Motor temperature measurement method, device and system

Abstract

The application discloses a motor temperature measurement method, which comprises the following steps: acquiring motor parameters, wherein the motor parameters comprise a hot spot temperature of a stator, an armature current of a stator winding and an output torque of a rotor; establishing a fuzzy temperature function of the rotor based on the motor parameters, and calculating a fuzzy temperature of the rotor based on the fuzzy temperature function; determining a fuzzy temperature interval of the rotor based on the fuzzy temperature, a temperature interval margin and an influence value of the motor parameters on the rotor temperature; determining a spectrum center wavelength interval of a fiber grating sensor based on the fuzzy temperature interval; and filtering and demodulating a signal reflected by the fiber grating sensor based on the spectrum center wavelength interval, so as to determine a final temperature of the rotor. Through the above arrangement, the measurement accuracy of the rotor temperature can be improved.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a method, device and system for measuring motor temperature. Background Technology

[0002] Motors experience temperature rise during operation, meaning the internal components of the motor heat up. High temperatures in these components can negatively impact motor performance and reduce its lifespan. Therefore, monitoring the temperature of motor components is essential. However, because the motor rotor is rotating, its temperature is typically difficult to measure directly.

[0003] In related technologies, simulation models of stator and rotor temperatures are typically established, and the corresponding rotor temperature is calculated based on the stator temperature using the simulation model. However, measuring the rotor temperature via stator temperature is subject to variations in temperature conduction over time, making real-time and accurate rotor temperature monitoring impossible. Furthermore, related technologies also utilize fiber optic grating sensors to transmit optical signals of different wavelengths based on rotor temperature changes. After demodulation by a demodulator, the rotor temperature is calculated using a wavelength-to-rotor-temperature conversion formula. However, fiber optic grating sensors are susceptible to noise interference, generating interference bands. If these interference bands cannot be removed, accurate rotor temperature cannot be obtained. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this application is to provide a method, device, and system for measuring motor temperature, which has high accuracy in measuring rotor temperature.

[0005] In a first aspect, embodiments of this application provide a method for measuring motor temperature, the method comprising:

[0006] Obtain motor parameters, including stator hot spot temperature, stator winding armature current, and rotor output torque;

[0007] A fuzzy temperature function for the rotor is established based on the motor parameters, and the fuzzy temperature of the rotor is calculated based on the fuzzy temperature function.

[0008] Based on fuzzy temperature, temperature range margin, and the influence of motor parameters on rotor temperature, the fuzzy temperature range of the rotor is determined.

[0009] Based on the fuzzy temperature range, the center wavelength range of the spectrum reflected by the fiber Bragg grating sensor is determined; based on the center wavelength range of the spectrum, the signal reflected by the fiber Bragg grating sensor is filtered and demodulated to determine the final temperature of the rotor.

[0010] In one possible implementation, a fuzzy temperature function for the rotor is established based on motor parameters, including:

[0011] A fuzzy temperature function is established based on the rotor temperature under rated operating conditions and the offset of rotor temperature by changes in hot spot temperature, armature current, and output torque.

[0012] In one possible implementation, the fuzzy temperature range of the rotor is determined based on the fuzzy temperature, temperature range margin, and the influence of motor parameters on rotor temperature, including:

[0013] The temperature range margin is determined based on the thermal resistance between the rotor and stator.

[0014] Determine the derivatives of hot spot temperature, armature current, and output torque, as well as their weights in relation to rotor temperature, to calculate the impact of motor parameters on rotor temperature.

[0015] The fuzzy temperature range is determined based on fuzzy temperature, temperature range margin, and influence value.

[0016] In one possible implementation, the fuzzy temperature range of the rotor is determined based on the fuzzy temperature, temperature range margin, and the influence of motor parameters on rotor temperature, including:

[0017] The sum of the derivative of the hot spot temperature and the product of its weighted effect on the rotor temperature, the derivative of the armature current and the product of its weighted effect on the rotor temperature, and the derivative of the output torque and the product of its weighted effect on the rotor temperature is determined.

