CN114878025A - A method for real-time measurement and calculation of rotor temperature of permanent magnet synchronous motor and related equipment - Google Patents

Abstract

The embodiment of the application provides a method and related equipment for measuring and calculating the temperature of a permanent magnet synchronous motor rotor in real time, which are used for improving the accuracy of measuring and calculating the temperature of the permanent magnet synchronous motor rotor in real time, and the method comprises the following steps: obtaining the voltage value of a back electromotive force line of the permanent magnet synchronous motor under the condition that the initial temperature is T0 at E0 and E0; obtaining back electromotive force line voltage values of the permanent magnet synchronous motor under the conditions of constant rotating speed and constant load operation at an initial temperature T0 of E2 and E2; reading the voltage value of the back electromotive force line of the permanent magnet synchronous motor under the constant rotating speed and constant load operation at the current temperature T1 by using a frequency converter, wherein E3 is E3; the current temperature T1 of the rotor of the permanent magnet synchronous motor is calculated using E0, E2, and E3 according to a preset formula. The embodiment of the application can realize real-time measurement of the rotor temperature of the permanent magnet synchronous motor, and the accuracy of the measurement result is high.

Description

A method for real-time measurement and calculation of rotor temperature of permanent magnet synchronous motor and related equipment

technical field

The embodiments of the present application relate to the field of motors, and in particular, to a method for real-time measurement and calculation of rotor temperature of a permanent magnet synchronous motor and related equipment.

Background technique

Compared with the asynchronous permanent magnet synchronous motor, the permanent magnet synchronous motor has the characteristics of high power density, high efficiency and energy saving. With the implementation of new energy consumption standards for permanent magnet synchronous motors and the setting of dual carbon targets, the application of permanent magnet synchronous motors in various fields of industry has accelerated in breadth and depth. However, the performance of the magnet steel of PMSM varies with temperature, which greatly affects the output performance of PMSM.

When the temperature of the permanent magnet synchronous motor reaches the demagnetization temperature point of the magnetic steel grade, the magnetic steel will be irreversibly demagnetized, so it is very necessary to monitor the rotor temperature of the permanent magnet synchronous motor in real time in industrial applications.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a method for real-time measurement and calculation of the rotor temperature of a permanent magnet synchronous motor and related equipment, which are used to improve the accuracy of real-time measurement and calculation of the rotor temperature of the permanent magnet synchronous motor.

A first aspect of the embodiments of the present application provides a method for real-time measurement and calculation of the rotor temperature of a permanent magnet synchronous motor, including:

Obtain E0, E0 is the back-EMF line voltage value under the no-load operation of the permanent magnet synchronous motor at the initial temperature T0;

Obtain E2, E2 is the back-EMF line voltage value of the permanent magnet synchronous motor under constant speed and constant load operation under the initial temperature T0;

Use the inverter to read E3, E3 is the back-EMF line voltage value of the permanent magnet synchronous motor under the current temperature T1 under constant speed and constant load operation, and T1 is less than the demagnetization temperature of the magnet of the permanent magnet synchronous motor;

According to a preset formula, the current temperature T1 of the rotor of the permanent magnet synchronous motor is calculated using E0, E2 and E3.

In an implementation manner of the first aspect of the embodiment of the present application, the preset formula includes a difference calculation item, and the difference calculation item represents the difference between E3 and E2.

In an implementation manner of the first aspect of the embodiment of the present application, the preset formula includes a ratio calculation item, and the ratio calculation item represents the ratio of the difference to E0.

In an implementation manner of the first aspect of the embodiment of the present application, obtaining E2 specifically includes:

At the initial temperature T0, a constant load is applied to the permanent magnet synchronous motor for a preset time period, and the frequency converter is used to read E2 at a constant speed.

In an implementation manner of the first aspect of the embodiment of the present application, the method further includes:

Obtain the constant error value ΔE generated by the permanent magnet synchronous motor due to temperature change, and the constant error value ΔE is the error of reading the back electromotive force line voltage value of the permanent magnet synchronous motor by using the frequency converter.

