Motor control method

Abstract

The invention provides a motor control method, which comprises the following steps: acquiring operation parameters of a motor, the operation parameters comprising current I, resistance R and rotating speed n; acquiring the temperature rise rate of the motor according to the operation parameters; obtaining a motor temperature change curve T (t) according to the temperature rise rate; and comparing the current operating temperature of the motor with the motor temperature change curve T (t) so as to control the motor to send out an early warning signal or control the motor to operate normally. The problem that motor aging is accelerated due to lagging of motor heat detection in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor heat detection, and in particular to a motor control method. Background Art

[0002] Motors are the most basic power source in modern society and are widely used in various industries. Motors generate heat during operation. If the heat accumulates too much and is not detected and treated in time, it will seriously affect the performance and life of the motor. Therefore, timely and accurate monitoring and early warning of motor overheating are crucial to ensure safe and efficient operation of the motor.

[0003] In the prior art, the motor temperature detection method often responds only after the temperature has obviously increased, which has a large hysteresis and may cause the motor to continue to run at a high temperature for a period of time, accelerating the aging and damage of the motor. Summary of the invention

[0004] The main purpose of the present invention is to provide a motor control method to solve the problem in the prior art that delayed motor heat detection leads to accelerated motor aging.

[0005] In order to achieve the above object, according to one aspect of the present invention, a motor control method is provided, comprising:

[0006] Obtain the operating parameters of the motor, which include: current I, resistance R, and speed n;

[0007] According to the operating parameters, the temperature rise rate of the motor is obtained;

[0008] According to the temperature rise rate, the motor temperature change curve T(t) is obtained;

[0009] The current operating temperature of the motor is compared with the motor temperature change curve T(t) to control the motor to issue a warning signal or control the motor to operate normally.

[0010] Further, according to the operating parameters, obtaining the temperature rise rate of the motor includes:

[0011] Obtain the power P generated by the heat of the motor, and obtain the heat dissipation power Q of the motor;

[0012] Temperature rise rate dT / dt=(PQ) / (m*c);

[0013] Where m is the mass of the motor and c is the specific heat capacity of the motor material.

[0014] Furthermore, the method for obtaining the power P generated by the heat of the motor includes:

[0015] Obtain resistance loss P1 and obtain hysteresis loss P2;

[0016] Where P1 = I 2 *R, P=P1+P2.

[0017] Furthermore, the method for obtaining the hysteresis loss P2 includes:

[0018] in,

[0019] P2 is the hysteresis loss power (unit: W / kg);

[0020] K h is a constant;

[0021] f is the magnetic field frequency (unit: Hz);

[0022] B m is the maximum magnetic induction intensity.

[0023] Furthermore, the motor temperature variation curve T(t) is:

[0024] T(t)=T+(∫dT / dt)*dt; wherein T and t are time respectively, and t>T.

[0025] Furthermore, the method for obtaining the magnetic field frequency includes: obtaining the pole pair number p of the motor, and obtaining the magnetic field frequency of the motor according to the pole pair number p and the rotation speed n of the motor:

[0026] Furthermore, the method also includes: adjusting the operating state of the motor according to the motor temperature change curve T(t) to maintain the motor within a safe operating temperature range.

[0027] Furthermore, adjusting the operating state of the motor according to the motor temperature variation curve T(t) to maintain the motor within a safe operating temperature range includes: controlling the motor to reduce the speed or controlling the motor to reduce the load.

[0028] Furthermore, the motor control method also includes: when the motor sends out a warning signal, performing a heat dissipation operation on the motor and maintaining it for a predetermined time; then detecting the current temperature of the motor, and judging whether the motor can operate normally according to the motor temperature change curve T(t).

[0029] Furthermore, the motor control method also includes: constructing a safety temperature threshold T1; obtaining the actual temperature T2 of the motor, and when T1-T2=0°C~10°C, issuing a warning signal.