[0018] The minimum value of the fuzzy temperature range is calculated by summing the total and the sum of the fuzzy temperatures, and subtracting the temperature range margin.

[0019] In one possible implementation, the fuzzy temperature range of the rotor is determined based on the fuzzy temperature, temperature range margin, and the influence of motor parameters on rotor temperature, including:

[0020] The maximum value of the fuzzy temperature range is calculated based on the sum, the fuzzy temperature, and the sum of the temperature range margin.

[0021] In one possible implementation, the spectral center wavelength range reflected by the fiber Bragg grating sensor is determined based on the fuzzy temperature range, including:

[0022] Calculate the center wavelength of the spectrum reflected by the fiber Bragg grating sensor;

[0023] Based on the fuzzy temperature range, calculate the minimum and maximum offsets of the spectral center wavelength;

[0024] The spectral center wavelength range is calculated based on the spectral center wavelength, minimum offset, and maximum offset.

[0025] In one possible implementation, the signal reflected by the fiber Bragg grating sensor is filtered and demodulated based on the center wavelength range of the spectrum to determine the final temperature of the rotor, including:

[0026] Wavelengths outside the central wavelength range of the spectrum are filtered out by a filter to determine the wavelength distribution within the central wavelength range of the spectrum.

[0027] Based on the wavelength distribution, the actual wavelength of the fiber optic grating sensor affected by rotor temperature is determined;

[0028] Based on the difference between the actual wavelength and the center wavelength of the spectrum, the temperature change of the fiber optic grating sensor affected by the rotor temperature is calculated.

[0029] The actual temperature of the fiber Bragg grating sensor is calculated based on the temperature change, and the actual temperature is the final temperature of the rotor.

[0030] In one possible implementation, the motor temperature measurement method includes:

[0031] Based on the long short-term memory neural network prediction model and the final temperature of the rotor, the temperature change of the rotor within a preset time is predicted.

[0032] Secondly, embodiments of this application provide a computer device including a memory and a storage device. The memory stores program instructions. When the processor executes the program instructions stored in the memory, it implements the aforementioned motor temperature measurement method.

[0033] Thirdly, embodiments of this application provide a motor temperature measurement system, characterized in that it includes a computer device and a fiber Bragg grating sensor. The computer device is used to execute the above-described motor temperature measurement method.

[0034] The aforementioned motor temperature measurement method calculates the fuzzy temperature of the rotor based on motor parameters and a fuzzy temperature function of the rotor. It then determines the fuzzy temperature range of the rotor based on the fuzzy temperature, temperature range margin, and the influence of motor parameters on the rotor temperature. The influence of motor parameters on the rotor temperature can be used to correct the fuzzy temperature range in real time, improving its accuracy. This, in turn, improves the accuracy of the spectral center wavelength range of the fiber Bragg grating sensor reflection calculated based on the fuzzy temperature range. Finally, the signal reflected and transmitted by the fiber Bragg grating sensor is filtered and demodulated based on the spectral center wavelength range to determine the final rotor temperature. This avoids interference from noise and other factors during filtering and demodulation, thereby improving the measurement accuracy of the rotor temperature. Attached Figure Description

[0035] Figure 1 This is a structural block diagram of a computer device according to an embodiment of this application.

[0036] Figure 2 This is a structural block diagram of the motor temperature measurement system according to an embodiment of this application.

[0037] Figure 3 This is a flowchart of a motor temperature measurement method according to an embodiment of this application.

[0038] Figure 4 This is a flowchart illustrating step S2 of the motor temperature measurement method according to an embodiment of this application.

[0039] Figure 5 This is a flowchart illustrating step S3 of the motor temperature measurement method according to an embodiment of this application.

[0040] Figure 6 This is a flowchart illustrating step S33 of the motor temperature measurement method according to an embodiment of this application.

[0041] Figure 7 This is a flowchart illustrating step S4 of the motor temperature measurement method according to an embodiment of this application.

