Rotor permanent magnet temperature detection method, device, electronic device and storage medium

Abstract

The present application discloses a method, device, electronic device and storage medium for detecting the temperature of a rotor permanent magnet. The method for detecting the temperature of the rotor permanent magnet includes: when the magnetic levitation motor is running, measuring a first thermal expansion amount corresponding to the stator of the magnetic levitation motor and measuring a second thermal expansion amount corresponding to the body of the magnetic levitation motor; determining a rotor thermal elongation amount corresponding to the rotor of the magnetic levitation motor according to the first thermal expansion amount and the second thermal expansion amount; and detecting the real-time temperature of the rotor permanent magnet on the rotor according to the rotor thermal elongation amount. The present application solves the technical problem of low accuracy in detecting the temperature of the rotor permanent magnet in the prior art.

Description

Technical Field

[0001] This application relates to the technical field of motors, and particularly to a method, device, electronic device, and storage medium for detecting the temperature of a rotor permanent magnet. Background Technique

[0002] When a magnetic levitation high-speed motor operates, it usually generates heat, causing the temperature of the rotor permanent magnet to rise. Therefore, it is often necessary to detect the temperature of the rotor permanent magnet. Currently, the temperature of the rotor permanent magnet can be measured by the parameter estimation method. Specifically, by estimating parameters related to temperature such as the stator winding resistance and permanent magnet flux linkage of a permanent magnet synchronous motor, and then using the approximate linear relationship between these parameters and temperature to monitor the temperature of the rotor permanent magnet of the high-speed motor. However, this method is based on the assumption that the stator and rotor temperatures are equal, which does not conform to the actual scenario and affects the accuracy of the rotor permanent magnet temperature detection. Summary of the Invention

[0003] The main purpose of this application is to provide a method, device, electronic device, and storage medium for detecting the temperature of a rotor permanent magnet, aiming to solve the technical problem of low accuracy in detecting the temperature of the rotor permanent magnet in the prior art.

[0004] To achieve the above object, this application provides a method for detecting the temperature of a rotor permanent magnet. The method for detecting the temperature of the rotor permanent magnet includes:

[0005] When the magnetic levitation motor is operating, measuring a first thermal expansion amount corresponding to the stator of the magnetic levitation motor, and measuring a second thermal expansion amount corresponding to the body of the magnetic levitation motor;

[0006] Determining a rotor thermal elongation amount corresponding to the rotor of the magnetic levitation motor according to the first thermal expansion amount and the second thermal expansion amount;

[0007] Detecting the real-time temperature of the rotor permanent magnet on the rotor according to the rotor thermal elongation amount.

[0008] To achieve the above object, this application also provides a device for detecting the temperature of a rotor permanent magnet. The device for detecting the temperature of the rotor permanent magnet includes:

[0009] A measurement module, configured to measure a first thermal expansion amount corresponding to the stator of the magnetic levitation motor and measure a second thermal expansion amount corresponding to the body of the magnetic levitation motor when the magnetic levitation motor is operating;

[0010] A determination module, configured to determine a rotor thermal elongation amount corresponding to the rotor of the magnetic levitation motor according to the first thermal expansion amount and the second thermal expansion amount;

[0011] A temperature detection module is configured to detect the real-time temperature of the rotor permanent magnet on the rotor according to the thermal elongation of the rotor.

[0012] The present application also provides an electronic device, which is a physical device. The electronic device includes: a memory, a processor, and a program of the rotor permanent magnet temperature detection method stored on the memory and executable on the processor. When the program of the rotor permanent magnet temperature detection method is executed by the processor, the steps of the rotor permanent magnet temperature detection method as described above can be realized.

[0013] The present application also provides a computer-readable storage medium, on which a program for implementing the rotor permanent magnet temperature detection method is stored. When the program of the rotor permanent magnet temperature detection method is executed by the processor, the steps of the rotor permanent magnet temperature detection method as described above are realized.

[0014] The present application also provides a computer program product, including a computer program. When the computer program is executed by the processor, the steps of the rotor permanent magnet temperature detection method as described above are realized.

[0015] The present application provides a rotor permanent magnet temperature detection method, device, electronic device and storage medium. That is, when the magnetic levitation motor is running, measure the first thermal expansion amount corresponding to the stator of the magnetic levitation motor and the second thermal expansion amount corresponding to the body of the magnetic levitation motor; according to the first thermal expansion amount and the second thermal expansion amount, determine the rotor thermal elongation amount corresponding to the rotor of the magnetic levitation motor, achieving the purpose of indirectly measuring the rotor thermal elongation amount by measuring the thermal expansion amount of the stator and the overall thermal expansion amount of the body. Thus, according to the principle of thermal expansion of objects, the real-time temperature of the rotor permanent magnet on the rotor can be accurately detected according to the rotor thermal elongation amount. Without assuming that the temperatures of the stator and the rotor are equal, but directly detecting the real-time temperature of the rotor permanent magnet based on the thermal elongation amount associated with the rotor, which conforms to the actual scene during the operation of the magnetic levitation motor. Therefore, it overcomes the technical defect in the prior art that it is necessary to estimate temperature-related parameters such as the stator winding resistance and the permanent magnet flux linkage of the permanent magnet synchronous motor based on the assumption that the temperatures of the stator and the rotor are equal, and then use the approximate linear relationship between these parameters and temperature to monitor the temperature of the motor rotor permanent magnet, improving the accuracy of rotor permanent magnet temperature detection. Description of the Drawings