That is, to obtain the constant error value ΔE, the constant error value ΔE is the permanent magnet synchronous motor at no load or under constant speed and constant load, using the inverter to read the back EMF line voltage value of the permanent magnet synchronous motor and the real permanent magnet synchronization The error between the back EMF line voltage of the motor. Permanent magnet synchronous motors have a constant error value ΔE due to temperature changes.

In an implementation manner of the first aspect of the embodiment of the present application, obtaining E0 specifically includes:

Use the reverse drag method to obtain E0.

In an implementation manner of the first aspect of the embodiment of the present application, the preset formula is:

where α(Br) is the temperature coefficient of the magnetic steel of the permanent magnet synchronous motor.

A second aspect of the embodiments of the present application provides a device for real-time measurement and calculation of the rotor temperature of a permanent magnet synchronous motor, including:

The first obtaining unit obtains E0, where E0 is the back-EMF line voltage value under the no-load operation of the permanent magnet synchronous motor at the initial temperature T0;

The second obtaining unit is used to obtain E2, where E2 is the back-EMF line voltage value of the permanent magnet synchronous motor under the operation of constant speed and constant load under the initial temperature T0;

The first reading unit is used to read E3 by the frequency converter, E3 is the back-EMF line voltage value of the permanent magnet synchronous motor under the current temperature T1 under constant speed and constant load operation, and T1 is smaller than the magnetic steel of the permanent magnet synchronous motor demagnetization temperature;

The formula calculation unit is used for calculating the current temperature T1 of the rotor of the permanent magnet synchronous motor by using E0, E2 and E3 according to a preset formula.

A third aspect of the embodiments of the present application provides a computer device, including:

Central processing unit, memory, input and output interface and power supply;

The memory is either ephemeral storage storage or persistent storage storage;

The central processing unit is configured to communicate with the memory and execute operations of instructions in the memory to perform the method of the first aspect.

A fourth aspect of the embodiments of the present application provides a computer-readable storage medium, where the computer-readable storage medium includes instructions that, when the instructions are executed on a computer, cause the computer to execute the method of the first aspect.

A fifth aspect of the embodiments of the present application provides a computer program product including instructions, which when the computer program product runs on a computer, causes the computer to execute the method of the first aspect.

A sixth aspect of the embodiments of the present application provides a chip system, the chip system includes at least one processor and a communication interface, the communication interface and the at least one processor are interconnected through a line, and the at least one processor is used to run a computer program or instruction to execute method of the first aspect.

In the embodiment of the present application, when the rotor temperature of the permanent magnet synchronous motor is measured and calculated in real time, the back electromotive force line voltage value E2 of the permanent magnet synchronous motor under the constant speed and constant load operation at the initial temperature T0 is read, taking into account the The error of the back-EMF voltage value of constant speed and constant load is not only calculated based on the initial temperature T0 and the back-EMF line voltage value E0 of the permanent magnet synchronous motor under no-load operation. The parameters considered are more comprehensive and reduce the calculation. error. The embodiment of the present application can realize the real-time measurement of the rotor temperature of the permanent magnet synchronous motor, and the measurement result has high accuracy.

Description of drawings

1 to 2 are various flowcharts of the method for real-time measurement and calculation of the rotor temperature of a permanent magnet synchronous motor according to an embodiment of the present application;

3 is a schematic structural diagram of a device for real-time measuring and calculating the rotor temperature of a permanent magnet synchronous motor according to an embodiment of the present application;

FIG. 4 is a computer device according to an embodiment of the present application.

Detailed ways

According to the existing theory, assuming that the magnetic circuit of the permanent magnet synchronous motor is not saturated, the relationship between the magnetic steel remanence of the permanent magnet synchronous motor and the back EMF is as follows:

E0 is the back-EMF line voltage value measured by the reverse drag method or other methods at the initial temperature T0 of the permanent magnet synchronous motor. Among them, other methods other than the anti-drag method, for example, use a hand crank or other tools to drive the permanent magnet synchronous motor under the bench, and use a measuring instrument such as an oscilloscope to analyze the permanent magnet synchronous motor to obtain E0.

