Method and system for determining rotor zero position of three-phase permanent magnet motor based on D-axis vector

Abstract

The present invention discloses a method and system for determining the rotor zero position of a three-phase permanent magnet motor based on a D-axis vector, the method comprising: obtaining the rotor zero position in a memory and reading the current position of the rotor for the first time; outputting a D-axis voltage vector pointing to the current position of the rotor according to the rotor zero position and the current position of the rotor read for the first time, so that the rotor is fixed at the current position; reading the current position of the rotor at a certain frequency interval, and obtaining the angular velocity by difference, and when the angular velocity is less than a preset value, reading the current position of the rotor for the second time; obtaining the rotor zero position correction amount according to the current position of the rotor read for the second time and the first time, obtaining the corrected rotor zero position in combination with the rotor zero position in the memory, and storing the corrected rotor zero position in the memory. The present invention simplifies the debugging steps of the three-phase permanent magnet motor, and after the rotor zero position is accurately positioned, the rotor will not rotate again when the motor is restarted again, thereby improving its startup speed and production debugging efficiency, and having good adaptability and reliability.

Description

Technical Field

[0001] The present invention relates to the field of inertial navigation, and in particular to a method and system for determining the zero position of a rotor of a three-phase permanent magnet motor based on a D-axis vector. Background Art

[0002] Modulated inertial navigation is a type of inertial navigation proposed to deal with problems such as gyro drift, hoping to offset the drift characteristics of this device through the symmetrical movement of the inertial navigation. Therefore, modulated inertial navigation has high requirements on the control performance of the axis system.

[0003] Three-phase permanent magnet synchronous motors are widely used in modulated inertial navigation due to their high energy density and other characteristics, but the control of three-phase motors is relatively complex. When controlling them, it is necessary to ensure that the voltage vector is at a certain angle relative to the rotor to ensure control efficiency and effect. Therefore, it is particularly important to obtain the correct initial position of the rotor, that is, the rotor zero position.

[0004] There are two main methods for rotor zero-position positioning in the existing technology: one is to output a 1-0-0 vector and then directly measure the angle, but this method will cause the shaft system to rotate an angle, and this unpredictable rotation limits its application scenarios; the other is the high-frequency injection method, which has complex steps and low identification accuracy. Summary of the invention

[0005] In view of the problems that the rotor zero position parameters of the three-phase permanent magnet motor in each set of inertial navigation equipment are different and the equipment production and debugging steps are complicated, the present invention proposes a three-phase permanent magnet motor rotor zero position determination method and system based on D-axis vector with good adaptability, simple steps and high reliability.

[0006] To this end, the technical solution adopted in the present invention is:

[0007] A method for determining a rotor zero position of a three-phase permanent magnet motor based on a D-axis vector is provided, the method comprising:

[0008] Get the rotor zero position stored in the memory and read the current position of the rotor for the first time;

[0009] Outputting a D-axis voltage vector pointing to the current position of the rotor read for the first time according to the rotor zero position and the current position of the rotor read for the first time, so that the rotor is fixed at the current position of the rotor read for the first time;

[0010] The current position of the rotor is read at a certain frequency interval, and the angular velocity is obtained by differentiating the current position of the rotor. When the angular velocity is less than the preset value, the current position of the rotor is read for the second time.

[0011] The rotor zero position correction amount is obtained according to the rotor current position read for the second time and the rotor current position read for the first time, and the corrected rotor zero position is obtained in combination with the rotor zero position in the memory, and the corrected rotor zero position is stored in the memory.

[0012] According to the above solution, the D-axis voltage vector includes the D-axis voltage direction and the D-axis voltage modulus.

[0013] According to the above scheme, the D-axis voltage direction is calculated by the rotor zero position and the current rotor position read for the first time; and the D-axis voltage modulus is obtained by setting.

[0014] According to the above scheme, the rotor zero position correction amount is obtained by subtracting the rotor current position read for the second time from the rotor current position read for the first time.

