A method, apparatus, equipment, and medium for estimating the stator temperature of an electric motor.

Abstract

The application provides a kind of motor stator temperature estimation method, comprising: obtaining the working data of motor, working data includes rotational speed data, three-phase current data, cooling water inlet temperature data, cooling water outlet temperature data and cooling water flow data;Three-phase current data is processed, and the copper loss heating power data of stator winding is obtained;Rotational speed data and three-phase current data are processed, and the iron loss heating power data of stator core is obtained;Cooling water inlet temperature data, cooling water outlet temperature data and cooling water flow data are processed, and the heat dissipation power data of cooling water flow under forced convection is obtained;Copper loss heating power data, iron loss heating power data and heat dissipation power data are processed, and motor stator temperature data is obtained.Through the motor stator temperature estimation method disclosed by the application, the actual temperature of the motor can be estimated, and the accuracy is higher.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a method, apparatus, device, and medium for estimating the stator temperature of a motor. Background Technology

[0002] Permanent magnet synchronous motors are widely used in electric vehicles due to their advantages such as high power density, high efficiency, high torque at low speeds, and wide speed range with constant power at high speeds. During operation, the internal temperature of the motor needs to be controlled to prevent damage from overheating. However, due to the limited space within the stator core slots, temperature sensors cannot be placed inside them. If the temperature sensors are placed elsewhere, the measured temperature will deviate significantly from the actual temperature, failing to accurately reflect the motor's true temperature. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method, apparatus, device and medium for estimating the stator temperature of an electric motor. This invention can estimate the actual temperature of the motor with high accuracy.

[0004] To achieve the above and other related objectives, the present invention provides a method for estimating the stator temperature of an electric motor, comprising:

[0005] Acquire the motor's operating data, which includes speed data, three-phase current data, cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data;

[0006] The three-phase current data are processed to obtain the copper loss heating power data of the stator winding;

[0007] The rotational speed data and the three-phase current data are processed to obtain the iron loss heating power data of the stator core;

[0008] The cooling water inlet temperature data, the cooling water outlet temperature data, and the cooling water flow rate data are processed to obtain the cooling water flow rate heat dissipation power data under forced convection.

[0009] The copper loss heating power data, the iron loss heating power data, and the heat dissipation power data are processed to obtain the motor stator temperature data.

[0010] In one embodiment of the present invention, the copper loss heating power data q cu , represented as in,

[0011] I peak This represents the peak current data in the three-phase current data.

[0012] R w (T) represents the resistance value of a certain phase of the stator winding when the temperature is T.

[0013] In one embodiment of the present invention, the R w (T) is represented as R w (T)=R(T0)*(1+α*(T-T0)), where,

[0014] R(T0) represents the resistance value of a certain phase of the stator winding when the temperature is T0.

[0015] T0 represents the preset temperature.

[0016] α represents the correction factor.

[0017] In one embodiment of the present invention, the iron loss heating power data q of the stator core fe , represented as in,

[0018] k1 and k2 represent undetermined coefficients.

[0019] w represents the rotational speed data.

[0020] In one embodiment of the present invention, the motor stator temperature data includes motor stator winding temperature data, motor stator core temperature data, and motor cooling water jacket temperature data.

[0021] In one embodiment of the present invention, the motor stator winding temperature data T w The motor stator core temperature data T m and the motor cooling water jacket temperature data T s The relationship between them is represented as in,

[0022] k represents the kth sampling period.

[0023] T represents the sampling period.

[0024] C1 represents the equivalent heat capacity of the stator winding.

[0025] The equivalent heat capacity of the C2 stator core,

[0026] C3 represents the equivalent heat capacity of the cooling water jacket.

[0027] R wm This represents the equivalent thermal resistance of the stator winding to the stator core slots.

[0028] R ms This represents the equivalent thermal resistance of the stator core to the cooling water jacket.

[0029] q cs This indicates the heat dissipation power data of the cooling system.

[0030] In one embodiment of the present invention, the motor stator winding temperature data T w The motor stator core temperature data T m and the motor cooling water jacket temperature data T s The relationship between them is represented as in,

[0031]

[0032] L -1 This represents the inverse Laplace transform symbol.