[0042] Figure 8 This is a flowchart illustrating step S5 of the motor temperature measurement method according to an embodiment of this application. Detailed Implementation

[0043] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0044] It should be noted that the terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates at least two. Unless otherwise stated, terms such as "front," "back," "left," "right," "lower," and / or "upper" are for illustrative purposes only and are not limited to a location or spatial orientation. Terms such as "comprising" or "including" indicate that the elements or objects preceding "comprising" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0045] The singular forms “a,” “the,” and “the” used in this application specification and appended claims may also include one or more, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein describes the relationship between related objects, indicating that three relationships may exist, for example, A and / or B, which can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural.

[0046] The method embodiments provided in this example can be executed in computer device 100, fiber optic sensor 200 or similar device. Figure 1 This is a hardware structure block diagram of a computer device 100 that executes a motor temperature measurement method according to an embodiment of this application. Figure 1 As shown, computer device 100 may include one or more ( Figure 1 (Only one is shown in the image) Processor 11 and memory 12.

[0047] The memory 12 stores program instructions, such as a computer program corresponding to a motor temperature measurement method in this embodiment. The processor 11 executes various functional applications and data processing by running the program instructions stored in the memory 12, thereby realizing the aforementioned motor temperature measurement method. The memory 12 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some embodiments, the memory 12 may further include remotely located memories 12 relative to the processor 11, which can be connected to the computer device 100 via a network. Embodiments of the aforementioned network include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0048] Processor 11 is used to execute program instructions stored in memory 12. Processor 11 may be, but is not limited to, a microprocessor (MCU) or a programmable gate array (FPGA). Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the computer device 100 described above. For example, the computer device 100 may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown are illustrated.

[0049] like Figure 2As shown, this application embodiment provides a motor temperature measurement system 200, which includes a computer device 100 and a fiber optic grating sensor 21.

[0050] Computer device 100 is used to perform a method for measuring motor temperature.

[0051] The fiber optic grating sensor 21 can sense external physical quantities, such as temperature, strain, and pressure, by measuring changes in the wavelength of light.

[0052] The final rotor temperature is determined by the cooperation of fiber optic grating sensor 21 and computer device 100, based on the motor temperature measurement method.

[0053] like Figure 3 As shown in the embodiments of this application, a method for measuring motor temperature is provided. In some embodiments, the motor is a permanent magnet motor. If the rotor temperature in the permanent magnet motor is too high, it will cause the permanent magnets in the rotor to demagnetize, thereby affecting the service life of the motor. Therefore, the motor temperature measurement method according to this application can accurately detect the rotor temperature to improve the safety of motor use.

[0054] Specifically, the method for measuring the temperature of the motor includes:

[0055] S1 acquires motor parameters, including stator hot spot temperature, stator winding armature current, and rotor output torque.

[0056] Since the rotor rotates during motor operation, the rotor temperature cannot be directly obtained. However, the stator hot spot temperature, stator winding armature current, and rotor output torque can be directly measured and obtained, and the rotor temperature can be calculated based on these motor parameters.

[0057] In some embodiments, a three-dimensional simulation model of the stator is established to determine the hot spot location of the stator, and the temperature at the hot spot location is measured to obtain the hot spot temperature of the stator.

[0058] S2 establishes a fuzzy temperature function for the rotor based on the motor parameters, and calculates the fuzzy temperature of the rotor based on the fuzzy temperature function.

[0059] The fuzzy temperature function is a temperature modeling method based on fuzzy logic, which is beneficial for obtaining the fuzzy temperature of rotors that is difficult to measure.

[0060] like Figure 4 As shown, step S2, which involves establishing the fuzzy temperature function of the rotor based on the motor parameters, includes:

[0061] S21 establishes a fuzzy temperature function based on the rotor temperature under rated operating conditions and the offset of rotor temperature by changes in hot spot temperature, armature current, and output torque.