[0015] According to the above scheme, the corrected rotor zero position is obtained by adding the rotor zero position correction amount to the rotor zero position in the memory.

[0016] According to the above scheme, the current position of the rotor is read by a high-precision position sensor.

[0017] A three-phase permanent magnet motor rotor zero position determination system based on a D-axis vector is provided, the system comprising:

[0018] A reading module, used to obtain the rotor zero position stored in the memory and read the current position of the rotor for the first time;

[0019] A vector control module is used to output a D-axis voltage vector pointing to the current position of the rotor read for the first time according to the rotor zero position and the current position of the rotor read for the first time, so that the rotor is fixed at the current position of the rotor read for the first time;

[0020] A judgment module is used to read the current position of the rotor at a certain frequency interval, and to obtain the angular velocity by differentiating the current position of the rotor. When the angular velocity is less than a preset value, the current position of the rotor is read for a second time.

[0021] The correction module is used to obtain a rotor zero position correction value according to the rotor current position read for the second time and the rotor current position read for the first time, obtain a corrected rotor zero position in combination with the rotor zero position in the memory, and store the corrected rotor zero position in the memory.

[0022] According to the above scheme, the vector control module is specifically used to calculate the D-axis voltage direction based on the rotor zero position and the current rotor position read for the first time, and set the D-axis voltage modulus, and combine the D-axis voltage direction and the D-axis voltage modulus to output the D-axis voltage vector pointing to the current rotor position read for the first time, so that the rotor is fixed at the current rotor position read for the first time.

[0023] According to the above scheme, the correction module is specifically used to subtract the current rotor position read for the second time from the current rotor position read for the first time to obtain a rotor zero position correction amount, then add the rotor zero position in the memory to the rotor zero position correction amount to obtain a corrected rotor zero position, and store the corrected rotor zero position in the memory.

[0024] A three-phase permanent magnet motor is provided, which uses the three-phase permanent magnet motor rotor zero position determination method based on the D-axis vector described above to perform zero position positioning of the three-phase permanent magnet motor rotor.

[0025] The beneficial effects of the present invention are as follows: the present invention outputs a D-axis voltage vector according to the rotor zero position stored in the memory in the three-phase permanent magnet motor to fix the rotor, reads the rotor position when the rotor angular velocity is less than a certain preset value, thereby obtaining the rotor zero position correction amount and the corrected rotor zero position, and updates the rotor zero position in the memory, thereby simplifying the debugging steps of the three-phase permanent magnet motor, and after the rotor zero position is accurately positioned, the rotor will not rotate again when the three-phase permanent magnet motor is restarted, thereby improving its starting speed, improving the production debugging efficiency, and having good adaptability and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic flow chart of a method for determining a rotor zero position of a three-phase permanent magnet motor based on a D-axis vector according to an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the rotor zero position correction amount according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] The embodiment of the present invention provides a method for determining the zero position of a three-phase permanent magnet motor rotor based on a D-axis vector, such as Figure 1 As shown, the method includes:

[0030] S1. Obtain the rotor zero position stored in the memory and read the current position of the rotor for the first time.

[0031] Specifically, when the three-phase permanent magnet motor is started for the kth time, the rotor zero position x0(k) stored in the flash memory is read; and the current position x1 of the rotor is read for the first time through the high-precision position sensor.

[0032] S2. Output a D-axis voltage vector pointing to the current rotor position read for the first time according to the rotor zero position and the current rotor position read for the first time, so that the rotor is fixed at the current rotor position read for the first time.

[0033] Specifically, the D-axis voltage vector includes a D-axis voltage direction and a D-axis voltage modulus, wherein the D-axis voltage direction is calculated by the rotor zero position and the current rotor position read for the first time; and the D-axis voltage modulus is obtained by setting.

[0034] In a preferred embodiment of the present invention, the D-axis voltage modulus is set to The Q-axis voltage is set to U q =0, and output the D-axis voltage vector in combination with the calculated D-axis voltage direction.