Br0 is the residual magnetism of the permanent magnet synchronous motor magnet at the initial temperature T0. The initial temperature may be normal temperature, such as 20 degrees Celsius, 26 degrees Celsius, etc., which is not specifically limited. Br0 can be obtained by looking up the table according to the grade of the magnetic steel of the permanent magnet synchronous motor, or it can be obtained by measuring with a special instrument.

E1 is the back-EMF line voltage value at the current temperature T1 during the stable operation of the permanent magnet synchronous motor.

Br1 is the residual magnetism at the current temperature T1 during the stable operation of the permanent magnet synchronous motor.

Equation (1) has two unknowns, E1 and Br1.

As shown in FIG. 1 , an embodiment of the present application provides a method for real-time measurement and calculation of the rotor temperature of a permanent magnet synchronous motor, including steps 101 to 104, for improving the accuracy of real-time measurement and calculation of the rotor temperature of the permanent magnet synchronous motor.

101. Obtain E0, where E0 is the back-EMF line voltage value of the permanent magnet synchronous motor under no-load operation at the initial temperature T0.

102. Obtain E2, where E2 is the back-EMF line voltage value of the permanent magnet synchronous motor under the operation of constant speed and constant load under the initial temperature T0.

103. Use the frequency converter to read E3, where E3 is the back-EMF line voltage value of the permanent magnet synchronous motor under the current temperature T1 under constant speed and constant load operation, and T1 is less than the demagnetization temperature of the magnet steel of the permanent magnet synchronous motor.

104. According to a preset formula, use E0, E2 and E3 to calculate the current temperature T1 of the rotor of the permanent magnet synchronous motor.

It should be noted that, there is no timing restriction between step 101 , step 102 and step 103 .

In the embodiment of the present application, when the rotor temperature of the permanent magnet synchronous motor is measured in real time, the back electromotive force line voltage value E2 of the permanent magnet synchronous motor under the operation of constant speed and constant load under the initial temperature T0 is read, taking into account The error of the back-EMF voltage value at constant speed and constant load is not only based on the initial temperature T0, but the back-EMF line voltage value E0 of the permanent magnet synchronous motor under no-load operation is calculated. The parameters considered are more comprehensive and reduce measurement error. The embodiment of the present application can realize the real-time measurement of the rotor temperature of the permanent magnet synchronous motor, and the measurement result has high accuracy.

It should be noted that the back EMF line voltage value E2 of the permanent magnet synchronous motor under constant speed and constant load operation can be read by a frequency converter at the work site, factory or laboratory, or it can be read in the factory or laboratory. Measured with other instruments. The inverter that measures E2 and E3 can be the same inverter.

The embodiment of the present application provides a method for real-time measurement and calculation of the rotor temperature of a permanent magnet synchronous motor, and the theoretical derivation process of the measurement is as follows.

Set the control mode of the inverter to open-loop control, and set the running speed value to make the permanent magnet synchronous motor run at a constant speed. Control the permanent magnet synchronous motor to run at the initial temperature T0, and apply a constant load to the permanent magnet synchronous motor within the preset duration Δt. At this time, read the back EMF line voltage value E2 of the permanent magnet synchronous motor on the inverter, Δt ≤15s.

There is an error in the open-loop control back-EMF algorithm of the inverter. At the initial temperature T0, the back-EMF line voltage value E2 read by the inverter when the permanent magnet synchronous motor is running at a constant speed and a constant load is the same as the real back-EMF line voltage value when the permanent magnet synchronous motor is running at a constant speed and a constant load. E0, there is a constant error value ΔE, where

ΔE=E2−E0 (2).

At the current temperature T1, the real back-EMF line voltage value E1 of the permanent magnet synchronous motor that changes with temperature under the condition of constant speed and constant load operation can be used to use the permanent magnet synchronous motor under the control of the inverter to operate at constant speed and constant load. The difference between the back-EMF line voltage E3 calculated in real time and the constant error value ΔE is obtained, namely

E1 = E3 - ΔE (3).

From formula (3) and formula (2), formula (4) can be obtained as follows

E1=E3+E0-E2 (4)

Putting formula (4) into formula (1), the expression of Br1 can be calculated, and formula (5) is as follows

Br1 is the residual magnetism of the permanent magnet synchronous motor at the current temperature T1 during the constant speed and constant load operation.