[0033] s represents the Laplace variable,

[0034] I represents the identity matrix.

[0035] The present invention also provides a device for estimating the stator temperature of an electric motor, comprising:

[0036] The data acquisition module is used to acquire the motor's operating data, which includes speed data, three-phase current data, cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data.

[0037] The copper loss heating processing module is used to process the three-phase current data to obtain the copper loss heating power data of the stator winding;

[0038] The iron loss heating processing module is used to process the rotation speed data and the three-phase current data to obtain the iron loss heating power data of the stator core.

[0039] The heat dissipation power processing module is used to process the cooling water inlet temperature data, the cooling water outlet temperature data, and the cooling water flow rate data to obtain the heat dissipation power data of the cooling water flow rate under forced convection; and

[0040] The stator temperature estimation module is used to process the copper loss heating power data, the iron loss heating power data, and the heat dissipation power data to obtain the motor stator temperature data.

[0041] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for estimating the stator temperature of the motor.

[0042] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method for estimating the stator temperature of the motor.

[0043] As described above, the present invention provides a method, apparatus, device, and medium for estimating the stator temperature of an electric motor. Based on the heat dissipation power data of the cooling water flow rate under forced convection, the temperature data of the stator winding, the stator core, and the cooling water jacket of the electric motor can be accurately estimated. This can be used for the protection of the motor and ensure that the motor can operate reliably, safely, and stably. Attached Figure Description

[0044] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 The flowchart shown is a method for estimating the stator temperature of an electric motor according to the present invention.

[0046] Figure 2 The diagram shows a method for estimating the stator temperature of an electric motor according to the present invention.

[0047] Figure 3 The diagram shown is a structural schematic of a motor stator temperature estimation device according to the present invention.

[0048] Figure 4 This diagram illustrates the usage state of a motor stator temperature estimation device according to the present invention.

[0049] Figure 5 This is a schematic diagram of the structure of a computer device according to an embodiment of the present invention.

[0050] Figure 6 This is another structural schematic diagram of a computer device according to one embodiment of the present invention.

[0051] Component designation explanation:

[0052] 10. Data acquisition module; 20. Copper loss heat generation processing module; 30. Heat dissipation power processing module; 40. Heat dissipation power processing module; 50. Stator temperature estimation module. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] Please see Figure 1-6 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0055] Please see Figure 1 As shown in the figure, the present invention provides a method for estimating the stator temperature of a motor, which can be applied to motors in vehicles, etc., and can be used to estimate the relevant temperature data of the motor stator windings. Due to the limited internal space of the motor, temperature sensors cannot be placed inside the stator core slots; therefore, they must be placed on the exposed stator windings at the motor ends, or on the external busbars connecting the three-phase stator windings. Because the heating and heat dissipation conditions of the stator windings inside the stator core slots differ greatly from those of the end windings, the measured temperature data of the motor stator windings deviates significantly from the actual temperature data. To accurately obtain the relevant temperature data of the motor stator windings, the measured speed data, three-phase current data, cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data can be processed to estimate the relevant temperature data of the motor stator windings. The method for estimating the motor stator temperature may include the following steps:

[0056] Step S10: Obtain the motor's operating data, including speed data, three-phase current data, cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data.

[0057] In one embodiment of the present invention, the operating data of the motor can be acquired first. This operating data may include the motor's rotational speed, three-phase current, cooling water inlet temperature, cooling water outlet temperature, and cooling water flow rate. The motor's rotational speed can be measured using a speed sensor, but is not limited to this; it can also be measured using a magnetoelectric speed sensor. Alternatively, the frequency of the induced current generated by the rotor of the asynchronous motor cutting magnetic lines of force in a rotating magnetic field can be used as the difference frequency between the motor's rotor frequency and stator voltage frequency. By using an induction coil to sense the motor's leakage flux, the stator voltage frequency signal and the difference frequency signal can be obtained after processing. The synchronous speed of the motor can be obtained from the stator voltage frequency, and the slip speed can be obtained from the difference frequency signal. The difference between the two is the asynchronous speed of the motor.