[0030] By applying the technical solution of the present invention, the motor control method provided in the present application obtains a motor temperature change curve according to various operating parameters of the motor, and then compares the current operating temperature of the motor with the motor temperature change curve after obtaining it. According to the comparison result, the operating state of the motor is controlled, which is beneficial to solving the problem of delayed motor temperature detection, and taking defensive measures before the motor temperature has increased significantly, thereby effectively protecting the motor and extending the service life of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0032] Figure 1 A first flow chart showing a motor control method according to the present invention; and

[0033] Figure 2 A second flow chart of the motor control method according to the present invention is shown.

[0034] The above drawings include the following reference numerals: DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application 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.

[0036] As mentioned in the background technology, the motor will generate heat during operation. If the heat accumulates too much and is not discovered and processed in time, it will seriously affect the performance and life of the motor. Existing motor temperature detection methods often respond only after the temperature has risen significantly, and have a large hysteresis, which may cause the motor to continue to run for a period of time under high temperature conditions, accelerating the aging and damage of the motor. Therefore, in response to the above technical problems, the motor control method provided in the present application obtains the motor temperature change curve according to the various operating parameters of the motor, and then compares the current operating temperature of the motor with the motor temperature change curve after obtaining it. According to the comparison result, the operating state of the motor is controlled, which is conducive to solving the problem of motor temperature detection lag, taking defensive measures before the motor temperature has not risen significantly, effectively protecting the motor, and extending the service life of the motor.

[0037] Please refer to Figure 1 and Figure 2The present application provides a motor control method, including: obtaining the operating parameters of the motor, the operating parameters including: current I, voltage U, resistance R, speed n; obtaining the temperature rise rate of the motor according to the operating parameters; obtaining the motor temperature change curve T(t) according to the temperature rise rate; comparing the current operating temperature of the motor with the motor temperature change curve T(t) to control the motor to send a warning signal or control the motor to operate normally.

[0038] The motor control method provided by the present application includes the following steps:

[0039] S100: Acquire the operating parameters of the motor, which include: current I, resistance R, and speed n;

[0040] S200: Obtaining a temperature rise rate of the motor according to the operating parameters;

[0041] S300: Obtaining a motor temperature change curve T(t) according to the temperature rise rate;

[0042] S400: Compare the current operating temperature of the motor with the motor temperature change curve T(t) to control the motor to issue a warning signal or control the motor to operate normally.

[0043] By acquiring the motor's operating parameters in real time, including current (I), resistance (R) and speed (n), and calculating the motor's temperature rise rate based on these parameters, this method can accurately predict the motor temperature change trend and identify the motor overheating risk in advance. Once it is predicted that the temperature may exceed the safe range, the system immediately issues a warning signal, allowing the operator or control system to take measures in advance, such as reducing the load, slowing down the speed, and strengthening heat dissipation, effectively avoiding motor damage caused by overheating and extending the motor's service life. By comparing the motor's current operating temperature with the predicted temperature change curve T(t), the motor's operating state can be intelligently adjusted according to the motor's actual operating conditions and temperature prediction. For example, when the load is light or the ambient temperature is suitable, the motor can be allowed to operate in a more efficient state, and when the risk of overheating is detected, power reduction measures are automatically taken to achieve a balance between motor operating efficiency and safety. By continuously monitoring and predicting motor temperature changes, this method can promptly detect overheating conditions that may cause motor failures, thereby intervening before failures occur, significantly reducing unplanned downtime caused by overheating, and improving the overall reliability of the production system. This control method is based on the basic operating parameters of the motor and has strong versatility. It can be applied to motors of various types and specifications, whether they are AC motors, DC motors, servo motors or stepper motors. It can effectively implement temperature control and early warning, providing a flexible and efficient technical solution for the intelligent management of motors.

[0044] According to the operating parameters, obtaining the temperature rise rate of the motor includes: obtaining the power P generated by the heat of the motor, obtaining the heat dissipation power Q of the motor; temperature rise rate dT / dt=(PQ) / (m*c); where m is the mass of the motor, and c is the specific heat capacity of the motor material.

