CN108458812B - Method and device for acquiring temperature of motor winding - Google Patents

Abstract

The invention discloses a method for acquiring the temperature of a motor winding. The acquisition method includes: calculating the heating coefficient and the cooling coefficient according to the sampling time of the system; calculating the heating temperature according to the heating coefficient; calculating the cooling temperature according to the cooling coefficient; Winding temperature. In addition, the invention also discloses an acquisition device. The obtaining method and obtaining device of the present invention obtain the motor temperature by measuring the voltage, rotational speed and ambient temperature. Since the above parameters can be obtained conveniently, the error of obtaining the motor temperature and the influence of external factors can be reduced. On the other hand, the heating coefficient and cooling coefficient in the present invention are only related to the inherent properties of the motor and the sampling time of the system, but have nothing to do with the operating state of the motor, so when the operating state of the motor changes, it is not necessary to obtain the heating coefficient and cooling coefficient again. .

Description

Obtaining method and obtaining device of motor winding temperature

technical field

The invention relates to the field of motor temperature measurement, in particular to a method and device for acquiring the temperature of a motor winding.

Background technique

In the related art, the motor temperature is generally measured by a sensor. For example, using a contact or non-contact temperature sensor to measure, when using a contact temperature sensor to measure, the temperature sensor is generally set on the winding of the motor, which is likely to cause poor contact between the sensor and the motor due to the rotation of the motor. Large motor temperature acquisition error; when using a non-contact temperature sensor, the non-contact temperature sensor is easily affected by external factors, such as light, etc., thereby increasing the motor temperature acquisition error.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the related art. To this end, embodiments of the present invention provide a method and device for acquiring the temperature of a motor winding.

A method for obtaining a motor winding temperature according to an embodiment of the present invention includes the following steps:

Obtain the winding temperature of the motor at the previous moment, the motor speed at the current moment, the power supply voltage at the current moment, the ambient temperature at the current moment and the system sampling time;

The heating coefficient and cooling coefficient of the motor winding are calculated according to the internal resistance value, surface heat dissipation coefficient, specific heat capacity and mass of the motor at 0°C and the system sampling time, and the heating coefficient is positively correlated with the system sampling time , which is negatively related to the internal resistance, surface heat dissipation coefficient, specific heat capacity and mass of the motor at 0°C, the cooling coefficient is positively related to the sampling time of the system and the surface heat dissipation coefficient, and is related to the specific heat capacity of the motor and negatively correlated with quality;

The heating temperature is obtained by calculating the rotation speed of the motor, the power supply voltage, the winding temperature at the previous moment and the heating coefficient;

Using the winding temperature at the previous moment, the ambient temperature and the cooling coefficient to calculate the cooling temperature; and

According to the winding temperature at the previous moment, the heating temperature and the cooling temperature, the winding temperature of the motor at the current moment is obtained by calculation.

所述降温系数由以下第二公式计算所得：

其中，R₀为所述电机在0℃时的内阻值，c为所述电机的比热容，m为所述电机的质量，μ为所述电机的表面散热系数，△t为所述系统采样时间。In certain embodiments, the heating coefficient is calculated by the following first formula:

The cooling coefficient is calculated by the following second formula:

Among them, R ₀ is the internal resistance of the motor at 0°C, c is the specific heat capacity of the motor, m is the mass of the motor, μ is the surface heat dissipation coefficient of the motor, and Δt is the system sampling time.

In some embodiments, the step of calculating the heating coefficient and cooling coefficient of the motor winding according to the internal resistance value, surface heat dissipation coefficient, specific heat capacity and mass of the motor at 0°C and the system sampling time includes the following steps: step:

Get the model of the motor;

Find the internal resistance value, the preset system sampling time, the preset heating coefficient and the preset cooling coefficient corresponding to the model in the preset database;

Calculate the product of the specific heat capacity and the mass according to the internal resistance value, the preset system sampling time, the preset heating coefficient, the preset cooling coefficient, the first formula and the second formula and said surface heat dissipation coefficient; and

The heating coefficient and the cooling coefficient are calculated according to the system sampling time, the first formula and the second formula.

