor temperature to ensure that the historical motor temperature does not exceed the maximum allowable working temperature of the motor, avoiding damage to the motor due to overheating. If these conditions are met, the braking torque will be adjusted so that the braking process is smoother and safer when the motor is under a large load. 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 can ensure a smoother braking transition and avoid adverse effects on the motor and transmission system caused by sudden drastic changes. By comparing the differences and minimizing the discrepancies, sudden large-scale adjustments of the braking torque can be avoided, thereby reducing the impact on the motor and transmission system and maintaining stability and long life. By adaptively selecting historical data to adjust the current braking torque, this makes the braking control not only rely on the current state but also predict and optimize the braking effect based on historical performance. This method improves the intelligence and adaptability of braking control and can cope with changes under different working conditions. This method not only relies on historical data but also monitors and adjusts the braking torque in real time to ensure the optimal braking effect under the current operating conditions. This dynamic adjustment method makes the braking more flexible and can adapt to different load and temperature conditions. By comprehensively considering historical braking data and current real-time data, the situation of over-braking can be avoided. Especially when the load changes or the motor temperature rises, the braking torque can be adjusted more flexibly to avoid damage to the motor caused by over-braking. By selecting historical data according to the minimization of the difference, the braking torque can be accurately adjusted to avoid excessive deviation and ensure a more precise and stable braking process.

[0082] In some embodiments of the present application, when the historical motor temperature is greater than the maximum allowable working temperature of the motor, calculate the difference between the historical motor temperature and the maximum allowable working temperature of the motor, denoted as the historical temperature difference, and down-regulate the torque unit adjustment amount according to the magnitude of the historical temperature difference, and the down-regulation amount has a linear proportional relationship with the historical temperature difference.

[0083] It should be noted that during the operation of the motor, excessive heat may be generated 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, calculate the historical temperature difference (i.e., the difference between the historical motor temperature and the maximum allowable operating temperature of the motor). This temperature difference reflects the current overheating degree of the motor. Through the temperature difference, it can be evaluated whether the motor is in an overloaded or overheated state. The downward adjustment torque unit adjustment amount has a linear proportional relationship with the historical temperature difference. That is to say, the greater the difference between the historical motor temperature and the maximum operating temperature, the greater the adjustment amount of the torque unit, and thus the braking torque is reduced. In this way, the system can actively reduce the braking force when the motor temperature is too high, avoiding the continuous generation of heat. This downward adjustment mechanism can help protect the motor from overheating damage and avoid the decline of motor performance, insulation damage or other failures caused by too high temperature. When the motor temperature is too high, if too large a braking torque is continuously applied, it will cause the motor temperature to rise further, increasing the risk of motor damage. By reducing the braking torque, the system can actively reduce the burden when the motor is overheated, thus avoiding permanent damage to the motor caused by overheating.

[0084] Refer to Figure 2 As shown, an embodiment of the present invention provides a braking protection system for a DC brushless reduction motor, including:

[0085] An acquisition module configured to obtain the maximum braking rate when the motor load brakes, the braking torque threshold that the motor can withstand, the real-time braking torque, and the real-time motor temperature;

[0086] A first correction module configured to use the maximum braking rate as the initial braking rate of the motor, determine the 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;

[0087] A 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, 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;

[0088] Adjust the initial braking rate until the real-time braking torque of the motor remains the same as the final braking torque.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific implementation manners of the present invention, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered by the protection scope 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; Adjusting the initial braking rate until the real-time braking torque of the motor remains the same as the final braking torque; Determining a first correction torque of the motor according to the real-time braking torque and the braking torque threshold includes: Collecting historical characteristic data, the historical characteristic data including: the total mass of the load and the historical motor temperature at the corresponding time; determining 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; 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.

2. The brake protection method for a brushless DC motor according to claim 1, 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.

3. The brake protection method for a brushless DC motor according to claim 2, 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].

4. The brake protection method for a brushless DC reduction motor according to claim 3, 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.

5. The brake protection method for a brushless DC motor according to claim 4, 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.

6. The brake protection method for a brushless DC reduction motor according to claim 5, 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.

7. The brake protection method for a brushless DC reduction motor according to claim 6, 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.

8. 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 7, 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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