[0045] By collecting the motor's operating parameters in real time, such as current, voltage, resistance, speed, and load, the motor's heat generation power P and heat dissipation power Q can be accurately calculated. The temperature rise rate calculated using these data can more accurately predict the temperature change trend of the motor, thereby realizing real-time monitoring and intelligent control of the motor temperature to avoid damage to the motor due to overheating. This method can respond quickly and take corresponding control measures based on the current thermal status of the motor and the predicted temperature change. For example, when it is detected that P (heat generation power) is much greater than Q (heat dissipation power), that is, the dT / dt value is large, indicating that the motor temperature rises too fast, the system can immediately adjust the motor's operating status, such as reducing the speed, reducing the load, or enhancing heat dissipation, to reduce dT / dt and keep the motor running within a safe temperature range. Motor overheating is one of the main reasons for its performance degradation and shortened life. This method effectively prevents the motor from running for a long time in a high temperature environment by predicting and controlling the temperature rise in advance, thereby reducing the impact of thermal stress on motor components and extending the service life of the motor. The formula dT / dt=(PQ) / (m*c) for calculating the temperature rise rate in this method is universal and can be applied to different types of motors by simply adjusting the values ​​of m (motor mass) and c (specific heat capacity of motor material).

[0046] The method for obtaining the power P generated by the heat of the motor includes: obtaining the resistance loss P1, obtaining the hysteresis loss P2; P = P1 + P2. P1 = I 2 *R.

[0047] By decomposing the heat generating power P of the motor into the resistance loss P1 (P1 = I 2*R) and hysteresis loss P2, the total heat generation of the motor during operation can be calculated more accurately. This calculation method takes into account the direct impact of the current and resistance on the heat generation during motor operation, as well as the contribution of factors such as speed and flux density to hysteresis loss, so that the heat generation power closer to the actual situation can be obtained. The real-time calculation of resistance loss and hysteresis loss enables the system to monitor the changing trend of motor heat in a timely manner. When the calculated total heat generation power P exceeds the normal heat dissipation capacity of the motor, or indicates that the motor temperature is about to exceed the safety threshold, the system can issue an early warning signal in advance. This helps to take preventive measures before overheating occurs, such as adjusting the load, reducing the speed or strengthening the heat dissipation, to avoid damage to the motor due to overheating, and enhance the safety and reliability of the motor operation. By refining the calculation of heat generation power, the heat generation of the motor under different operating parameters can be analyzed more accurately. This provides data support for adjusting the motor operation status, so that while ensuring the safety of the motor, its operating efficiency can be optimized, such as reducing unnecessary power consumption under low load or low speed conditions, to achieve the goal of energy saving and consumption reduction. Accurate heat calculation and early warning mechanisms help prevent the motor from running in an overheated state for a long time, reducing the risk of accelerated aging and damage of the motor due to overheating, thereby extending the service life of the motor in long-term operation and reducing maintenance and replacement costs.

[0048] Methods for obtaining the hysteresis loss P2 include:

[0049] in,

[0050] P2 is the hysteresis loss power (unit: W / kg);

[0051] K h It is a constant; it is related to the material (typical value: silicon steel sheet 0.01~0.02; amorphous alloy: 0.001~0.002)

[0052] f is the magnetic field frequency (unit: Hz);

[0053] B m is the maximum magnetic induction intensity.

[0054] The method for obtaining the magnetic field frequency includes: obtaining the pole pair number p of the motor, and obtaining the magnetic field frequency of the motor according to the pole pair number p and the motor speed n:

[0055] In practical applications, temperature also affects hysteresis loss. The temperature coefficient α can be introduced T To correct for the effect of temperature:

[0056]

[0057] in:

[0058] α T is the temperature coefficient, usually determined from experimental data

[0059] Consider the influence of stress:

[0060] Stress also affects hysteresis loss, and the stress coefficient α can be introduced σ To correct for the effects of stress:

[0061]

[0062] The load F of the motor directly affects its heat generation, which is mainly reflected by copper loss (resistance loss) and iron loss (hysteresis loss). The load of the motor is usually expressed by its output power P.

[0063] Specifically, the motor temperature variation curve T(t) is: T(t)=T+(∫dT / dt)*dt, wherein T and t are time respectively, and t>T. For example, T is 1s, and t is 2s.