In some embodiments, the heating temperature is calculated according to the following third formula: T _heating =(UK _t ω) ² (1+0.00426T _i-1 )C _heating , and the cooling temperature is calculated according to the following fourth formula Obtained: T _cooling = (T _i-1 -T _e )C _cooling , where T _heating is the heating temperature, U is the power supply voltage, K _t is the torque coefficient, ω is the motor speed, and T _i-1 is the winding temperature at the previous moment, C _heating is the heating coefficient, T _cooling is the cooling temperature, T _e is the ambient temperature, and C _cooling is the cooling coefficient.

In some embodiments, the step of calculating the winding temperature at the current moment of the motor according to the winding temperature at the previous moment, the heating temperature, and the cooling temperature includes the following steps:

The winding temperature at the current moment is taken as the winding temperature at the previous moment plus the temperature increase temperature minus the cooling temperature temperature.

In some embodiments, the step of calculating the winding temperature at the current moment of the motor according to the winding temperature at the previous moment, the heating temperature, and the cooling temperature includes the following steps:

Determine whether the motor is in a running state;

When the motor is in the running state, the sum of the winding temperature at the previous moment and the temperature rise is taken as the winding temperature at the current moment; and

When the motor is in a stopped state, the difference between the winding temperature at the previous moment and the cooling temperature is used as the winding temperature at the current moment.

An apparatus for acquiring a temperature of a motor winding according to an embodiment of the present invention includes an acquisition module, a first calculation module, a second calculation module, a third calculation module and a fourth calculation module.

The obtaining module is used to obtain the winding temperature of the motor at the previous moment, the motor speed at the current moment, the power supply voltage at the current moment, the ambient temperature at the current moment and the system sampling time.

The first calculation module is configured to calculate the heating coefficient and cooling coefficient of the motor winding according to the internal resistance value, surface heat dissipation coefficient, specific heat capacity and mass of the motor at 0°C and the sampling time of the system, and the heating coefficient It is positively related to the sampling time of the system, negatively related to the internal resistance, surface heat dissipation coefficient, specific heat capacity and mass of the motor at 0°C, and the cooling coefficient is positively related to the sampling time of the system and the surface heat dissipation coefficient , which is negatively related to the specific heat capacity and mass of the motor.

The second calculation module is configured to calculate the temperature increase by using the rotational speed of the motor, the power supply voltage, the winding temperature at the previous moment, and the temperature increase coefficient.

The third calculation module is configured to calculate the cooling temperature by using the winding temperature at the previous moment, the ambient temperature and the cooling coefficient.

The fourth calculation module is configured to calculate the winding temperature of the motor at the current moment according to the winding temperature at the previous moment, the heating temperature and the cooling temperature.

所述降温系数由以下第二公式计算所得：

其中，R₀为所述电机在0℃时的内阻值，c为所述电机的比热容，m为所述电机的质量，μ为所述电机的表面散热系数，△t为所述系统采样时间。In certain embodiments, the heating coefficient is calculated by the following first formula:

The cooling coefficient is calculated by the following second formula:

Among them, R ₀ is the internal resistance of the motor at 0°C, c is the specific heat capacity of the motor, m is the mass of the motor, μ is the surface heat dissipation coefficient of the motor, and Δt is the system sampling time.

In some embodiments, the first calculation module includes an acquisition unit, a search unit, a first calculation unit and a second calculation unit.

The obtaining unit is used for obtaining the model of the motor.

The search unit is configured to search the internal resistance value, the preset system sampling time, the preset heating coefficient and the preset cooling coefficient corresponding to the model in the preset database.

The first calculation unit is configured to calculate the calculated value according to the internal resistance value, the preset system sampling time, the preset heating coefficient, the preset cooling coefficient, the first formula and the second formula. The product of the specific heat capacity and the mass and the surface heat dissipation coefficient.

The second calculation unit is configured to calculate the heating coefficient and the cooling coefficient according to the system sampling time, the first formula and the second formula.