[0016] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0017] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 Schematic flow chart of the first embodiment of the rotor permanent magnet temperature detection method of the present application;

[0019] Figure 2 Schematic structural diagram of the composition of the magnetic suspension motor in the rotor permanent magnet temperature detection method of the present application;

[0020] Figure 3 Schematic flow chart of the second embodiment of the rotor permanent magnet temperature detection method of the present application;

[0021] Figure 4 Schematic structural diagram of the device of the hardware operating environment involved in the rotor permanent magnet temperature detection method in the embodiments of the present application.

[0022] The implementation, functional features and advantages of the present application will be further described in conjunction with the embodiments with reference to the drawings. Detailed implementation manners

[0023] To make the above objects, features and advantages of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present application belong to the scope of protection of the present application.

[0024] Embodiment 1

[0025] The embodiment of the present application provides a rotor permanent magnet temperature detection method, which is applied to a motor. In the first embodiment of the rotor permanent magnet temperature detection method of the present application, the rotor permanent magnet temperature detection method includes:

[0026] Step S10, when the magnetic suspension motor is running, measure the first thermal expansion amount corresponding to the stator of the magnetic suspension motor and measure the second thermal expansion amount corresponding to the body of the magnetic suspension motor;

[0027] Step S20, determine the rotor thermal elongation amount corresponding to the rotor of the magnetic suspension motor according to the first thermal expansion amount and the second thermal expansion amount;

[0028] Step S30, detect the real-time temperature of the rotor permanent magnet on the rotor according to the rotor thermal elongation amount.

[0029] In this embodiment, it should be noted that the magnetic levitation motor can be a high-speed magnetic levitation motor. When the magnetic levitation motor is operating, the temperature of the magnetic levitation motor will increase. If the temperature of the rotor permanent magnet on the rotor is too high, it is easy to occur permanent magnet demagnetization or even irreversible demagnetization and other phenomena. Therefore, it is necessary to monitor the temperature of the rotor permanent magnet in real time. The first thermal expansion amount is the deformation amount of the stator of the magnetic levitation motor due to heat, and this deformation amount can be length or width, etc. For example, assume that the original length of the stator is a, and the length of the stator after heating is b, then the first thermal expansion amount is b - a; the second thermal expansion amount is the deformation amount of the whole machine body part of the magnetic levitation motor due to heat, and this deformation amount can be length or width, etc. The whole machine body part can be composed of the stator and the corresponding part of the rotor. For example, assume that the length of the whole machine body part is c, and the length of the whole machine body part after heating is d, then the second thermal expansion amount is d - c; the rotor thermal elongation amount is the deformation amount of the rotor corresponding to the stator inside the magnetic levitation motor due to heat, and this deformation amount can be length or width, etc. For example, assume that the original length of the rotor is e, and the length of the rotor after heating is f, then the rotor thermal elongation amount is f - e. The rotor mentioned in the embodiment of the present application may not be the whole rotor, but can be the part of the rotor corresponding to the stator in the magnetic levitation motor. For example, assume that there is a stator in the magnetic levitation motor, the length of the stator is A, and the length of the rotor is B, where B is greater than A, that is, the whole rotor has a natural protruding part relative to the stator at the ambient temperature. Thus, at the ambient temperature, the part of the rotor corresponding to the stator in the magnetic levitation motor is axially consistent with the length of the stator, both are A, and radially aligned with the stator. Exemplarily, when it is determined that the two end faces of the stator and the two end faces of the part of the rotor corresponding to the stator are in the same plane, it is determined that the part of the rotor corresponding to the stator in the magnetic levitation motor is aligned with the stator.

[0030] As an example, steps S10 to S20 include: when the magnetic levitation motor is operating, measuring the average temperature of the surface of the machine shell corresponding to the stator of the magnetic levitation motor to obtain the machine shell temperature; determining the thermal expansion amount corresponding to the machine shell temperature according to the correlation between the temperature corresponding to the stator and the thermal expansion amount, to obtain the first thermal expansion amount of the stator corresponding to the magnetic levitation motor; measuring the expansion amount generated by the whole body part corresponding to the stator due to heat through a displacement sensor to obtain the second thermal expansion amount; summing the first thermal expansion amount and the second thermal expansion amount to obtain the elongation amount of the rotor corresponding to the stator inside the magnetic levitation motor due to heat, to obtain the rotor thermal elongation amount; determining the average rotor temperature corresponding to the rotor according to the correlation between the rotor corresponding to the stator inside the magnetic levitation motor and the thermal elongation amount; determining the real-time temperature of the rotor permanent magnet on the rotor according to the average rotor temperature.