[0064] By continuously collecting the operating parameters of the motor, and using these parameters to calculate the real-time temperature rise rate dT / dt, and then integrating to obtain the temperature change curve T(t), this method can provide an accurate prediction of the change of motor temperature over time. This allows the trend of temperature increase to be foreseen before the motor actually overheats, so that measures can be taken in advance to avoid motor damage. Based on the T(t) curve, when the predicted temperature exceeds the safety threshold, the system can automatically issue a warning signal to remind the operator or control system to take measures such as reducing the load, adjusting the speed or strengthening the heat dissipation to prevent the motor from overheating. This not only improves the safety of motor operation, but also reduces unplanned downtime and maintenance costs caused by overheating. The dynamic characteristics of the T(t) curve allow the system to adjust its operating state in real time according to the changing trend of the motor temperature. For example, if the temperature is predicted to rise, the system can reduce the power output of the motor or increase the cooling efficiency; if the temperature is predicted to be stable or decrease, the system can restore the motor to a more efficient working state to achieve optimal utilization of resources.

[0065] The calculation of the hysteresis loss P2 is based on the operating speed n and magnetic flux density B of the motor, and is obtained through empirical formulas or experimental data fitting.

[0066] Hysteresis loss is the energy loss of the core material caused by the frequent changes in the magnetic field during the operation of the motor. Its size is closely related to the speed and flux density of the motor. By establishing a hysteresis loss calculation model based on the speed n and the flux density B, the hysteresis loss P2 of the motor under different operating conditions can be more accurately evaluated, thereby improving the accuracy of the prediction of the total loss of the motor. In the design stage of the motor, the core material, magnetic circuit design and operating parameters of the motor can be optimized using an accurate hysteresis loss calculation method. For example, selecting a core material with lower hysteresis loss, or adjusting the speed and flux density of the motor to reduce hysteresis loss, can help design more efficient and energy-saving motor products. During the operation of the motor, real-time calculation of the hysteresis loss P2 helps the intelligent control system to more accurately evaluate the total power loss of the motor, thereby dynamically adjusting the operating state of the motor, such as speed, load, etc., according to actual needs, to reduce unnecessary energy consumption and achieve energy-saving operation. The heat generated by hysteresis loss is one of the important factors that cause the temperature of the motor to rise. By accurately calculating the hysteresis loss and taking measures to control it, the temperature of the motor can be effectively reduced, the damage to the motor components caused by thermal stress can be reduced, and the service life of the motor can be extended.

[0067] The method also includes: adjusting the operating state of the motor according to the motor temperature change curve T(t) to maintain the motor within a safe operating temperature range.

[0068] The active control strategy based on the temperature change curve T(t) can monitor the temperature trend of the motor in real time. When it is predicted that the temperature may rise to an unsafe level, the system will automatically take measures such as reducing the load, adjusting the speed or enhancing heat dissipation to avoid overheating of the motor. Compared with traditional passive cooling or temperature monitoring, this method can more effectively manage the motor temperature and prevent overheating damage. By dynamically adjusting the operating state of the motor, it can ensure that the motor operates within a safe temperature range and avoid frequent shutdowns due to overheating protection, thereby improving the operating efficiency of the motor and the overall efficiency of the production system. On the premise of ensuring safety, the system can also optimize the load and speed of the motor according to the actual temperature and the predicted curve to achieve more efficient and energy-saving operation. Overheating of the motor is one of the main reasons for its shortened life. This method adjusts the operating state in real time to maintain the motor working within an appropriate temperature range, reducing the damage of thermal stress to the internal components of the motor, thereby extending the service life of the motor and reducing maintenance and replacement costs.

[0069] The motor temperature variation curve T(t) adjusts the running state of the motor to maintain the motor within a safe operating temperature range, including: controlling the motor to reduce the speed or controlling the motor to reduce the load.