[0062] In this embodiment, the rated operating condition is the motor operating condition where no temperature rise occurs. Motor parameters under the rated operating condition and real-time motor parameters during the temperature rise process are measured, and the fuzzy temperature of the rotor is obtained based on a fuzzy temperature function. The fuzzy temperature function is shown in (Formula 1):

[0063] (Formula 1)

[0064] in, The fuzzy temperature of the rotor during the motor's temperature rise process. Rotor temperature under rated operating conditions. This refers to the real-time temperature of the stator hot spot during the motor's temperature rise process. The stator hot spot temperature under rated operating conditions. This refers to the real-time armature current during the motor's temperature rise process. Armature current under rated operating conditions This refers to the real-time output torque during the motor's temperature rise process. The output torque refers to the torque under rated operating conditions. Specify the sub-hotspot temperature offset coefficient. The armature current offset coefficient. This refers to the output torque offset coefficient. This is the stator hot spot temperature offset. This is the armature current offset. This represents the output torque offset. The real-time fuzzy temperature of the rotor is obtained based on a fuzzy temperature function by inputting the real-time temperature of the stator hotspot, the real-time armature current, and the real-time output torque.

[0065] In the embodiments of this application, , and The results were obtained by fitting the data using the controlled variable method under different temperature rise conditions of the motor. For example, by maintaining... and All parameters are under rated operating conditions. Only the armature current is changed, and the rotor temperature can be measured by infrared thermography to fit the relationship between armature current change and rotor temperature, thereby obtaining... .

[0066] Understandable. and The acquisition method is basically the same as The acquisition method is the same, so it will not be repeated here.

[0067] like Figure 3 As shown, the motor temperature measurement method also includes: S3 determining the fuzzy temperature range of the rotor based on fuzzy temperature, temperature range margin, and the influence value of motor parameters on rotor temperature.

[0068] Temperature margin refers to the highest rotor temperature allowed without any change in motor performance. For example, when the motor is a permanent magnet motor, demagnetization will not occur if the rotor is within the temperature margin range. The above settings can obtain a fuzzy temperature range, and based on this fuzzy temperature range, it is beneficial to subsequently determine the final rotor temperature.

[0069] like Figure 5 As shown, step S3 includes:

[0070] S31 determines the temperature range margin based on the thermal resistance between the rotor and stator.

[0071] In this embodiment, the temperature range margin is calculated based on the thermal resistance between the motor rotor and stator, according to the relationship between thermal resistance and temperature range margin. The relationship between thermal resistance and temperature range margin is shown in Formula 2:

[0072] (Formula 2)

[0073] in, This refers to the margin of temperature range; This refers to the safety factor, which can be adjusted according to actual needs. This refers to the thermal resistance between the motor rotor and stator.

[0074] S32 determines the hot spot temperature, armature current, derivatives of output torque, and weights of their influence on rotor temperature in order to calculate the impact of motor parameters on rotor temperature.

[0075] The weight of the derivative of the hot spot temperature on the rotor temperature represents the importance of the stator hot spot temperature change rate on the rotor temperature; the weight of the derivative of the armature current on the rotor temperature represents the importance of the armature current change rate on the rotor temperature; and the weight of the derivative of the output torque on the rotor temperature represents the importance of the output torque change rate on the rotor temperature. These parameters can reflect the changes in motor parameters in real time during motor operation.

[0076] S33 determines the fuzzy temperature range based on fuzzy temperature, temperature range margin, and influence value.

[0077] Due to the difference in temperature conduction aging between the rotor and stator, calculating the rotor temperature solely based on a fuzzy temperature function would result in significant deviations. Therefore, this application calculates the influence of motor parameters on rotor temperature, enabling real-time correction of the temperature range based on motor operating conditions. This improves the accuracy of fuzzy temperature range calculations and enhances the accuracy of obtaining the final rotor temperature.

[0078] like Figure 6As shown, step S33, which involves determining the fuzzy temperature range of the rotor based on fuzzy temperature, temperature range margin, and the influence of motor parameters on rotor temperature, includes:

[0079] S331 determines the sum of the derivatives of the hot spot temperature and their weighted products affecting the rotor temperature, the derivatives of the armature current and their weighted products affecting the rotor temperature, and the derivatives of the output torque and their weighted products affecting the rotor temperature. These settings allow for the acquisition of real-time values ​​showing the impact of motor parameters on rotor temperature during motor operation.