[0031] Wherein, the stator includes a preset first displacement measurement position and a preset second displacement measurement position. Measuring the first thermal expansion amount corresponding to the stator of the magnetic levitation motor includes:

[0032] Step A10: Obtain the ambient temperature, the first thermal expansion coefficient corresponding to the stator, and obtain the position spacing length between the preset first displacement measurement position and the preset second displacement measurement position at the ambient temperature;

[0033] Step A20: Measure the average temperature of the housing surface corresponding to the stator to obtain the housing temperature;

[0034] Step A30: Determine the first thermal expansion amount according to the ambient temperature, the housing temperature, the position spacing length, and the first thermal expansion coefficient.

[0035] In this embodiment, it should be noted that the first thermal expansion coefficient is related to the material of the stator part of the magnetic levitation motor. Different types of materials usually have different thermal expansion coefficients. The stator part includes the housing surface of the magnetic levitation motor. The magnetic levitation motor stator is pre-set with a preset first displacement measurement position and a preset second displacement measurement position. A first displacement sensor is arranged at the preset first displacement measurement position, and a second displacement sensor is arranged at the preset second displacement measurement position. As an example, the preset first displacement measurement position and the preset second displacement measurement position can be respectively arranged at the front and rear end edges of the stator part of the magnetic levitation motor. Thus, at the ambient temperature (cold state), the position spacing length between the preset first displacement measurement position and the preset second displacement measurement position can be used as the length of the stator part in the cold state. And the length of the stator part and the corresponding rotor part of the stator part are the same in the cold state. The position spacing length can be used as the original length of the stator part in the cold state, or can also be used as the original length of the rotor part corresponding to the stator part.

[0036] As an example, steps A10 to A30 include: obtaining the current ambient temperature, the first thermal expansion coefficient corresponding to the stator part of the magnetic levitation motor; obtaining the displacement spacing length between the preset first displacement measurement position and the preset second displacement measurement position at the ambient temperature as the cold state length of the stator part; measuring the average temperature of the housing surface in the stator part of the magnetic levitation motor through a temperature sensor to obtain the housing temperature; calculating the temperature change value according to the ambient temperature and the housing temperature; calculating the first thermal expansion amount according to the temperature change value, the position spacing length, and the first thermal expansion coefficient.

[0037] As an example, the formula for calculating the first thermal expansion amount according to the temperature change value, the position spacing length, and the first thermal expansion coefficient is as follows:

[0038] L1 = α1 * L0 * (T1 - T0)

[0039] Wherein, L1 is the first thermal expansion amount, α1 is the first coefficient of thermal expansion, L0 is the position spacing length, T1 is the temperature of the casing, and T0 is the ambient temperature.

[0040] Wherein, measuring the second thermal expansion amount corresponding to the body of the magnetic levitation motor includes:

[0041] Step B10, measuring the first thermal expansion displacement at a preset first displacement measurement position and the second thermal expansion displacement at a preset second displacement measurement position;

[0042] Step B20, detecting the relative displacement between the first displacement measurement position and the second displacement measurement position according to the first thermal expansion displacement and the second thermal expansion displacement, and obtaining the second thermal expansion amount.

[0043] In this embodiment, it should be noted that when the magnetic levitation motor is heated, the magnetic levitation motor will generate thermal expansion amounts at both ends, that is, the magnetic levitation motor will generate displacements in two opposite directions at the preset first displacement measurement position and the preset second displacement measurement position.

[0044] As an example, a first displacement sensor is arranged at the preset first displacement measurement position, a second displacement sensor is arranged at the preset second displacement measurement position, and the silicon steel sheets for measuring displacement in the first displacement sensor and the silicon steel sheets for measuring displacement in the second displacement sensor will both generate displacements as the body of the magnetic levitation motor is heated as a whole, and the relative displacement between the two silicon steel sheets is the thermal expansion amount of the body of the magnetic levitation motor.

[0045] As an example, steps B10 to B20 include: measuring the first thermal expansion displacement generated at the preset first displacement measurement position through the first displacement sensor; measuring the second thermal expansion displacement generated at the preset second displacement measurement position through the second displacement sensor; measuring the relative displacement between the first displacement measurement position and the second displacement measurement position by taking the difference between the first thermal expansion displacement and the second thermal expansion displacement, and taking the relative displacement as the second thermal expansion amount.