[0070] When the system predicts that the temperature of the motor will exceed the preset safe operating temperature range, the motor's heat generation rate can be immediately reduced by actively reducing the motor's speed or load, effectively preventing the motor from overheating and avoiding motor damage caused by high temperature. Long-term operation of the motor at high temperature will accelerate its aging and affect its service life. This method prevents the motor from being in an overheated state for a long time through early intervention, thereby significantly extending the motor's service life and reducing maintenance and replacement costs. Motor overheating not only affects its performance, but may also cause safety accidents such as fire. Controlling the motor temperature by adjusting the operating state can effectively improve the safety of motor operation and reduce potential safety risks. Under the premise of ensuring the safe operation of the motor, by finely managing the motor's speed and load, unnecessary power loss is avoided, the motor's energy utilization efficiency is improved, and it is helpful to save energy and reduce emissions and reduce energy costs. Motor overheating is one of the main reasons for its frequent maintenance. This method reduces the occurrence of overheating by controlling the motor temperature in advance, thereby reducing the maintenance frequency and complexity of the motor and improving production efficiency. The use of the motor temperature change curve T(t) to guide the adjustment of the operating state embodies the concept of intelligent management. This control method based on data prediction can realize automatic and intelligent motor management, reduce the need for manual intervention, and improve the management level. For motors operating under complex working conditions, such as high load and long operation in industrial production, or working in an environment with large temperature fluctuations, this method can respond flexibly and ensure stable operation of the motor within a safe temperature range by dynamically adjusting the speed or load, thereby improving the adaptability and reliability of the motor under various working conditions.

[0071] The motor control method also includes: when the motor sends out a warning signal, performing a heat dissipation operation on the motor and maintaining it for a predetermined time; then detecting the current temperature of the motor and judging whether the motor can operate normally according to the motor temperature change curve T(t).

[0072] When the warning signal is triggered, the heat dissipation mechanism is immediately started, such as increasing the fan speed, starting the cooling water circulation or enabling the backup heat dissipation system, which can directly reduce the temperature of the motor and avoid the motor performance degradation or damage caused by overheating. Maintaining the heat dissipation operation for a predetermined time ensures that the motor has enough time to cool down to a safe temperature range. The temperature change curve T(t) is used to evaluate the state of the motor after cooling to determine whether it can be restored to the normal operating temperature, thereby determining whether it can continue to operate. This data-based intelligent decision can ensure that the motor is restarted under safe temperature conditions and avoid the risk of overheating again caused by blindly resuming operation. By accurately controlling the temperature of the motor, unplanned downtime and motor failure caused by overheating are avoided, and the stability of the motor operation is improved. At the same time, regular monitoring and active heat dissipation mechanisms can enhance the reliability of the long-term operation of the motor and reduce the maintenance requirements caused by temperature-related problems. Overheating is one of the main causes of motor aging and shortened life. This method effectively reduces the running time of the motor in a high temperature environment by timely heat dissipation and intelligently judging whether the motor can operate normally, thereby reducing the impact of thermal stress on motor components and extending the service life of the motor. When the motor overheating warning is issued, timely heat dissipation measures and temperature status assessment can avoid unnecessary motor shutdown and reduce production interruptions. It also reduces the energy consumption increased by overheating, achieving a dual improvement in production efficiency and energy efficiency.

[0073] The motor control method also includes: establishing a safety temperature threshold T1; obtaining the actual temperature T2 of the motor, and when T1-T2=0°C~10°C, issuing a warning signal.

[0074] By setting a safe temperature threshold T1, this method can issue an early warning signal when the motor temperature approaches but has not yet reached the critical value that may cause damage. This allows the operator or control system to have enough time to take preventive measures to avoid overheating of the motor, thereby reducing motor damage caused by overheating, achieving preventive maintenance, and extending the service life of the motor. When the motor runs under conditions higher than the safe temperature threshold, it will not only accelerate the wear of the motor, but may also cause safety accidents such as fire. By real-time monitoring of the actual temperature T2 of the motor and comparing it with the safety threshold T1, this method ensures that the motor always runs within a safe temperature range, significantly improving the safety of motor operation. When it is detected that the temperature difference between T2 and T1 enters the warning range, the system automatically issues a warning signal and may automatically take corresponding measures, such as adjusting the load, reducing the speed, or strengthening heat dissipation, reducing the need for manual intervention and improving production efficiency and automation. The issuance of the warning signal is not only a warning of the risk of overheating, but also a basis for adjusting the operating state of the motor. For example, when the motor temperature approaches the safety threshold, the system can automatically adjust the working parameters, such as speed, load, etc., to reduce the heat generation of the motor and keep it in the best operating state. The setting of the safety temperature threshold T1 can be flexibly adjusted according to the specific model, application environment and operation requirements of the motor. This makes this method suitable for both large motors in industrial production and small motors in household appliances, and has wide applicability and practicality. Reducing equipment shutdown and motor damage caused by overheating can effectively avoid production interruptions and improve the overall efficiency of the production line. At the same time, the maintenance and replacement frequency of the motor is reduced through preventive maintenance, which reduces the cost of long-term operation and improves economic benefits. This method can be applied to different ambient temperatures and working conditions. As long as the safety temperature threshold T1 is adjusted according to the actual situation, it can ensure the stable and safe operation of the motor under various environmental conditions, and enhance the environmental adaptability of the motor control system.