[0080] S332 calculates the minimum value of the fuzzy temperature range based on the sum of the total values ​​and the sum of the fuzzy temperatures, minus the temperature range margin. The formula for calculating the minimum value of the fuzzy temperature range is shown in Formula 3.

[0081] (Formula 3)

[0082] in, The minimum value within the fuzzy temperature range. Temperature range margin, This refers to the rate of real-time change of stator hot spot temperature during the motor's temperature rise process. This refers to the rate of real-time change of armature current during the motor's temperature rise process. This refers to the rate of real-time change of the output torque during the motor's temperature rise process. Specify the weight of the influence of the rate of change of sub-hot spot temperature on rotor temperature. The weight of the effect of the armature current change rate on the rotor temperature. The weight of the effect of the real-time change rate of output torque on rotor temperature.

[0083] In the embodiments of this application, , and The results were obtained by fitting the data using the controlled variable method under different temperature rise conditions of the motor. For example, by maintaining... and All parameters are under rated operating conditions. Only the armature current is changed, and the rotor temperature can be measured using infrared thermography. The measured rotor temperature is substituted into the minimum value of the fuzzy temperature range to fit the relationship between the armature current change and the minimum value of the fuzzy temperature range, thereby obtaining... .

[0084] Understandable. and The acquisition method is basically the same as The acquisition method is the same, so it will not be repeated here.

[0085] In this embodiment of the application, by calculating the influence of motor parameters on rotor temperature in real time, the minimum value of the fuzzy temperature range can be corrected to improve the accuracy of the minimum value of the fuzzy temperature range.

[0086] For example, if the stator hot spot temperature suddenly increases at a certain moment, the corresponding rotor temperature will also suddenly increase. The influence of the stator hot spot temperature on the rotor temperature can be increased. So that It can approximate the rotor temperature that is about to suddenly increase, thereby improving the accuracy of the minimum value of the fuzzy temperature range.

[0087] Step S33, which involves determining the fuzzy temperature range of the rotor based on fuzzy temperature, temperature range margin, and the influence of motor parameters on rotor temperature, further includes:

[0088] S333 calculates the maximum value of the fuzzy temperature range based on the sum of the total, the fuzzy temperature, and the temperature range margin. The formula for calculating the minimum value of the fuzzy temperature range is shown in Formula 4.

[0089] (Formula 4)

[0090] in, The maximum value within the fuzzy temperature range. The fuzzy temperature of the rotor during the motor's temperature rise process is the one mentioned above. , Temperature range margin, This refers to the rate of real-time change of stator hot spot temperature during the motor's temperature rise process. This refers to the rate of real-time change of armature current during the motor's temperature rise process. This refers to the rate of real-time change of the output torque during the motor's temperature rise process. Specify the weight of the influence of the rate of change of sub-hot spot temperature on rotor temperature. The weight of the effect of the armature current change rate on the rotor temperature. The weight of the effect of the real-time change rate of output torque on rotor temperature.

[0091] In this embodiment of the application, by calculating the influence of motor parameters on rotor temperature in real time, the maximum value of the fuzzy temperature range can be corrected, thereby improving the accuracy of the maximum value of the fuzzy temperature range.

[0092] For example, if the stator hot spot temperature suddenly increases at a certain moment, the corresponding rotor temperature will also suddenly increase. The influence of the stator hot spot temperature on the rotor temperature can be increased. So that It can approximate the rotor temperature that is about to suddenly increase, thereby improving the accuracy of the maximum value of the fuzzy temperature range.

[0093] By implementing the above settings, the accuracy of the fuzzy temperature range can be improved, thereby increasing the accuracy of the rotor temperature determined based on the fuzzy temperature range. It should be noted that the order of steps S332 and S333 can be interchanged, and this application does not impose any restrictions on this.