[0046] Wherein, after the step of detecting the real-time temperature of the rotor permanent magnet on the rotor according to the thermal elongation amount of the rotor, the rotor permanent magnet temperature detection method further includes:

[0047] Step S40, determining whether the real-time temperature is greater than the preset temperature threshold corresponding to the rotor permanent magnet;

[0048] Step S50, if the real-time temperature is greater than the preset temperature threshold, control the magnetic levitation motor to stop with an over-temperature alarm;

[0049] Step S60, if the real-time temperature is not greater than the preset temperature threshold, keep the magnetic levitation motor in the running state.

[0050] In this embodiment, it should be noted that the preset temperature threshold is a temperature threshold determined according to the demagnetization characteristics of the rotor permanent magnet.

[0051] As an example, steps S40 to S60 include: determining whether the real-time temperature is greater than the preset temperature threshold corresponding to the rotor permanent magnet; if the real-time temperature is greater than the preset temperature threshold, it is determined that the rotor permanent magnet is prone to demagnetization at the current real-time temperature, thereby controlling the magnetic levitation motor to stop with an over-temperature alarm; if the real-time temperature is not greater than the preset temperature threshold, it is determined that the rotor permanent magnet is not prone to demagnetization at the current real-time temperature. Thus, keep the magnetic levitation motor in the running state. It should be noted that once the rotor permanent magnet demagnetizes, the rotating shaft of the magnetic levitation motor will collide with the mechanical bearing during operation, which will cause damage to the entire magnetic levitation motor. The embodiment of the present application realizes the real-time and accurate detection of the temperature of the rotor permanent magnet, and by setting the preset temperature threshold, it can ensure that the rotor permanent magnet of the magnetic levitation motor will not demagnetize during operation, thereby improving the operation safety of the magnetic levitation motor.

[0052] As an example, referring to Figure 2 , Figure 2 is a schematic diagram of the composition structure of the magnetic levitation motor in the embodiment of the present application. Among them, the front displacement sensor is the first displacement sensor, the rear displacement sensor is the second displacement sensor, the position of the front radial magnetic bearing is the preset first displacement measurement position, and the position of the rear radial magnetic bearing is the preset second displacement measurement position.

[0053] In addition, it should be noted that currently, the rotor temperature can also be measured by the back electromotive force method. Specifically, based on the phenomenon that permanent magnets such as alnico, ferrite, and neodymium iron boron show reversible demagnetization within a certain temperature range as the working temperature rises, and the temperature coefficient of the permanent magnet is a fixed value within a certain range. By powering off the motor to obtain the back electromotive force only caused by the permanent magnet, the temperature of the permanent magnet can be measured. However, this method is difficult to monitor the temperature of the rotor permanent magnet in real time during operation, and the limitation of temperature measurement is high. In the embodiment of the present application, the real-time measurement of the temperature of the rotor permanent magnet is realized. Therefore, compared with the back electromotive force method for measuring the temperature of the rotor permanent magnet, the limitation of measuring the temperature of the rotor permanent magnet is reduced.

[0054] Additionally, the rotor temperature monitoring technology can monitor the temperature of the permanent magnet by combining an infrared thermal imager, an infrared thermal sensor, and slip ring signal transmission. However, this method significantly changes the mechanical structure characteristics of the motor and has a high monitoring cost. When using an infrared thermal imager to monitor the temperature of the rotor permanent magnet, it must be monitored under offline conditions. Therefore, the limitations of using this method to measure the temperature of the rotor permanent magnet are also very high. In the embodiments of the present application, by setting a simple displacement sensor and a temperature sensor, the real-time temperature of the rotor permanent magnet can be accurately measured in real time, thus reducing the limitations of measuring the temperature of the rotor permanent magnet.

[0055] The embodiments of the present application provide a method for detecting the temperature of a rotor permanent magnet, that is, when the magnetic levitation motor is running, measuring a first thermal expansion amount corresponding to the stator of the magnetic levitation motor and a second thermal expansion amount corresponding to the body of the magnetic levitation motor; according to the first thermal expansion amount and the second thermal expansion amount, determining a rotor thermal elongation amount corresponding to the rotor of the magnetic levitation motor, achieving the purpose of indirectly measuring the rotor thermal elongation amount by measuring the thermal expansion amount of the stator and the overall thermal expansion amount of the body, and thus according to the principle of thermal expansion of an object, the real-time temperature of the rotor permanent magnet on the rotor can be accurately detected based on the rotor thermal elongation amount, without assuming that the temperatures of the stator and the rotor are equal, but directly detecting the real-time temperature of the rotor permanent magnet based on the thermal elongation amount associated with the rotor, fitting the actual scene when the magnetic levitation motor is running, so overcoming the technical defect in the prior art that it is necessary to estimate temperature-related parameters such as the stator winding resistance and the permanent magnet flux linkage of a permanent magnet synchronous motor based on the assumption that the temperatures of the stator and the rotor are equal, and then using the approximate linear relationship between these parameters and temperature to monitor the temperature of the motor rotor permanent magnet, and improving the accuracy of detecting the temperature of the rotor permanent magnet.