[0075] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0076] The motor control method provided in the present application obtains a motor temperature change curve based on various operating parameters of the motor, and then compares the current operating temperature of the motor with the motor temperature change curve after obtaining it. According to the comparison result, the operating state of the motor is controlled, which is beneficial to solving the problem of delayed motor temperature detection. Defense measures can be taken before the motor temperature rises significantly, thereby effectively protecting the motor and extending the service life of the motor.

[0077] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0078] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0079] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0080] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0081] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A motor control method, characterized in that: include: Acquire the operating parameters of the motor, wherein the operating parameters include: current I, resistance R, and speed n; According to the operating parameters, obtaining the temperature rise rate of the motor; According to the temperature rising rate, the motor temperature variation curve T(t) is obtained; The current operating temperature of the motor is compared with the motor temperature variation curve T(t) to control the motor to issue a warning signal or control the motor to operate normally.

2. The motor control method according to claim 1, characterized in that: According to the operating parameters, obtaining the temperature rise rate of the motor includes: Obtain the power P generated by the heat of the motor, and obtain the heat dissipation power Q of the motor; The temperature rise rate dT / dt=(PQ) / (m*c); Where m is the mass of the motor and c is the specific heat capacity of the motor material.

3. The motor control method according to claim 2, characterized in that: The method for obtaining the power P generated by the heat of the motor includes: Obtain resistance loss P1 and obtain hysteresis loss P2; Where P1 = I 2 *R, P=P1+P2.

4. The motor control method according to claim 3, characterized in that: Methods for obtaining the hysteresis loss P2 include: in, P2 is the hysteresis loss power (unit: W / kg); K h is a constant; f is the magnetic field frequency (unit: Hz); B m is the maximum magnetic induction intensity.

5. The motor control method according to claim 1, characterized in that: The motor temperature variation curve T(t) is: T(t) = T + (∫dT / dt)*dt; Wherein, T and t are time respectively, and t>T.

6. The motor control method according to claim 4, characterized in that: Methods for obtaining the magnetic field frequency include: The number of pole pairs p of the motor is obtained, and according to the number of pole pairs p and the speed n of the motor, the magnetic field frequency of the motor is obtained as follows:

7. The motor control method according to claim 1, characterized in that: The method further comprises: The operating state of the motor is adjusted according to the motor temperature variation curve T(t) to maintain the motor within a safe operating temperature range.

8. The motor control method according to claim 7, characterized in that: Adjusting the operating state of the motor according to the motor temperature change curve T(t) to maintain the motor within a safe operating temperature range includes: The motor is controlled to reduce the rotation speed or the motor is controlled to reduce the load.

9. The motor control method according to claim 8, characterized in that: The motor control method further comprises: When the motor sends out a warning signal, a heat dissipation operation is performed on the motor and maintained for a predetermined time; Then, the current temperature of the motor is detected, and according to the motor temperature variation curve T(t), it is determined whether the motor can operate normally.

10. The motor control method according to claim 1, characterized in that: The motor control method further comprises: Construct a safe temperature threshold T1; The actual temperature T2 of the motor is obtained, and when T1-T2=0°C-10°C, an early warning signal is issued.

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