In some embodiments, the heating temperature is calculated according to the following third formula: T _heating =(UK _t ω) ² (1+0.00426T _i-1 )C _heating , and the cooling temperature is calculated according to the following fourth formula Obtained: T _cooling = (T _i-1 -T _e )C _cooling , where T _heating is the heating temperature, U is the power supply voltage, K _t is the torque coefficient, ω is the motor speed, and T _i-1 is the winding temperature at the previous moment, C _heating is the heating coefficient, T _cooling is the cooling temperature, _Te is the ambient temperature, and C _cooling is the cooling coefficient.

In some embodiments, the fourth calculation module is configured to use the winding temperature at the previous moment plus the temperature obtained by subtracting the temperature increase temperature from the temperature decrease temperature as the winding temperature at the current moment.

In some embodiments, the fourth calculation module includes a judgment unit and a third calculation unit.

The judging unit is used for judging whether the motor is in a running state.

The third calculation unit is configured to use the sum of the winding temperature at the previous moment and the heating temperature as the winding temperature at the current moment when the motor is in a running state.

The third calculation unit is configured to use the difference between the winding temperature at the previous moment and the cooling temperature as the winding temperature at the current moment when the motor is in a stopped state.

The acquisition method and acquisition device of the embodiments of the present invention acquire the motor temperature by measuring voltage, rotational speed and ambient temperature. Since the above parameters can be easily acquired, errors in acquiring the motor temperature and the influence of external factors can be reduced.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic flowchart of a method for acquiring a motor winding temperature according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a functional module diagram of a motor winding temperature acquisition device and a motor according to an embodiment of the present invention.

FIG. 3 is another schematic flow chart of a method for acquiring a motor winding temperature according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of functional modules of a first computing module according to an embodiment of the present invention.

FIG. 5 is another schematic flow chart of a method for acquiring a motor winding temperature according to an embodiment of the present invention.

FIG. 6 is another schematic flowchart of a method for acquiring a motor winding temperature according to an embodiment of the present invention.

FIG. 7 is a schematic diagram of another functional module of the motor winding temperature acquisition device and the motor according to the embodiment of the present invention.

Description of main component symbols:

Obtaining device 10, obtaining module 11, first calculating module 13, obtaining unit 132, searching unit 134, first calculating unit 136, second calculating unit 138, second calculating module 15, third calculating module 17, fourth calculating module 19. Judgment unit 194 , third calculation unit 196 , motor 20 , winding 21 .

Detailed ways

Embodiments of the present invention are described in detail below, and embodiments of the present invention are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the present invention, and should not be construed as a limitation of the present invention.

Referring to FIG. 1, the method for obtaining the motor winding temperature according to the embodiment of the present invention includes the following steps:

S11: Obtain the winding temperature of the motor at the previous moment, the motor speed at the current moment, the power supply voltage at the current moment, the ambient temperature at the current moment, and the system sampling time;

S13: Calculate the heating coefficient and cooling coefficient of the motor winding according to the internal resistance value, surface heat dissipation coefficient, specific heat capacity and mass of the motor at 0°C, and the system sampling time. Internal resistance, surface heat dissipation coefficient, specific heat capacity and mass are negatively correlated, cooling coefficient is positively correlated with system sampling time and surface heat dissipation coefficient, and negatively correlated with motor specific heat capacity and mass;

S15: Calculate the heating temperature by using the motor speed, the power supply voltage, the winding temperature at the previous moment and the heating coefficient;

S17: Calculate the cooling temperature using the winding temperature, the ambient temperature and the cooling coefficient at the previous moment; and

S19: Calculate the winding temperature of the motor at the current moment according to the winding temperature, the heating temperature and the cooling temperature at the previous moment.