[0056] Embodiment 2

[0057] Further, referring to Figure 3 , in another embodiment of the present application, the same or similar content as in the above Embodiment 1 can be referred to the above introduction and will not be repeated hereinafter. On this basis, the stator includes a preset first displacement measurement position and a preset second displacement measurement position, and the step of detecting the real-time temperature of the rotor permanent magnet on the rotor according to the rotor thermal elongation amount includes:

[0058] Step S31, obtaining the ambient temperature and a second thermal expansion coefficient corresponding to the rotor;

[0059] Step S32, measuring the real-time temperature of the rotor permanent magnet based on the ambient temperature, the position spacing length between the preset first displacement measurement position and the preset second displacement measurement position at the ambient temperature, the second thermal expansion coefficient, and the rotor thermal elongation amount.

[0060] In this embodiment, it should be noted that the second coefficient of thermal expansion is related to the material of the rotor, and different materials usually correspond to different coefficients of thermal expansion.

[0061] As an example, steps S31 to S32 include: obtaining the ambient temperature and the second coefficient of thermal expansion corresponding to the rotor; obtaining the position spacing length between a preset first displacement measurement position and a preset second displacement measurement position at the ambient temperature as the cold state length of the rotor; calculating the real-time average temperature of the rotor according to the ambient temperature, the second coefficient of thermal expansion, the cold state length of the rotor, and the thermal elongation of the rotor, and determining the real-time temperature of the rotor permanent magnet on the rotor according to the real-time average temperature and the temperature gradient of the rotor.

[0062] Among them, the step of measuring the real-time temperature of the rotor permanent magnet according to the ambient temperature, the position spacing length between the preset first displacement measurement position and the preset second displacement measurement position at the ambient temperature, the second coefficient of thermal expansion, and the thermal elongation of the rotor includes:

[0063] Step S321, calculating the average temperature of the rotor corresponding to the rotor according to the ambient temperature, the position spacing length, the second coefficient of thermal expansion, and the thermal elongation of the rotor;

[0064] Step S322, obtaining a temperature conversion coefficient, where the temperature conversion coefficient is determined according to the temperature gradient of the rotor under heating;

[0065] Step S323, determining the real-time temperature of the rotor permanent magnet on the rotor according to the average temperature of the rotor and the temperature conversion coefficient.

[0066] In this embodiment, it should be noted that during the operation of the motor, on the rotor, the temperature of the rotor permanent magnet is usually higher than that of other regions. Therefore, after obtaining the average temperature of the rotor, the average temperature of the rotor should be compensated to obtain a more accurate real-time temperature of the rotor permanent magnet. The temperature conversion coefficient is determined according to the temperature gradient of the rotor under heating and is used to compensate the calculated average temperature of the rotor to obtain the real-time temperature of the rotor permanent magnet. As an example, the temperature conversion coefficient can be the ratio of the average temperature of the entire rotor to the average temperature of the permanent magnet, and the temperature conversion coefficient can be obtained through pre-experiment verification.

[0067] As an example, steps S321 to S323 include: calculating the ratio between the elongation of the rotor due to heat and the position spacing length which is the cold state length of the rotor to obtain a length ratio; determining the rotor temperature change value based on the length ratio and the second coefficient of thermal expansion; calculating the average temperature of the rotor according to the ambient temperature and the rotor temperature change value; obtaining a temperature conversion coefficient, where the temperature conversion coefficient is determined according to the temperature gradient of the rotor under the condition of being heated; and calculating the real-time temperature of the permanent magnet on the rotor according to the average temperature of the rotor and the temperature conversion coefficient.

[0068] As an example, the specific calculation formula for calculating the real-time temperature of the permanent magnet on the rotor is as follows:

[0069]

[0070] Wherein, T2 is the real-time temperature of the permanent magnet on the rotor, T0 is the ambient temperature, L1 is the first thermal expansion amount, L is the second thermal expansion amount, L1 + L is the elongation of the rotor due to heat, L0 is the position spacing length, that is, the cold state length of the rotor, α2 is the second coefficient of thermal expansion, and β is the temperature conversion coefficient.