Formula (6) expresses the relationship between remanence and temperature, as follows

Brl=Br0.[I+α(Br).(Tl-T0)] (6)

Among them, α(Br) is the temperature coefficient of the magnetic steel of the permanent magnet synchronous motor, which is generally selected from -0.09% to -0.1%.

Formula (7) is obtained by deforming formula (6), as follows

Substitute formula (5) into formula (7) to obtain formula (8) as follows

The embodiments of the present application are used to realize the real-time measurement and calculation of the rotor temperature in the steady state open-loop control of the permanent magnet synchronous motor. Using the open-loop control algorithm of the frequency converter, the back electromotive force value of the permanent magnet synchronous motor is obtained in real time, and the calculation is carried out to obtain the rotor temperature of the permanent magnet synchronous motor, so as to avoid the demagnetization of the permanent magnet synchronous motor magnetic steel.

It should be noted that the formula (8) is not limited to the form given in the embodiments of the present application, and its equivalent deformation can also be adopted, which is not specifically limited here.

As shown in FIG. 2 , an embodiment of the present application provides a method for measuring and calculating the rotor temperature of a permanent magnet synchronous motor in real time, including steps 201 to 207 . Here, the initial temperature is selected as normal temperature, denoted as T0.

201. At normal temperature T0, look up the table according to the magnetic steel grade of the permanent magnet synchronous motor to obtain Br0.

202. Obtain the back electromotive force line voltage value E0 of the permanent magnet synchronous motor by the reverse drag method at the normal temperature T0.

203. Apply a constant speed and a constant load to the permanent magnet synchronous motor within the preset time period Δt under the open-loop control of the inverter at normal temperature T0, and read the back EMF line voltage value obtained under the open-loop control through the inverter E2.

204. At this time, when the temperature is approximately normal temperature T0, there is a constant error value ΔE, ΔE between the back EMF line voltage value read by the inverter and the stable and real back EMF line voltage value E1 when the permanent magnet synchronous motor is running at a constant speed and constant load =E2-E0.

205. The real back-EMF line voltage value E1 that changes with the temperature of the permanent magnet synchronous motor under stable operating conditions can be obtained by using the back-EMF line voltage E3 calculated in real time during the stable and continuous operation of the permanent magnet synchronous motor under the control of the frequency converter obtained at the difference from ΔE

E1=E3-ΔE.

206. The real back-EMF line voltage value E1 of the permanent magnet synchronous motor that changes with temperature under stable operating conditions can be obtained by using the back-EMF line voltage calculated in real time during the stable and continuous operation of the permanent magnet synchronous motor under the control of the frequency converter. The difference between E3 and ΔE is obtained

E1=E3-ΔE=E3-E2+E0.

207. Rotor temperature value of permanent magnet synchronous motor under stable operating conditions

The embodiment of the present application provides a method for real-time measurement of the rotor temperature of a permanent magnet synchronous motor, which is described by taking a certain 15kW permanent magnet synchronous motor as an example.

The rated speed of the permanent magnet synchronous motor is 3600 rpm and the single-layer distributed winding, at this time, α(Br)=-0.095%.

The initial temperature T0 is determined to be 30.1°C, which is obtained by the reverse drag method. When the permanent magnet synchronous motor runs at the rated speed of 3600rpm, the back EMF line voltage E0 of the permanent magnet synchronous motor is 299.2V.

The steps of the reverse drag method are to first use an external power source to accelerate the permanent magnet synchronous motor and maintain it at a specific speed, so that the permanent magnet synchronous motor is in the "generating" mode; then use an oscilloscope or a power analyzer to measure the permanent magnet synchronous motor. Back EMF line voltage E0. The external power source may be another permanent magnet synchronous motor, an internal combustion engine, or the like.

The open-loop control of the inverter is used to control the permanent magnet synchronous motor to run at 3600rpm, and the 15kW permanent magnet synchronous motor is loaded with a load of 40N m within the preset duration Δt of 5s. At this time, the back-EMF line voltage value fed back by the inverter is E2= 310.0V. Constant error value ΔE=E2-E0=310.0V-299.2V=10.8V.