Referring to FIG. 2 , the apparatus 10 for obtaining the motor winding temperature according to the embodiment of the present invention includes an obtaining module 11 , a first calculation module 13 , a second calculation module 15 , a third calculation module 17 and a fourth calculation module 19 . The obtaining module 11 is used to obtain the winding temperature of the motor at the previous moment, the motor speed at the current moment, the power supply voltage at the current moment, the ambient temperature at the current moment and the system sampling time. The first calculation module 13 is used to calculate the heating coefficient and cooling coefficient of the motor winding according to the internal resistance value, surface heat dissipation coefficient, specific heat capacity and mass of the motor at 0°C, and the system sampling time. At 0°C, the internal resistance, surface heat dissipation coefficient, specific heat capacity and mass are negatively correlated, and the cooling coefficient is positively correlated with the system sampling time and surface heat dissipation coefficient, and negatively correlated with the specific heat capacity and mass of the motor. The second calculation module 15 is configured to calculate the temperature increase by using the motor speed, the power supply voltage, the winding temperature at the previous moment, and the temperature increase coefficient. The third calculation module 17 is used for calculating the cooling temperature by using the winding temperature, the ambient temperature and the cooling coefficient at the previous moment. The fourth calculation module 19 is configured to calculate the current winding temperature of the motor according to the winding temperature, the heating temperature and the cooling temperature at the previous moment.

That is to say, the obtaining method of the embodiment of the present invention can be implemented by the obtaining device 10 of the embodiment of the present invention, wherein step S11 can be realized by the obtaining module 11, step S13 can be realized by the first calculation module 13, and step S15 can be realized by the first calculation module 13. The second calculation module 15 is implemented, the step S17 can be implemented by the third calculation module 17 , and the step S19 can be implemented by the fourth calculation module 19 .

The acquisition method and the acquisition device 10 of the embodiment of the present invention acquire the motor temperature by measuring the voltage, rotational speed and ambient temperature. Since the above parameters can be easily acquired, errors in acquiring the motor temperature and the influence of external factors can be reduced.

Further, the heating coefficient and cooling coefficient in the embodiment of the present invention are only related to the inherent properties of the motor 20 and the sampling time of the system, and have nothing to do with whether the motor is running or not. coefficient and cooling coefficient, which in turn simplifies the steps of the acquisition method.

Specifically, in some embodiments, the inherent properties of the motor 20 may refer to the properties of the motor 20 whether it is running or stopped, such as the internal resistance, mass, specific heat capacity, surface heat dissipation coefficient, torque coefficient, etc. of the motor 20 . The system sampling time can be the sampling period of the motor temperature acquisition. For example, a system sampling time of 1 second means that the motor temperature is acquired every one second; the current moment refers to the corresponding time point when the motor temperature is to be acquired; The time point of the previous system sample at the current moment.

It can be understood that the motor 20 includes the winding 21. Since the temperature of the motor 20 is mainly reflected on the winding 21, the winding temperature in the embodiment of the present invention can be regarded as the motor temperature. When acquiring the motor temperature for the first time, the ambient temperature of the motor 20 may be used as the winding temperature at the previous moment, that is, the motor temperature at the previous moment. In addition, the motor speed can be obtained by a related sensor on the motor 20, such as a Hall sensor; the supply voltage can be obtained by measuring the relevant characteristics of the circuit; the ambient temperature can also be obtained by a related sensor on the motor 20, such as a temperature sensor.

降温系数由以下第二公式计算所得：

其中，R₀为电机20在0℃时的内阻值，c为电机20的比热容，m为电机20的质量，μ为电机20的表面散热系数，△t为系统采样时间。In certain embodiments, the heating coefficient is calculated by the following first formula:

The cooling coefficient is calculated by the following second formula:

Among them, R ₀ is the internal resistance of the motor 20 at 0°C, c is the specific heat capacity of the motor 20, m is the mass of the motor 20, μ is the surface heat dissipation coefficient of the motor 20, and Δt is the system sampling time.

In this way, the heating coefficient and the cooling coefficient can be calculated and obtained according to the first formula and the second formula.

Referring to FIG. 3, in some embodiments, step S13 includes the following steps:

S132: Get the model of the motor 20;

S134: Find the internal resistance value, the preset system sampling time, the preset heating coefficient and the preset cooling coefficient corresponding to the model in the preset database;

S136: Calculate the product of specific heat capacity and mass and the surface heat dissipation coefficient according to the internal resistance value, the preset system sampling time, the preset heating coefficient, the preset cooling coefficient, the first formula and the second formula; and

S138: Calculate the heating coefficient and the cooling coefficient according to the system sampling time, the first formula and the second formula.