[0094] like Figure 3 As shown, the motor temperature measurement method also includes: S4 determining the spectral center wavelength range reflected by the fiber optic grating sensor 21 based on the fuzzy temperature range.

[0095] The above settings ensure that the central wavelength range of the spectrum obtained from the fuzzy temperature acquisition is not affected by noise or other factors, thereby improving the accuracy of the final rotor temperature obtained.

[0096] like Figure 7 As shown, step S4 includes the following steps:

[0097] S41 calculates the center wavelength of the spectrum reflected by the fiber optic grating sensor 21.

[0098] The fiber Bragg grating sensor 21 is connected to the rotor, and the center wavelength of the fiber Bragg grating sensor 21 under rated motor conditions is calculated based on the formula for calculating the center wavelength of the reflection spectrum of the fiber Bragg grating sensor 21. The formula for calculating the center wavelength of the reflection spectrum of the fiber Bragg grating sensor 21 is shown in (Formula 5):

[0099] (Formula 5)

[0100] in, The center wavelength of the light reflected by the fiber optic grating. The effective refractive index of a fiber Bragg grating. The period of a fiber optic grating.

[0101] S42 calculates the minimum and maximum offsets of the spectral center wavelength based on the fuzzy temperature range.

[0102] When an optical fiber is heated, the effective refractive index of the fiber grating changes due to the thermo-optic effect, and the period of the fiber grating changes due to the thermal expansion effect, which leads to a shift in the center wavelength of the reflection spectrum.

[0103] Specifically, based on the fuzzy temperature range, the minimum and maximum offsets of the spectral center wavelength are obtained according to the formula for calculating the center wavelength shift of the fiber grating. The formula for calculating the center wavelength shift of the fiber grating is shown in Formula 6.

[0104] (Formula 6)

[0105] in, The wavelength shift refers to the amount of wavelength shift at the center wavelength of the spectrum. The center wavelength of the light reflected by the fiber optic grating. The coefficient of thermal expansion of optical fiber. The thermo-optic coefficient of optical fiber. This refers to the temperature rise of the rotor.

[0106] Because the rotor temperature obtained in the fuzzy temperature calculation of this application is a fuzzy temperature range, that is... Therefore, based on the fuzzy temperature range, the temperature rise of the rotor is obtained. .based on The wavelength shift of the center wavelength of the spectrum is calculated. .in, This is the minimum offset of the center wavelength of the spectrum. This represents the maximum offset of the center wavelength of the spectrum.

[0107] S43 calculates the spectral center wavelength range based on the spectral center wavelength, minimum offset, and maximum offset. The minimum value within the spectral center wavelength range is... for and The sum. The maximum value in the central wavelength range of the spectrum. for and sum.

[0108] like Figure 3 As shown, the motor temperature measurement method further includes: S5 filtering and demodulating the signal reflected by the fiber Bragg grating sensor 21 based on the center wavelength range of the spectrum to determine the final rotor temperature. This setting ensures that filtering and demodulating the signal reflected by the fiber Bragg grating sensor 21 based on the center wavelength range of the fuzzy temperature acquisition spectrum is not affected by noise or other factors, thereby improving the accuracy of the obtained final rotor temperature.

[0109] like Figure 8 As shown, step S5 includes the following steps:

[0110] S51 uses a filter to remove wavelengths outside the central wavelength range of the spectrum to determine the wavelength distribution within the central wavelength range. This setting removes interfering wavelengths (those outside the central wavelength range of the spectrum) to obtain the filtered signal corresponding to the ambiguous temperature range. The filtered signal includes the wavelength distribution within the central wavelength range of the spectrum.

[0111] Specifically, the signal input of the fiber Bragg grating sensor 21 is fed into a filter. Based on the center wavelength range of the spectrum, a rectangular window function is established to eliminate interference and output the filtered signal. The rectangular window function is shown in (Equation 7):

[0112] (Formula 7)

[0113] in, Refers to the frequency response of the filter. The center frequency is the reference frequency. The frequency of the input signal, i.e. This refers to the bandwidth of the filter. The passband range of the filter is defined as follows: when the frequency of the signal input to the fiber Bragg grating sensor 21 is within the passband range, it can pass through the filter; when the frequency of the signal input to the fiber Bragg grating sensor 21 is not within the passband range, it cannot pass through the filter. This allows the filter to output a filtered signal, and the wavelength distribution within the center wavelength range of the spectrum can be determined based on the filtered signal.