[0058] In one embodiment of the present invention, the three-phase current data of the motor can be measured using a Hall element current sensor, but is not limited thereto; it can also be measured using an AC / DC zero-flux current sensor or an AC / DC zero-magnetic-flux current sensor. The cooling water inlet temperature data can be measured using a temperature sensor, which can be positioned on one side of the cooling water inlet. The cooling water outlet temperature data can be measured using a temperature sensor, which can be positioned on one side of the cooling water outlet. The cooling water flow rate data can be measured using a flow sensor, which can be positioned on one side of either the cooling water inlet or outlet.

[0059] Step S20: Process the three-phase current data to obtain the copper loss heating power data q of the stator winding. cu , represented as Among them, I peak R represents the peak current data in the three-phase current data. w (T) represents the resistance value of a certain phase stator winding at temperature T. R w (T) is represented as R w (T)=R(T0)*(1+α*(T-T0)), where R(T0) represents the resistance value of a certain phase stator winding at temperature T0, T0 represents the preset temperature, which can be 20℃, 25℃, or 30℃, and α represents the correction coefficient.

[0060] Please see Figure 2 As shown, in one embodiment of the present invention, after obtaining the motor's operating data, the three-phase current data in the operating data can be processed to obtain the peak current data in the three-phase current data. Simultaneously, since the stator windings are multi-phase, and the structure and temperature of the multi-phase stator windings are identical, the copper loss heating power data q of the stator winding can be obtained by processing the resistance value of a certain phase stator winding at temperature T with the peak current data in the three-phase current data. cu , represented as R w (T) can be represented as R w (T)=R(T0)*(1+α*(T-T0)), where R(T0) represents the resistance value of a certain phase stator winding at temperature T0, T0 represents the preset temperature, which can be 20℃, 25℃, or 30℃, and α represents the correction coefficient.

[0061] Step S30: Process the rotational speed data and three-phase current data to obtain the iron loss heating power data of the stator core. This iron loss heating power data includes hysteresis loss data, eddy current loss data, and abnormal loss data. The iron loss heating power data q of the stator core. fe , represented as Where k1 and k2 are undetermined coefficients, which can be obtained by fitting experimental data, and w is the motor speed data.

[0062] Please see Figure 2 As shown, in one embodiment of the present invention, the iron loss heating power data of the stator core can be obtained based on the rotational speed data and three-phase current data. The iron loss heating power data may include hysteresis loss data, eddy current loss data, and abnormal loss data. The iron loss heating power data q of the stator core... fe , can be represented as Where k1 and k2 are undetermined coefficients, which can be obtained by fitting experimental data, and w is the motor speed data. Hysteresis loss data can be the energy consumed by ferromagnetic materials due to hysteresis during repeated magnetization. Hysteresis refers to the phenomenon where the magnetization intensity lags behind the magnetic field strength when the magnetic state of a ferromagnetic material changes; its magnetic flux density B and magnetic field strength H exhibit a hysteresis loop relationship. After one cycle, the hysteresis loss per unit volume of the iron core is proportional to the area of ​​the hysteresis loop. This energy is converted into heat, causing the equipment to heat up and reducing efficiency, thus generating hysteresis loss data. Eddy current loss data can be the loss generated by eddy currents induced in the conductive matrix or structural material of a superconductor in a changing external magnetic field or self-field. Abnormal loss data can be the loss generated when the motor operates under abnormal conditions.

[0063] Step S40: Process the cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data to obtain the cooling water flow rate heat dissipation power data under forced convection. This heat dissipation power data includes the heat dissipation power data of the cooling water carrying away heat and the temperature rise power data of the cooling water being heated. The heat dissipation power data P1 is expressed as P1 = C4 * M r (T c-out -T c-in ), where C4 represents the thermal melting point of the cooling water. M r This indicates cooling water flow rate data. (T) c-out This indicates the temperature data at the cooling water outlet. (T) c-in This indicates the cooling water inlet temperature data. The heating power data P2 is represented as...