[0071] The embodiment of the present application provides a method for calculating the real-time temperature of the permanent magnet on the rotor. First, the ambient temperature and the second coefficient of thermal expansion corresponding to the rotor are obtained, and then the average temperature of the rotor corresponding to the rotor is calculated based on the ambient temperature, the cold state length of the rotor, the second coefficient of thermal expansion, and the elongation of the rotor due to heat; a temperature conversion coefficient is obtained, where the temperature conversion coefficient is determined according to the temperature gradient of the rotor under the condition of being heated; and the real-time temperature of the permanent magnet on the rotor is determined based on the average temperature of the rotor and the temperature conversion coefficient. In the embodiment of the present application, while using the elongation of the rotor due to heat to measure the rotor temperature, the real-time situation that the temperature of the permanent magnet on the rotor is higher than that of other regions is fully considered, so a temperature conversion coefficient is preset to compensate the average temperature of the rotor, and a more accurate temperature of the permanent magnet on the rotor is obtained, rather than directly taking the calculated average temperature of the rotor as the temperature of the permanent magnet. The method for calculating the temperature of the permanent magnet on the rotor implemented in the embodiment of the present application is more in line with the actual operation scenario of the magnetic levitation motor, so the accuracy of measuring the temperature of the permanent magnet on the rotor of the magnetic levitation motor is improved.

[0072] Embodiment III

[0073] The present application further provides a device for detecting the temperature of the permanent magnet on the rotor. The device for detecting the temperature of the permanent magnet on the rotor includes:

[0074] A measurement module, configured to measure a first thermal expansion amount corresponding to the stator of the magnetic levitation motor and a second thermal expansion amount corresponding to the body of the magnetic levitation motor when the magnetic levitation motor is operating;

[0075] A determination module, configured to determine a rotor thermal elongation amount corresponding to the rotor of the magnetic levitation motor according to the first thermal expansion amount and the second thermal expansion amount;

[0076] A temperature detection module, configured to detect the real-time temperature of the rotor permanent magnet on the rotor according to the rotor thermal elongation amount.

[0077] Optionally, the stator includes a preset first displacement measurement position and a preset second displacement measurement position, and the measurement module is further configured to:

[0078] Obtain the ambient temperature, the first thermal expansion coefficient corresponding to the stator, and obtain the position spacing length between the preset first displacement measurement position and the preset second displacement measurement position at the ambient temperature;

[0079] Measure the average temperature of the surface of the casing corresponding to the stator to obtain the casing temperature;

[0080] Determine the first thermal expansion amount according to the ambient temperature, the casing temperature, the position spacing length, and the first thermal expansion coefficient.

[0081] Optionally, the measurement module is further configured to:

[0082] Measure a first thermal expansion displacement at the preset first displacement measurement position and a second thermal expansion displacement at the preset second displacement measurement position;

[0083] Detect the relative displacement between the first displacement measurement position and the second displacement measurement position according to the first thermal expansion displacement and the second thermal expansion displacement to obtain the second thermal expansion amount.

[0084] Optionally, the stator includes a preset first displacement measurement position and a preset second displacement measurement position, and the temperature detection module is further configured to:

[0085] Obtain the ambient temperature and the second thermal expansion coefficient corresponding to the rotor;

[0086] Measure the real-time temperature of the rotor permanent magnet according to the ambient temperature, the position spacing length between the preset first displacement measurement position and the preset second displacement measurement position at the ambient temperature, the second thermal expansion coefficient, and the rotor thermal elongation amount.

[0087] Optionally, the temperature detection module is further configured to:

[0088] Calculate the average rotor temperature corresponding to the rotor based on the ambient temperature, the length of the position spacing, the second coefficient of thermal expansion, and the thermal elongation of the rotor.

[0089] Obtain a temperature conversion coefficient, where the temperature conversion coefficient is determined according to the temperature gradient of the rotor under heating conditions.

[0090] Determine the real-time temperature of the rotor permanent magnet on the rotor based on the average rotor temperature and the temperature conversion coefficient.

[0091] Optionally, the preset first displacement measurement position includes the front radial magnetic bearing position, and the second displacement measurement position includes the rear radial magnetic bearing position.

[0092] Optionally, the rotor permanent magnet temperature detection device is further configured to:

[0093] Judge whether the real-time temperature is greater than the preset temperature threshold corresponding to the rotor permanent magnet;

[0094] If the real-time temperature is greater than the preset temperature threshold, control the magnetic levitation motor to alarm and stop due to overheating;

[0095] If the real-time temperature is not greater than the preset temperature threshold, keep the magnetic levitation motor in the running state.

[0096] The rotor permanent magnet temperature detection device provided by this application adopts the rotor permanent magnet temperature detection method in the above embodiment, and solves the technical problem of low accuracy in detecting the temperature of the rotor permanent magnet. Compared with the prior art, the beneficial effects of the rotor permanent magnet temperature detection device provided by the embodiments of this application are the same as those of the rotor permanent magnet temperature detection method provided by the above embodiment, and other technical features in this rotor permanent magnet temperature detection device are the same as the features disclosed in the method of the above embodiment, which will not be elaborated here.