Referring to FIG. 4 , in some embodiments, the first calculation module 13 includes an acquisition unit 132 , a search unit 134 , a first calculation unit 136 and a second calculation unit 138 .

The obtaining unit 132 is used to obtain the model of the motor 20 . The search unit 134 is configured to search the preset database for the internal resistance value corresponding to the model, the preset system sampling time, the preset heating coefficient and the preset cooling coefficient. The first calculation unit 136 is configured to calculate the product of the specific heat capacity and mass and the surface heat dissipation coefficient according to the internal resistance value, the preset system sampling time, the preset heating coefficient, the preset cooling coefficient, the first formula and the second formula. The second calculation unit 138 is configured to calculate the heating coefficient and the cooling coefficient according to the system sampling time, the first formula and the second formula.

That is to say, step S132 may be implemented by the acquiring unit 132 , step S134 may be implemented by the searching unit 134 , step S136 may be implemented by the first calculating unit 136 , and step S138 may be implemented by the second calculating unit 138 .

In this way, the heating coefficient and cooling coefficient can be calculated directly according to the sampling time of the system.

Specifically, before the motor 20 leaves the factory or runs, the preset heating coefficient and the preset cooling coefficient can be calibrated according to the preset system sampling time through experiments. For example, the preset system sampling time Δt' can be determined by empirical values. After the preset system sampling time Δt' is determined, in the experiment, the temperature of the motor is increased to a certain temperature and then a cooling experiment is performed. According to the preset system sampling time Use the temperature sensor to measure the winding temperature T _i-1 ' at the previous moment, the winding temperature T _i ' at the current moment and the ambient temperature T _e ', according to the formula T _i '=T _i-1 '-(T _i-1 '- T _e ′)C _cooling ′, so that the preset cooling coefficient C _cooling ′ can be obtained. When the motor temperature is obtained for the first time, T _i-1 ′ is the ambient temperature.

On the other hand, after the above cooling experiment, a heating experiment is carried out. According to the preset system sampling time Δt', the temperature sensor is used to measure the winding temperature T _i-1 ' at the previous moment, the winding temperature T _i ' at the current moment and the ambient temperature T _e ′, at this time according to T _i ′=T _i-1 ′+(UK _t ω) ² (1+0.00426T _i-1 ′)C _heating ′-(T _i-1 ′-T _e ′)C _cooling ′, the power supply voltage U, the motor speed ω and the preset cooling coefficient C _cooling ′ obtained in the experiment are substituted into the formula, and the torque coefficient K _t and the preset heating coefficient C _heating ′ can be calculated.

Then, cm and μ are calculated according to the internal resistance value R ₀ , the preset system sampling time Δt′, the preset heating coefficient C _heating ′, the preset cooling coefficient C _cooling ′, the first formula and the second formula.

When the motor is in normal use, the obtained system sampling times Δt, cm and μ are substituted into the first formula and the second formula, and the corresponding heating coefficient C _heating and cooling coefficient C _cooling can be calculated.

In some embodiments, some inherent properties of the motor 20, such as the product cm of specific heat capacity and mass and the surface heat dissipation coefficient μ, cannot be directly obtained, and the product cm of specific heat capacity and mass and the surface heat dissipation coefficient μ can be calculated through the above experiments, Therefore, when the model of the motor 20 is determined, the heating coefficient C _heating and the cooling coefficient C _cooling can be directly calculated through the system sampling time Δt.

In some embodiments, the inherent properties of the motor 20, such as the product cm of specific heat capacity and mass and the surface heat dissipation coefficient μ are known, then the relevant parameters can be directly substituted into the first formula and the second formula to obtain the heating coefficient and cooling coefficient.

In certain embodiments, the heating temperature is calculated according to the following third formula: T _heating =(UK _t ω) ² (1+0.00426T _i-1 )C _heating , and the cooling temperature is calculated according to the following fourth formula: T _cooling =(T _i-1 -T _e )C _cooling , where T _heating is the heating temperature, U is the supply voltage, K _t is the torque coefficient, ω is the motor speed, T _i-1 is the winding temperature at the previous moment, and C _heating is the heating coefficient, T _cooling is the cooling temperature, T _e is the ambient temperature, and C _cooling is the cooling coefficient.