[0064] Please see Figure 2As shown, in one embodiment of the present invention, the cooling water flow rate under forced convection can be used to obtain the cooling water heat dissipation power data based on the cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data. The heat dissipation power data can include the heat dissipation power data of the cooling water carrying away heat and the temperature rise power data of the cooling water being heated. The heat dissipation power data can be expressed as the power of heat dissipation from internal motor components, and the temperature rise power data can be expressed as the power of the cooling water temperature increasing due to heat absorption. The heat dissipation power data P1 can be expressed as P1 = C4 * M r (T c-out -T c-in The heating power data P2 can be expressed as: C4 represents the thermal melting point of the cooling water. M r This indicates cooling water flow rate data. (T) c-out This indicates the cooling water outlet temperature data, T c-in This indicates the temperature data at the cooling water inlet.

[0065] Step S50: Process the copper loss heating power data, iron loss heating power data, and heat dissipation power data to obtain the motor stator temperature data, wherein the motor stator temperature data includes the temperature data T of the motor stator winding. w Motor stator core temperature data T m and motor cooling water jacket temperature data T s , Where k represents the kth sampling period. T represents the sampling period. C1 represents the equivalent heat capacity of the stator winding. C2 represents the equivalent heat capacity of the stator core. C3 represents the equivalent heat capacity of the cooling water jacket. R wm R represents the equivalent thermal resistance of the stator winding to the stator core slots. ms This represents the equivalent thermal resistance of the stator core to the cooling water jacket. q cu This represents the copper loss heating power data of the stator winding. q fe This represents the iron loss heating power data of the stator core. q cs This indicates the heat dissipation power data of the cooling system.

[0066] Please see Figure 2 As shown, in one embodiment of the present invention, the motor stator temperature data can be obtained based on the copper loss heating power data, iron loss heating power data, and heat dissipation power data. Specifically, the motor stator temperature data includes the temperature data T of the motor stator winding. w Motor stator core temperature data T m and motor cooling water jacket temperature data T s For the variable to be estimated, according to Kirchhoff's current law, we can obtain: Where, q cu This represents the copper loss heating power data of the stator winding. qfe This indicates the iron loss heating power data of the stator core. C1 represents the equivalent heat capacity of the stator winding. C2 represents the equivalent heat capacity of the stator core. C3 represents the equivalent heat capacity of the cooling water jacket. C4 represents the heat capacity of the cooling water. R wm R represents the equivalent thermal resistance of the stator winding to the stator core slots. ms R represents the equivalent thermal resistance of the stator core to the cooling water jacket. sc This represents the equivalent thermal resistance of the cooling water jacket. T c-out This indicates the temperature data of the cooling water outlet of the motor cooling water jacket. c-in This indicates the temperature data of the cooling water inlet of the motor cooling water jacket. M r This represents the cooling water flow rate data. At this point, the system state equation can be obtained according to formulas (1) to (5), which are expressed as: in, Since parameters a1, a2, C1, C2, and C3 can be determined through experimental data, for a given motor system, these parameters can be considered as known constants. For the copper loss heating power data q of the stator winding... cu Stator core iron loss heating power data q fe and the heat dissipation power data q of the cooling system cs It can be calculated based on the parameters of the cooling system in real time.

[0067] Please see Figure 2 As shown, in one embodiment of the present invention, the heat dissipation power data q of the cooling system cs For the temperature data T of the motor stator winding in the motor stator temperature data w Motor stator core temperature data T m and motor cooling water jacket temperature data T s The impact is significant, therefore, it is necessary to accurately measure the heat dissipation power data q of the cooling system. cs We can first discretize formula (6) to obtain... Where T represents the sampling period, k represents the kth sampling period, and L -1 This represents the inverse Laplace transform symbol, s represents the Laplace variable, and I represents the identity matrix. To reduce the computational load of embedded systems, an approximate discretization method can be used to discretize the system described by equation (6), resulting in... Therefore, q is calculated in real time from the determined parameter values ​​of a1, a2, C1, C2, C3. cu q fe and q csIn the embedded system, the selected sampling time and sampling period are equal to the calling period of the estimation model. According to the recursive formula (7) or (8), the temperature data T of the motor stator winding in the motor stator temperature data can be estimated in real time. w Motor stator core temperature data T m and motor cooling water jacket temperature data T s .