[0097] Embodiment 4

[0098] The embodiments of this application provide an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the rotor permanent magnet temperature detection method in Embodiment 1 above.

[0099] Next, refer to Figure 4, which shows a schematic structural diagram of an electronic device suitable for implementing the embodiments of the present disclosure. The electronic devices in the embodiments of the present disclosure may include, but are not limited to, mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Tablet Computers), PMPs (Portable Multimedia Players), in-vehicle terminals (such as in-vehicle navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 4 The electronic device shown is merely an example and should not impose any limitations on the functions and usage scope of the embodiments of the present disclosure.

[0100] As Figure 4 shown, the electronic device may include a processing device (such as a central processing unit, a graphics processing unit, etc.), which may perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) or the program loaded from the storage device into the random access memory (RAM). In the RAM, various programs and data required for the operation of the electronic device are also stored. The processing device, the ROM, and the RAM are connected to each other through a bus. The input / output (I / O) interface is also connected to the bus.

[0101] Generally, the following systems may be connected to the I / O interface: input devices including, for example, a touch screen, a touchpad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; output devices including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; storage devices including, for example, magnetic tapes, hard disks, etc.; and a communication device. The communication device may allow the electronic device to communicate with other devices wirelessly or wirelesly to exchange data. Although the figure shows an electronic device having various systems, it should be understood that it is not required to implement or include all the shown systems. More or fewer systems may be implemented or included alternatively.

[0102] Specifically, according to the embodiments of the present disclosure, the processes described above with reference to the flowcharts may be implemented as computer software programs. For example, the embodiments of the present disclosure include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program codes for performing the methods shown in the flowcharts. In such an embodiment, the computer program may be downloaded and installed from the network through the communication device, or installed from the storage device, or installed from the ROM. When the computer program is executed by the processing device, the above functions defined in the methods of the embodiments of the present disclosure are performed.

[0103] The electronic device provided by this application adopts the rotor permanent magnet temperature detection method in the above-mentioned embodiment, and solves the technical problem of low accuracy in detecting the temperature of the rotor permanent magnet. Compared with the prior art, the beneficial effects of the electronic device provided by the embodiment of this application are the same as those of the rotor permanent magnet temperature detection method provided by the first embodiment above, and other technical features in this electronic device are the same as those disclosed in the above-mentioned embodiment method, which will not be elaborated here.

[0104] It should be understood that each part of the present disclosure can be implemented by hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0105] Embodiment Five

[0106] This embodiment provides a computer-readable storage medium having computer-readable program instructions stored thereon, and the computer-readable program instructions are used to execute the rotor permanent magnet temperature detection method in the first embodiment above.

[0107] The computer-readable storage medium provided by the embodiment of this application can be, for example, a USB flash drive, but is not limited to an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, system, or device, or any combination of the above. More specific examples of the computer-readable storage medium can include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or combined with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium can be transmitted by any appropriate medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0108] The above computer-readable storage medium can be included in the electronic device; or it can exist separately without being assembled into the electronic device.

[0109] The above computer-readable storage medium stores one or more programs which, when executed by an electronic device, cause the electronic device to: when a magnetic levitation motor is operating, measure a first amount of thermal expansion corresponding to a stator of the magnetic levitation motor and a second amount of thermal expansion corresponding to a body of the magnetic levitation motor; determine a rotor thermal elongation amount corresponding to a rotor of the magnetic levitation motor according to the first amount of thermal expansion and the second amount of thermal expansion; and detect a real-time temperature of a rotor permanent magnet on the rotor according to the rotor thermal elongation amount.

[0110] Computer program code for carrying out operations of the present disclosure may be written in one or more programming languages or combinations thereof. The programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0111] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, may be implemented by a dedicated hardware-based system for performing the specified functions or operations, or may be implemented by a combination of dedicated hardware and computer instructions.

[0112] The modules described in the embodiments of the present disclosure may be implemented in software or in hardware. In some cases, the name of the module does not constitute a limitation on the unit itself.

[0113] The computer-readable storage medium provided by this application stores computer-readable program instructions for executing the above rotor permanent magnet temperature detection method, solving the technical problem of low accuracy in rotor permanent magnet temperature detection. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by the embodiments of this application are the same as those of the rotor permanent magnet temperature detection method provided by the above embodiments, and will not be elaborated here.

[0114] Embodiment Six

[0115] This application also provides a computer program product, including a computer program, and the steps of the rotor permanent magnet temperature detection method as described above are implemented when the computer program is executed by a processor.

[0116] The computer program product provided by this application solves the technical problem of low accuracy in rotor permanent magnet temperature detection. Compared with the prior art, the beneficial effects of the computer program product provided by the embodiments of this application are the same as those of the rotor permanent magnet temperature detection method provided by the above embodiments, and will not be elaborated here.