Load this 15kW permanent magnet synchronous motor with a load of 40N m. When the permanent magnet synchronous motor runs at 3600rpm and reaches the steady-state temperature rise, the line back electromotive force E3 = 299.0V obtained by the feedback of the inverter, then the permanent magnet synchronous motor is real at this time. The back EMF line voltage value is E1=E3-ΔE=288.2V.

In order to verify the accuracy of the embodiments of the present application, the back electromotive force line voltage value of the permanent magnet synchronous motor at steady-state temperature measured by the back drag method is 287.5V within 15s. The steady-state temperature is the current temperature T1.

It can be seen from the above that the deviation between the indirectly monitored back EMF value under the steady-state temperature of the permanent magnet synchronous motor and the actual line back EMF value is 0.24%=((288.2-287.5)÷287.5)×100%.

Put E0=299.2V, E3=299.0V, E2=310.0V, α(Br)=-0.095%, T0=30.1 degrees Celsius into formula (8), T1=68.8 degrees Celsius can be obtained. T1 is obtained by calculation, which is the rotor temperature value of the permanent magnet synchronous motor under stable operating conditions.

The back EMF line voltage value may also be referred to as line back EMF.

As shown in FIG. 3 , an embodiment of the present application provides a real-time measurement and calculation device for the rotor temperature of a permanent magnet synchronous motor, including:

The first obtaining unit 301 is used to obtain E0, where E0 is the back-EMF line voltage value under the no-load operation of the permanent magnet synchronous motor at the initial temperature T0;

The second obtaining unit 302 is configured to obtain E2, where E2 is the back-EMF line voltage value of the permanent magnet synchronous motor under constant rotation speed and constant load operation under the initial temperature T0;

The first reading unit 303 is used to read E3 by using a frequency converter, E3 is the back electromotive force line voltage value of the permanent magnet synchronous motor under the constant speed and constant load operation under the current temperature T1, and T1 is smaller than the magnetic field of the permanent magnet synchronous motor. Demagnetization temperature of steel;

The formula calculation unit 304 is configured to calculate the current temperature T1 of the rotor of the permanent magnet synchronous motor by using E0, E2 and E3 according to a preset formula.

In an implementation manner, the second obtaining unit 302 is specifically configured to apply a stable load to the permanent magnet synchronous motor within a preset time period at the initial temperature T0, and use the inverter to read E2 under the load.

The real-time measurement device for rotor temperature of permanent magnet synchronous motor also includes:

The error obtaining unit is used to obtain the constant error value ΔE generated by the permanent magnet synchronous motor due to temperature change, and the constant error value ΔE is the error of using the frequency converter to read the back electromotive force line voltage value of the permanent magnet synchronous motor.

The first obtaining unit 301 is specifically configured to obtain E0 by using the reverse drag method.

As shown in FIG. 4 , an embodiment of the present application further provides a computer device 400, including:

Central processing unit 401, memory 404, input and output interface 403 and power supply 402;

The memory 404 is either ephemeral storage storage or persistent storage storage;

The central processing unit 401 is configured to communicate with the memory 404 and execute the operations of the instructions in the memory 404 to perform the method in the embodiment shown in FIG. 1 to FIG. 2 .

Embodiments of the present application further provide a computer-readable storage medium, where the computer-readable storage medium includes instructions, and when the instructions are executed on a computer, the computer executes the methods in the embodiments shown in FIG. 1 to FIG. 2 .

Embodiments of the present application also provide a computer program product containing instructions, when the computer program product runs on a computer, the computer causes the computer to execute the methods in the embodiments shown in FIG. 1 to FIG. 2 .

The embodiment of the present application also provides a chip system, the chip system includes at least one processor and a communication interface, the communication interface and the at least one processor are interconnected through a line, and the at least one processor is used to run a computer program or instruction to execute FIG. 1 to the method in the embodiment shown in FIG. 2 .