[0068] Please see Figure 2 As shown, in one embodiment of the present invention, the temperature data T of the motor stator winding can be estimated in real time from the motor stator temperature data. w Motor stator core temperature data T m and motor cooling water jacket temperature data T s This limits the operating torque of the motor in both motoring and generating modes. This prevents the motor from operating under overheating conditions, which could lead to the burnout of internal components. For example, the maximum power P of the motor in both motoring and generating modes can be set based on the stator temperature. allow The power reduction setting can be linearly adjusted according to different temperatures. For example, when the stator temperature is below T0, the motor's output power is allowed to operate within its full power range; when the temperature is above T1, the motor's output power is limited to zero. Here, T0 can be 140 degrees Celsius, 150 degrees Celsius, or 155 degrees Celsius. T1 can be 160 degrees Celsius, 170 degrees Celsius, or 180 degrees Celsius, where T1 > T0. Therefore, the maximum power P of the motor in both motoring and generating states is limited based on stator temperature. allow , can be represented as Based on the current actual speed and the limited maximum operating power |P allow First, calculate the range of torque the motor can use, i.e., calculate the usable torque of the motor. Finally, based on the calculated usable torque, limit the motor's operating torque to within the usable torque range.

[0069] As can be seen, in the above scheme, the temperature data of the motor stator winding, the temperature data of the motor stator iron core, and the temperature data of the motor cooling water jacket can be accurately estimated based on the heat dissipation power data of the cooling water flow under forced convection. This can be used for motor protection to ensure that the motor can operate reliably, safely, and stably.

[0070] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0071] Please see Figure 3 and Figure 4As shown, the present invention also provides a device for estimating the stator temperature of a motor, which corresponds one-to-one with the method for estimating the stator temperature of a motor. The device for estimating the stator temperature of a motor may include a data acquisition module 10, a copper loss heating processing module 20, an iron loss heating processing module 30, a heat dissipation power processing module 40, and a stator temperature estimation module 50.

[0072] In one embodiment of the present invention, the data acquisition module 10 can be used to acquire the operating data of the motor, including speed data, three-phase current data, cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data. Specifically, the operating data of the motor can be acquired first, which may include the motor speed data, the motor three-phase current data, the cooling water inlet temperature data of the cooling system, the cooling water outlet temperature data of the cooling system, and the cooling water flow rate data of the cooling system. The motor speed data can be measured by a speed sensor. The motor three-phase current data can be measured by a Hall element current sensor. The cooling water outlet temperature data can be measured by a temperature sensor.

[0073] In one embodiment of the present invention, the copper loss heating processing module 20 can be used to process three-phase current data to obtain copper loss heating power data q of the stator winding. cu , represented as Among them, I peak R represents the peak current data in the three-phase current data. w (T) represents the resistance value of a certain phase stator winding at temperature T. R w (T) is represented as R w (T)=R(T0)*(1+α*(T-T0)), where R(T0) represents the resistance value of a certain phase stator winding at temperature T0, T0 represents the preset temperature, which can be 20℃, 25℃, or 30℃, and α represents the correction coefficient.

[0074] In one embodiment of the present invention, the iron loss heating processing module 30 can be used to process rotational speed data and three-phase current data to obtain iron loss heating power data of the stator core, wherein the iron loss heating power data includes hysteresis loss data, eddy current loss data, and abnormal loss data. The iron loss heating power data q of the stator core. fe , represented as Where k1 and k2 are undetermined coefficients, which can be obtained by fitting experimental data, and w is the motor speed data.