In this way, the temperature increase temperature and the temperature decrease temperature can be calculated according to the third formula and the fourth formula.

It can be understood that the cooling temperature is related to the difference between the winding temperature and the ambient temperature at the previous moment. The larger the difference, the greater the heat exchange between the motor 20 and the environment, and the faster the motor temperature drops. On the other hand, the heating temperature is related to the supply voltage, torque coefficient, motor speed, winding temperature at the previous moment, and heating coefficient.

Referring to FIG. 5, in some embodiments, step S19 includes the following steps:

S192: The winding temperature at the current moment is taken as the winding temperature at the current moment, plus the temperature of the winding at the previous moment plus the heating temperature and minus the cooling temperature.

In some embodiments, the fourth calculation module 19 is configured to use the winding temperature at the previous moment plus the temperature obtained by adding the heating temperature and subtracting the cooling temperature as the winding temperature at the current moment.

That is to say, step S192 may be implemented by the fourth calculation module 19 .

In this way, the winding temperature at the current moment, that is, the motor temperature, can be truly and accurately calculated according to the actual situation.

Referring to FIG. 6, in some embodiments, step S19 includes the following steps:

S194: determine whether the motor 20 is in a running state;

S196: when the motor 20 is in the running state, use the sum of the winding temperature and the heating temperature at the previous moment as the winding temperature at the current moment; and

S198: When the motor 20 is in a stopped state, the difference between the winding temperature at the previous moment and the cooling temperature is used as the winding temperature at the current moment.

Referring to FIG. 7 , in some embodiments, the fourth calculation module 19 includes a judgment unit 194 and a third calculation unit 196 .

The judging unit 194 is used for judging whether the motor 20 is in a running state. The third calculation unit 196 is used for taking the sum of the winding temperature and the temperature rise temperature at the previous moment as the winding temperature at the current moment when the motor 20 is in the running state, and for taking the sum of the winding temperature at the previous moment The difference between the winding temperature and the cooling temperature is used as the winding temperature at the current moment.

That is to say, step S194 may be implemented by the judgment unit 194 , and steps S196 and S198 may be implemented by the third calculation unit 196 .

In this way, the acquisition process of the motor temperature can be simplified according to the operating state of the motor 20 .

It can be understood that during the operation of the motor 20, the motor temperature rises at this time, and the heating temperature of the motor 20 is far greater than the cooling temperature of the motor 20. Therefore, the cooling temperature of the motor 20 can be ignored, and the winding temperature at the previous moment is used plus the heating temperature. The winding temperature at the current moment can be obtained. When the motor 20 is stopped, the heating temperature of the motor 20 is zero. At this time, the motor temperature drops, and the winding temperature at the current moment can be obtained by subtracting the cooling temperature from the winding temperature at the previous moment.

In the description of the embodiments of the invention, the terms "first" and "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined as "first", "second" may expressly or implicitly include one or more of said features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a It is a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal communication of two components or two components interaction relationship. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" or the like is meant to be used in conjunction with the described embodiments. A particular feature, structure, material or characteristic described by way or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Any description of a process or method in the flowcharts or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing a specified logical function or step of the process , and the scope of the preferred embodiments of the invention includes alternative implementations in which the functions may be performed out of the order shown or discussed, including performing the functions substantially concurrently or in the reverse order depending upon the functions involved, which should It is understood by those skilled in the art to which the embodiments of the present invention pertain.

The logic and/or steps represented in flowcharts or otherwise described herein, for example, may be considered an ordered listing of executable instructions for implementing the logical functions, may be embodied in any computer-readable medium, For use by an instruction execution system, apparatus or apparatus (such as a computer-based system, a system including a processing module, or other system that can fetch instructions from and execute instructions from an instruction execution system, apparatus or apparatus), or in conjunction with such instruction execution system, apparatus or equipment. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport the program for use by or in connection with an instruction execution system, apparatus, or apparatus. More specific examples (non-exhaustive list) of computer readable media include the following: electrical connections with one or more wiring (electronic devices), portable computer disk cartridges (magnetic devices), random access memory (RAM), Read Only Memory (ROM), Erasable Editable Read Only Memory (EPROM or Flash Memory), Fiber Optic Devices, and Portable Compact Disc Read Only Memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the program may be printed, as the paper or other medium may be optically scanned, for example, followed by editing, interpretation, or other suitable medium as necessary process to obtain the program electronically and then store it in computer memory.