[0114] In the embodiments of this application, This is the average of the maximum and minimum values ​​in the central wavelength range of the spectrum. The calculation formula is shown in (Formula 8):

[0115] (Formula 8)

[0116] in, It refers to the minimum value in the central wavelength range of the spectrum. It refers to the maximum value of the wavelength range at the center of the spectrum.

[0117] The formula for calculating the bandwidth of the waveguide is shown in (Formula 9):

[0118] (Formula 9)

[0119] in, The coefficient of thermal expansion of optical fiber. The thermo-optic coefficient of optical fiber. The maximum value within the fuzzy temperature range. The minimum value within the fuzzy temperature range. Filter margin.

[0120] S52 determines the actual wavelength of the fiber optic grating sensor 21 affected by rotor temperature based on the wavelength distribution.

[0121] In some embodiments, based on the wavelength distribution, the actual wavelength can be measured using the peak detection method to obtain the actual wavelength of the signal reflected by the fiber optic grating sensor 21 after the rotor temperature rises.

[0122] S53 calculates the temperature change of the fiber optic grating sensor 21 affected by the rotor temperature based on the difference between the actual wavelength and the center wavelength of the spectrum.

[0123] The above settings, the actual wavelength and the center wavelength of the spectrum The difference is the actual offset of the center wavelength of the spectrum, that is, the wavelength drift of the fiber optic grating sensor 21 affected by the rotor temperature. The actual temperature rise of the fiber optic grating sensor 21 is calculated according to (Formula 6), that is, the temperature change of the fiber optic grating sensor 21 affected by the rotor temperature.

[0124] S54 calculates the actual temperature of the fiber optic grating sensor 21 based on the temperature change, and the actual temperature is the final temperature of the rotor.

[0125] With the above settings, the sum of the temperature change and the rotor temperature under rated operating conditions is the final rotor temperature.

[0126] like Figure 3 As shown, the motor temperature measurement method also includes: S6 predicting the temperature change of the rotor within a preset time based on the long short-term memory neural network prediction model and the final temperature of the rotor.

[0127] The Long Short-Term Memory Neural Network Prediction Model is a tool for predicting problems based on time series using deep learning methods. In this application, the Long Short-Term Memory Neural Network Prediction Model can establish logical correlations in time sequence based on the final rotor temperature and motor parameters, thereby predicting the rotor temperature within a preset time period. This enables early warning of rotor temperature and improves the safety of motor operation.

[0128] In summary, this application calculates the fuzzy temperature of the rotor based on motor parameters and a fuzzy temperature function. Based on the fuzzy temperature, temperature range margin, and the influence of motor parameters on rotor temperature, the fuzzy temperature range of the rotor is determined. The influence of motor parameters on rotor temperature can correct the fuzzy temperature range in real time, improving the accuracy of the fuzzy temperature range calculation, thereby improving the accuracy of the spectral center wavelength range of the fiber Bragg grating sensor 21 calculated based on the fuzzy temperature range. The signal reflected by the fiber Bragg grating sensor 21 is filtered and demodulated based on the spectral center wavelength range to determine the final rotor temperature, thus avoiding noise interference signal filtering and demodulation, and further improving the accuracy of the final rotor temperature. Furthermore, a long short-term memory neural network prediction model can predict the rotor temperature to achieve rotor temperature early warning, thereby improving the safety of motor operation.