[0075] In one embodiment of the present invention, the heat dissipation power processing module 40 can be used to process cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data to obtain cooling water flow rate heat dissipation power data under forced convection. The heat dissipation power data includes heat dissipation power data for heat carried away by the cooling water and temperature rise power data for the cooling water being heated. The heat dissipation power data P1 is expressed as P1 = C4 * M. r (T c-out -T c-in ), where C4 represents the thermal melting point of the cooling water. M r This indicates cooling water flow rate data. (T) c-out This indicates the temperature data at the cooling water outlet. (T) c-in This indicates the cooling water inlet temperature data. The heating power data P2 is represented as...

[0076] In one embodiment of the present invention, the stator temperature estimation module 50 can be used to process copper loss heating power data, iron loss heating power data, and heat dissipation power data to obtain motor stator temperature data, wherein the motor stator temperature data includes the temperature data T of the motor stator winding. w Motor stator core temperature data T m and motor cooling water jacket temperature data T s , Where k represents the kth sampling period. T represents the sampling period. C1 represents the equivalent heat capacity of the stator winding. C2 represents the equivalent heat capacity of the stator core. C3 represents the equivalent heat capacity of the cooling water jacket. R wm R represents the equivalent thermal resistance of the stator winding to the stator core slots. ms This represents the equivalent thermal resistance of the stator core to the cooling water jacket. q cu This represents the copper loss heating power data of the stator winding. q fe This represents the iron loss heating power data of the stator core. q cs This indicates the heat dissipation power data of the cooling system.

[0077] Specific limitations regarding the motor stator temperature estimation device can be found in the limitations of the intelligent question-and-answer method described above, and will not be repeated here. Each module in the aforementioned motor stator temperature estimation device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the corresponding operations of each module.

[0078] Please see Figure 5As shown, the present invention also provides a computer device, which can be a server. The computer device includes a processor, memory, network interface, and database connected via a system bus. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes non-volatile and / or volatile storage media and internal memory. The non-volatile storage media stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface of the computer device is used to communicate with external clients via a network connection. When the computer program is executed by the processor, it implements the functions or steps of a method for estimating the stator temperature of a motor on the server side.

[0079] Please see Figure 6 As shown, the present invention also provides another computer device, which can be a client. This computer device includes a processor, memory, network interface, display screen, and input device connected via a system bus. The processor of this computer device provides computing and control capabilities. The memory of this computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The network interface of this computer device is used to communicate with an external server via a network connection. When the computer program is executed by the processor, it implements the client-side functions or steps of a method for estimating the stator temperature of a motor.

[0080] In one embodiment of the present invention, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the following steps:

[0081] Acquire the motor's operating data, including speed data, three-phase current data, cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data.

[0082] The three-phase current data is processed to obtain the copper loss heating power data of the stator winding.

[0083] The rotational speed data and three-phase current data are processed to obtain the iron loss heating power data of the stator core. This iron loss heating power data includes hysteresis loss data, eddy current loss data, and abnormal loss data.

[0084] The cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data are processed to obtain the cooling water flow rate heat dissipation power data under forced convection. The heat dissipation power data includes the heat dissipation power data of the cooling water carrying away heat and the temperature rise power data of the cooling water being heated.

[0085] The copper loss heating power data, iron loss heating power data, and heat dissipation power data are processed to obtain the motor stator temperature data, which includes the temperature data of the motor stator winding, the temperature data of the motor stator core, and the temperature data of the motor cooling water jacket.

[0086] In one embodiment of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, wherein the computer program, when executed by a processor, performs the following steps:

[0087] Acquire the motor's operating data, including speed data, three-phase current data, cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data.

[0088] The three-phase current data is processed to obtain the copper loss heating power data of the stator winding.

[0089] The rotational speed data and three-phase current data are processed to obtain the iron loss heating power data of the stator core. This iron loss heating power data includes hysteresis loss data, eddy current loss data, and abnormal loss data.

[0090] The cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow rate data are processed to obtain the cooling water flow rate heat dissipation power data under forced convection. The heat dissipation power data includes the heat dissipation power data of the cooling water carrying away heat and the temperature rise power data of the cooling water being heated.

[0091] The copper loss heating power data, iron loss heating power data, and heat dissipation power data are processed to obtain the motor stator temperature data, which includes the temperature data of the motor stator winding, the temperature data of the motor stator core, and the temperature data of the motor cooling water jacket.