It should be understood that various parts of the embodiments of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or a combination of the following techniques known in the art: Discrete logic circuits, application specific integrated circuits with suitable combinational logic gates, Programmable Gate Arrays (PGA), Field Programmable Gate Arrays (FPGA), etc.

Those skilled in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing the relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When executed, includes one or a combination of the steps of a method embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing module, or each unit may exist physically alone, or two or more units may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware, and can also be implemented in the form of software function modules. If the integrated modules are implemented in the form of software functional modules and sold or used as independent products, they may also be stored in a computer-readable storage medium.

The above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, and the like.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and alterations.

Claims (8)

1. The method for acquiring the temperature of the motor winding is characterized by comprising the following steps of:

acquiring the winding temperature of the motor at the previous moment, the motor rotating speed at the current moment, the power supply voltage at the current moment, the environmental temperature at the current moment and the actual system sampling time;

obtaining the model of the motor;

searching an internal resistance value, preset system sampling time, a preset temperature rise coefficient and a preset temperature reduction coefficient of the motor at 0 ℃ corresponding to the model in a preset database;

calculating the product of the specific heat capacity of the motor and the quality of the motor and the surface heat dissipation coefficient of the motor according to the internal resistance value, the preset system sampling time, the preset temperature rise coefficient, the preset temperature drop coefficient, a first formula and a second formula, wherein the first formula is as follows:

the second formula is:

wherein R is₀The internal resistance value is, c is the specific heat capacity of the motor, m is the mass of the motor, mu is the surface heat dissipation coefficient of the motor, and delta t is the system sampling time;

calculating an actual temperature rise coefficient and an actual temperature fall coefficient of the motor winding according to the internal resistance value, the surface heat dissipation coefficient, the specific heat capacity and the mass, the actual system sampling time, the first formula and the second formula, wherein the temperature rise coefficient is positively correlated with the system sampling time and negatively correlated with the internal resistance value of the motor at 0 ℃, the surface heat dissipation coefficient, the specific heat capacity and the mass, the temperature fall coefficient is positively correlated with the system sampling time and the surface heat dissipation coefficient and negatively correlated with the specific heat capacity and the mass, and the actual temperature rise coefficient and the actual temperature fall coefficient are only correlated with the inherent property of the motor and the actual system sampling time and are not correlated with the running state of the motor;

calculating to obtain a heating temperature by using the motor rotating speed, the power supply voltage, the winding temperature at the previous moment and the actual heating coefficient;

calculating to obtain a cooling temperature by using the winding temperature at the previous moment, the environment temperature and the actual cooling coefficient; and

and calculating to obtain the winding temperature of the motor at the current moment according to the winding temperature at the previous moment, the heating temperature and the cooling temperature.

2. The acquisition method according to claim 1, wherein the temperature rise is calculated according to a third formula: t is_heating＝(U-K_tω)²(1+0.00426T_i-1)C_heatingThe cooling temperature is calculated according to the following fourth formula: t is_cooling＝(T_i-1-T_e)C_coolingWherein T is_heatingIs the temperature rise temperature, U is the supply voltage, K_tIs the torque coefficient, omega is the motor speed, T_i-1Is the winding temperature at said previous moment, C_heatingIs the coefficient of temperature rise, T_coolingIs said cooling temperature, T_eIs said ambient temperature, C_coolingIs the cooling coefficient.

3. The method according to claim 1, wherein the step of calculating the winding temperature of the motor at the present time from the winding temperature at the previous time, the temperature-raising temperature, and the temperature-lowering temperature includes the steps of:

and taking the temperature obtained by adding the winding temperature at the previous moment to the temperature obtained by subtracting the cooling temperature from the heating temperature as the winding temperature at the current moment.