[0129] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for measuring motor temperature, characterized in that, Obtain motor parameters, including stator hot spot temperature, stator winding armature current, and rotor output torque; A fuzzy temperature function for the rotor is established based on the motor parameters, and the fuzzy temperature of the rotor is calculated based on the fuzzy temperature function. Based on the fuzzy temperature, temperature range margin, and the influence of the motor parameters on the rotor temperature, the fuzzy temperature range of the rotor is determined. Based on the fuzzy temperature range, the spectral center wavelength range reflected by the fiber optic grating sensor is determined; Based on the central wavelength range of the spectrum, the signal reflected by the fiber optic grating sensor is filtered and demodulated to determine the final temperature of the rotor.

2. The motor temperature measurement method according to claim 1, characterized in that, The step of establishing the fuzzy temperature function of the rotor based on the motor parameters includes: The fuzzy temperature function is established based on the rotor temperature under rated operating conditions and the offset of the rotor temperature by changes in the hot spot temperature, the armature current, and the output torque.

3. The motor temperature measurement method according to claim 1, characterized in that, The step of determining the fuzzy temperature range of the rotor based on the fuzzy temperature, temperature range margin, and the influence of the motor parameters on the rotor temperature includes: The temperature range margin is determined based on the thermal resistance between the rotor and the stator. The hot spot temperature, the armature current, the derivative of the output torque, and their weights on the rotor temperature are determined to calculate the influence of the motor parameters on the rotor temperature. The fuzzy temperature range is determined based on the fuzzy temperature, the temperature range margin, and the influence value.

4. The motor temperature measurement method according to claim 3, characterized in that, The step of determining the fuzzy temperature range of the rotor based on the fuzzy temperature, temperature range margin, and the influence of the motor parameters on the rotor temperature includes: The sum of the derivative of the hot spot temperature and the product of its weighted influence on the rotor temperature, the derivative of the armature current and the product of its weighted influence on the rotor temperature, and the derivative of the output torque and the product of its weighted influence on the rotor temperature is determined. The minimum value of the fuzzy temperature range is calculated by subtracting the temperature range margin from the sum of the total and the sum of the fuzzy temperatures.

5. The motor temperature measurement method according to claim 4, characterized in that, The step of determining the fuzzy temperature range of the rotor based on the fuzzy temperature, temperature range margin, and the influence of the motor parameters on the rotor temperature includes: The maximum value of the fuzzy temperature range is calculated based on the sum, the fuzzy temperature, and the sum of the temperature range margin.

6. The motor temperature measurement method according to claim 1, characterized in that, Determining the spectral center wavelength range reflected by the fiber Bragg grating sensor based on the fuzzy temperature range includes: Calculate the center wavelength of the spectrum reflected by the fiber Bragg grating sensor; Based on the fuzzy temperature range, calculate the minimum and maximum offsets of the spectral center wavelength; The spectral center wavelength range is calculated based on the spectral center wavelength, the minimum offset, and the maximum offset.

7. The motor temperature measurement method according to claim 6, characterized in that, Based on the central wavelength range of the spectrum, the signal reflected by the fiber Bragg grating sensor is filtered and demodulated to determine the final temperature of the rotor, including: Wavelengths outside the central wavelength range of the spectrum are filtered out by a filter to determine the wavelength distribution within the central wavelength range of the spectrum. Based on the wavelength distribution, the actual wavelength of the fiber optic grating sensor affected by the rotor temperature is determined; Based on the difference between the actual wavelength and the center wavelength of the spectrum, the temperature change of the fiber optic grating sensor affected by the rotor temperature is calculated. The actual temperature of the fiber optic grating sensor is calculated based on the temperature change, and the actual temperature is the final temperature of the rotor.

8. The motor temperature measurement method according to claim 1, characterized in that, The method includes: Based on the long short-term memory neural network prediction model and the final temperature of the rotor, the temperature change of the rotor within a preset time period is predicted.

9. A computer device, comprising: include: A memory, wherein the memory stores program instructions; The processor, when executing the program instructions stored in the memory, implements the motor temperature measurement method according to any one of claims 1 to 8.

10. An electrical machine temperature measurement system, characterized by, include: Computer equipment, said computer equipment being used to perform the motor temperature measurement method as described in any one of claims 1 to 8; The fiber Bragg grating sensor as described in any one of claims 1 to 8.

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