[0092] It should be noted that the functions or steps that can be implemented by the computer-readable storage medium or computer device described above can be referred to the relevant descriptions on the server side and client side in the foregoing method embodiments. To avoid repetition, they will not be described one by one here.

[0093] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0094] In the description of this specification, the references to terms such as "this embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0095] The embodiments of the present invention disclosed above are merely illustrative of the invention. The embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method of estimating the temperature of a motor stator, characterized in that, The method comprises: obtaining working data of the motor, the working data comprising rotation speed data, three-phase current data, cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow data; processing the three-phase current data to obtain copper loss heating power data of the stator winding; processing the rotation speed data and the three-phase current data to obtain iron loss heating power data of the stator core; processing the cooling water inlet temperature data, the cooling water outlet temperature data, and the cooling water flow data to obtain heat dissipation power data of the cooling water flow under forced convection; The copper loss heating power data, the iron loss heating power data and the heat dissipation power data are processed to obtain motor stator temperature data; the motor stator temperature data includes motor stator winding temperature data, motor stator core temperature data and motor cooling water jacket temperature data, the motor stator winding temperature data T w , the motor stator core temperature data T m and the motor cooling water jacket temperature data T s are expressed as Wherein, k represents the kth sampling period, T represents the sampling period, C1 represents the equivalent heat capacity of the stator winding, C2 represents the equivalent heat capacity of the stator core, C3 represents the equivalent heat capacity of the cooling water jacket, R wm represents the equivalent thermal resistance of the stator winding to the stator core tooth slot, R ms represents the equivalent thermal resistance of the stator core to the cooling water jacket, q cs represents the heat dissipation power data of the cooling system.

2. The method of claim 1, wherein, The copper loss heating power data q cu , expressed as wherein, I peak denotes the peak current data in the three-phase current data, R w (T) represents the resistance value of the stator winding of a certain phase at the temperature T.

3. The method of claim 2, wherein, The R w (T) represents R w (T) = R(T0) * (1 + a * (T - T0)), where, R(T0) represents the resistance value of the stator winding of a certain phase when the temperature is T0, T0 represents a preset temperature, α represents a correction coefficient.

4. The method of claim 1, wherein, The iron loss heating power data q of the stator core fe , is expressed as wherein, k1, k2 represent to-be-determined coefficients, w represents the rotation speed data.

5. The method of claim 1, wherein, The relationship between the motor stator winding temperature data T w , the motor stator core temperature data T m , and the motor cooling water jacket temperature data T s is expressed as wherein, L -1 represents the inverse Laplace transform symbol, s represents the Laplace variable, I represents the unit matrix, G(T) and H(T) are the coefficient matrices of the system state equation after discretization, T is the sampling period, u(kT) represents the copper loss heating power data, the iron loss heating power data, and the heat dissipation power data at kT, and A and B represent the coefficient matrices of the system state equation.

6. An apparatus for estimating temperature of a stator of an electric machine, characterized by The application discloses an estimation method for the temperature of a motor stator, and relates to the technical field of motor temperature estimation. The estimation method comprises the following steps: obtaining working data of the motor, the working data comprising rotation speed data, three-phase current data, cooling water inlet temperature data, cooling water outlet temperature data, and cooling water flow data; processing the three-phase current data to obtain copper loss heating power data of the stator winding; processing the rotation speed data and the three-phase current data to obtain iron loss heating power data of the stator core; processing the cooling water inlet temperature data, the cooling water outlet temperature data, and the cooling water flow data to obtain heat dissipation power data of the cooling water flow under forced convection; and 7. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, processing the copper loss heating power data, the iron loss heating power data, and the heat dissipation power data to obtain motor stator temperature data.

8. A computer-readable storage medium storing a computer program, the computer-readable storage medium comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 7. The processor executes the computer program to realize the steps of the estimation method for the temperature of the motor stator. The computer program is executed by the processor to realize the steps of the estimation method for the temperature of the motor stator.

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