4. The method according to claim 1, wherein the step of calculating the winding temperature of the motor at the present time from the winding temperature at the previous time, the temperature-raising temperature, and the temperature-lowering temperature includes the steps of:

judging whether the motor is in a running state or not;

when the motor is in a running state, taking the sum of the winding temperature at the previous moment and the heating temperature as the winding temperature at the current moment; and

and when the motor is in a stop state, taking the difference value between the winding temperature at the previous moment and the cooling temperature as the winding temperature at the current moment.

5. An apparatus for obtaining the temperature of a motor winding, comprising:

the acquisition module is used for acquiring the winding temperature of the motor at the previous moment, the motor rotating speed of the current moment, the power supply voltage of the current moment, the environmental temperature of the current moment and the actual system sampling time;

a first computing module, the first computing module comprising:

an acquisition unit for acquiring a model of the motor;

the searching unit is used for searching the internal resistance value, the preset system sampling time, the preset temperature rise coefficient and the preset temperature reduction coefficient of the motor at 0 ℃ corresponding to the model in a preset database;

the first calculation unit is used for calculating the product of the specific heat capacity of the motor and the quality of the motor and the surface heat dissipation coefficient of the motor according to the internal resistance value, the preset system sampling time, the preset temperature rise coefficient, the preset temperature drop coefficient, a first formula and a second formula, wherein the first formula is as follows:

the second formula is:

wherein R is₀The internal resistance value is, c is the specific heat capacity of the motor, m is the mass of the motor, mu is the surface heat dissipation coefficient of the motor, and delta t is the system sampling time;

a second calculation unit for calculating an actual temperature increase coefficient and an actual temperature decrease coefficient of the motor winding according to the internal resistance value, the surface heat dissipation coefficient, the specific heat capacity and the mass, and the actual system sampling time, the first formula and the second formula, the temperature increase coefficient being positively correlated with the system sampling time, and negatively correlated with the internal resistance value of the motor at 0 ℃, the surface heat dissipation coefficient, the specific heat capacity and the mass, the temperature decrease coefficient being positively correlated with the system sampling time and the surface heat dissipation coefficient, and negatively correlated with the specific heat capacity and the mass, the actual temperature increase coefficient and the actual temperature decrease coefficient being correlated only with the intrinsic property of the motor and the actual system sampling time, and being independent of a state of whether the motor is operating;

the second calculation module is used for calculating the temperature rise temperature by utilizing the motor rotating speed, the power supply voltage, the winding temperature at the previous moment and the actual temperature rise coefficient;

the third calculation module is used for calculating to obtain a cooling temperature by utilizing the winding temperature at the previous moment, the environment temperature and the actual cooling coefficient; and

and the fourth calculation module is used for calculating the winding temperature of the motor at the current moment according to the winding temperature at the previous moment, the heating temperature and the cooling temperature.

6. The acquisition apparatus according to claim 5, wherein the temperature rise is calculated according to a third formula: t is_heating＝(U-K_tω)²(1+0.00426T_i-1)C_heatingThe cooling temperature is calculated according to the following fourth formula: t is_cooling＝(T_i-1-T_e)C_coolingWherein T is_heatingFor the temperature rise, U is the power supplyVoltage, K_tIs the torque coefficient, omega is the motor speed, T_i-1Is the winding temperature at said previous moment, C_heatingIs the temperature rise coefficient T_coolingIs said cooling temperature, T_eIs said ambient temperature, C_coolingIs the cooling coefficient.

7. The obtaining apparatus according to claim 5, wherein the fourth calculating module is configured to use the winding temperature at the previous time plus the temperature obtained by subtracting the temperature decrease temperature from the temperature increase temperature as the winding temperature at the current time.

8. The acquisition apparatus as set forth in claim 5, wherein the fourth calculation module comprises:

the judging unit is used for judging whether the motor is in a running state or not;

a third calculating unit, configured to, when the motor is in an operating state, use a sum of the winding temperature at the previous time and the temperature increase temperature as the winding temperature at the current time; and

and when the motor is in a stop state, taking the difference value between the winding temperature at the previous moment and the cooling temperature as the winding temperature at the current moment.

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