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above may refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The integrated unit, if implemented in the form of a software functional unit and sold or used as an independent product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application can be embodied in the form of software products in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, and the computer software products are stored in a storage medium , including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, removable hard disk, read-only memory (ROM, read-only memory), random access memory (RAM, random access memory), magnetic disk or optical disk and other media that can store program codes.

Claims (10)

1. a permanent magnet synchronous motor rotor temperature measurement method in real time, is characterized in that, comprises: Obtain E0, where described E0 is the back-EMF line voltage value under the no-load operation of the permanent magnet synchronous motor under the initial temperature T0; Obtain E2, where E2 is the back-EMF line voltage value of the permanent magnet synchronous motor under the operation of constant rotational speed and constant load under the initial temperature T0; Use the frequency converter to read E3, the E3 is the back EMF line voltage value of the permanent magnet synchronous motor under the constant speed and the constant load operation at the current temperature T1, and the T1 is less than the permanent magnet synchronous motor. The demagnetization temperature of the magnet; According to a preset formula, the current temperature T1 of the rotor of the permanent magnet synchronous motor is calculated by using the E0, the E2 and the E3. 2. The method for real-time measurement and calculation of the rotor temperature of a permanent magnet synchronous motor according to claim 1, wherein the preset formula comprises a difference calculation item, and the difference calculation item represents the difference between the E3 and the E2 value. 3 . The method for real-time measurement and calculation of the rotor temperature of a permanent magnet synchronous motor according to claim 2 , wherein the preset formula includes a ratio calculation item, and the ratio calculation item represents the ratio of the difference to the E0 . 4 . 4. The real-time method for measuring and calculating the rotor temperature of a permanent magnet synchronous motor according to any one of claims 1 to 3, wherein the obtaining E2 specifically includes: At the initial temperature T0, the constant load is applied to the permanent magnet synchronous motor within a preset time period, and the frequency converter is used to read the E2 at the constant rotational speed. 5. The method for real-time measurement and calculation of the rotor temperature of a permanent magnet synchronous motor according to any one of claims 1 to 3, wherein the method further comprises: The constant error value ΔE generated by the permanent magnet synchronous motor due to temperature changes is obtained, and the constant error value ΔE is the error of using the frequency converter to read the back electromotive force line voltage value of the permanent magnet synchronous motor. 6. The real-time method for measuring and calculating the rotor temperature of a permanent magnet synchronous motor according to any one of claims 1 to 3, wherein the obtaining E0 specifically includes: The E0 is obtained using the reverse drag method. 7. The method for real-time measurement and calculation of the rotor temperature of a permanent magnet synchronous motor according to any one of claims 1 to 3, wherein the preset formula is

Wherein α(Br) is the temperature coefficient of the magnetic steel of the permanent magnet synchronous motor. 8. A real-time measuring and calculating device for permanent magnet synchronous motor rotor temperature, characterized in that, comprising: The first obtaining unit is used to obtain E0, where E0 is the back-EMF line voltage value of the permanent magnet synchronous motor under the no-load operation of the permanent magnet synchronous motor under the initial temperature T0; a second obtaining unit, configured to obtain E2, where E2 is the back-EMF line voltage value of the permanent magnet synchronous motor under the operation of the permanent magnet synchronous motor at a constant rotational speed and a constant load under the initial temperature T0; The first reading unit is used to read E3 by using a frequency converter, and the E3 is the back electromotive force of the permanent magnet synchronous motor under the current temperature T1 when the permanent magnet synchronous motor is running at the constant speed and the constant load Line voltage value, the T1 is less than the demagnetization temperature of the magnetic steel of the permanent magnet synchronous motor; A formula calculation unit, configured to calculate the current temperature T1 of the rotor of the permanent magnet synchronous motor by using the E0, the E2 and the E3 according to a preset formula. 9. A computer equipment, characterized in that, comprising: Central processing unit, memory, input and output interface and power supply; The memory is either ephemeral storage storage or persistent storage storage; The central processing unit is configured to communicate with the memory and execute the operations of the instructions in the memory to perform the method of any one of claims 1-7. 10. A computer-readable storage medium, characterized in that the computer-readable storage medium comprises instructions that, when executed on a computer, cause the computer to perform the method according to any one of claims 1 to 7. method.

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