[0117] As described above, the above are only specific embodiments of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A method for detecting the temperature of a rotor permanent magnet, characterized in that, The rotor permanent magnet temperature detection method includes: When the magnetic levitation motor is running, measuring a first thermal expansion amount corresponding to the stator of the magnetic levitation motor and measuring a second thermal expansion amount corresponding to the body of the magnetic levitation motor; Summing the first thermal expansion amount and the second thermal expansion amount to obtain a rotor thermal elongation amount corresponding to the rotor of the magnetic levitation motor; Detecting the real-time temperature of the rotor permanent magnet on the rotor according to the rotor thermal elongation amount.

2. The rotor permanent magnet temperature detection method according to claim 1, characterized in that The stator includes a preset first displacement measurement position and a preset second displacement measurement position. The step of measuring the first thermal expansion amount corresponding to the stator of the magnetic levitation motor includes: Obtaining the ambient temperature, the first thermal expansion coefficient corresponding to the stator, and obtaining the position spacing length between the preset first displacement measurement position and the preset second displacement measurement position at the ambient temperature; Measuring the average temperature of the housing surface corresponding to the stator to obtain the housing temperature; Determining the first thermal expansion amount according to the ambient temperature, the housing temperature, the position spacing length, and the first thermal expansion coefficient.

3. The rotor permanent magnet temperature detection method according to claim 1, characterized in that The step of measuring the second thermal expansion amount corresponding to the body of the magnetic levitation motor includes: Measuring a first thermal expansion displacement at the preset first displacement measurement position and a second thermal expansion displacement at the preset second displacement measurement position; Detecting the relative displacement between the first displacement measurement position and the second displacement measurement position according to the first thermal expansion displacement and the second thermal expansion displacement to obtain the second thermal expansion amount.

4. The rotor permanent magnet temperature detection method according to claim 1, wherein The stator includes a preset first displacement measurement position and a preset second displacement measurement position. The step of detecting the real-time temperature of the rotor permanent magnet on the rotor according to the rotor thermal elongation amount includes: Obtaining the ambient temperature and the second thermal expansion coefficient corresponding to the rotor; Measuring the real-time temperature of the rotor permanent magnet according to the ambient temperature, the position spacing length between the preset first displacement measurement position and the preset second displacement measurement position at the ambient temperature, the second thermal expansion coefficient, and the rotor thermal elongation amount.

5. The rotor permanent magnet temperature detection method according to claim 4, characterized in that, The step of measuring the real-time temperature of the rotor permanent magnet according to the ambient temperature, the position spacing length between the preset first displacement measurement position and the preset second displacement measurement position at the ambient temperature, the second thermal expansion coefficient, and the rotor thermal elongation amount includes: Calculating the average rotor temperature corresponding to the rotor according to the ambient temperature, the position spacing length, the second thermal expansion coefficient, and the rotor thermal elongation amount; Obtaining a temperature conversion coefficient, where the temperature conversion coefficient is determined according to the temperature gradient of the rotor under heat; Determining the real-time temperature of the rotor permanent magnet on the rotor according to the average rotor temperature and the temperature conversion coefficient.

6. The rotor permanent magnet temperature detection method according to any one of claims 2 to 5, characterized in that, The preset first displacement measurement position includes the front radial magnetic bearing position, and the second displacement measurement position includes the rear radial magnetic bearing position.

7. The rotor permanent magnet temperature detection method according to claim 1, characterized in that After the step of detecting the real-time temperature of the rotor permanent magnet on the rotor according to the rotor thermal elongation amount, the rotor permanent magnet temperature detection method further includes: Determine whether the real-time temperature is greater than the preset temperature threshold corresponding to the rotor permanent magnet; If the real-time temperature is greater than the preset temperature threshold, control the magnetic levitation motor to alarm and stop due to over-temperature; If the real-time temperature is not greater than the preset temperature threshold, keep the magnetic levitation motor in the operating state.

8. A rotor permanent magnet temperature detection device, characterized in that, The rotor permanent magnet temperature detection device includes: A measurement module, configured to measure a first thermal expansion amount corresponding to the stator of the magnetic levitation motor and a second thermal expansion amount corresponding to the body of the magnetic levitation motor when the magnetic levitation motor is running; A determination module, configured to sum the first thermal expansion amount and the second thermal expansion amount to obtain a rotor thermal elongation amount corresponding to the rotor of the magnetic levitation motor; A temperature detection module, configured to detect the real-time temperature of the rotor permanent magnet on the rotor according to the rotor thermal elongation amount.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the steps of the rotor permanent magnet temperature detection method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, A program for implementing the rotor permanent magnet temperature detection method is stored on the computer-readable storage medium, and the program for implementing the rotor permanent magnet temperature detection method is executed by a processor to implement the steps of the rotor permanent magnet temperature detection method according to any one of claims 1 to 7.

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