[0035] S3, reading the current position of the rotor at a certain frequency interval, and obtaining the angular velocity by differentiating the current position of the rotor. When the angular velocity is less than a preset value, reading the current position of the rotor for the second time.

[0036] Specifically, after the D-axis voltage vector is output, a vertical force can be obtained to fix the rotating rotor, so that the rotor gradually stops rotating and the angular velocity slowly approaches 0. When the angular velocity is less than the preset value, the rotor is considered to have stopped rotating. At this time, the current position x2 of the rotor is read for the second time.

[0037] S4. Obtain a rotor zero position correction amount according to the rotor current position read for the second time and the rotor current position read for the first time, obtain a corrected rotor zero position in combination with the rotor zero position in the memory, and store the corrected rotor zero position in the memory.

[0038] Specifically, the rotor zero position correction is obtained by subtracting the current rotor position read for the second time from the current rotor position read for the first time, that is, x2-x1, that is, Figure 2 θ in , thus obtaining the corrected rotor zero position parameter:

[0039] x0(k+1)=x0(k)+x2-x1

[0040] The new rotor zero position parameter x0(k+1) is written into the Flash memory, and after the current startup, this parameter is used as the basis for control; when the three-phase permanent magnet motor is restarted once, the rotor zero position obtained is accurate, so when it is restarted again, the rotor zero position vector is output and the rotor no longer rotates.

[0041] In addition, an embodiment of the present invention provides a three-phase permanent magnet motor rotor zero position determination system based on a D-axis vector, which is used in the three-phase permanent magnet motor rotor zero position determination method based on a D-axis vector described in an embodiment of the present invention, and the system includes:

[0042] A reading module, used to obtain the rotor zero position stored in the memory and read the current position of the rotor for the first time;

[0043] A vector control module is used to output a D-axis voltage vector pointing to the current position of the rotor read for the first time according to the rotor zero position and the current position of the rotor read for the first time, so that the rotor is fixed at the current position of the rotor read for the first time;

[0044] A judgment module is used to read the current position of the rotor at a certain frequency interval, and to obtain the angular velocity by differentiating the current position of the rotor. When the angular velocity is less than a preset value, the current position of the rotor is read for a second time.

[0045] The correction module is used to obtain a rotor zero position correction value according to the rotor current position read for the second time and the rotor current position read for the first time, obtain a corrected rotor zero position in combination with the rotor zero position in the memory, and store the corrected rotor zero position in the memory.

[0046] Among them, the vector control module is specifically used to calculate the D-axis voltage direction according to the rotor zero position and the current rotor position read for the first time, and set the D-axis voltage modulus, and output the D-axis voltage vector pointing to the current rotor position read for the first time in combination with the D-axis voltage direction and the D-axis voltage modulus, so that the rotor is fixed at the current rotor position read for the first time; the correction module is specifically used to subtract the current rotor position read for the second time from the current rotor position read for the first time to obtain the rotor zero position correction amount, and then add the rotor zero position in the memory to the rotor zero position correction amount to obtain the corrected rotor zero position, and store the corrected rotor zero position in the memory.

[0047] The present invention outputs a D-axis voltage vector according to the rotor zero position stored in a memory in the three-phase permanent magnet motor to fix the rotor, reads the rotor position when the rotor angular velocity is less than a certain preset value, thereby obtaining the rotor zero position correction amount and the corrected rotor zero position, and updates the rotor zero position in the memory, thereby simplifying the debugging steps of the three-phase permanent magnet motor, and after the rotor zero position is accurately positioned, the rotor will not rotate again when the three-phase permanent magnet motor is restarted, thereby improving its starting speed, improving the production debugging efficiency, and having good adaptability and reliability.

[0048] At the same time, an embodiment of the present invention further provides a three-phase permanent magnet motor, which uses the three-phase permanent magnet motor rotor zero position determination method based on the D-axis vector described above to perform zero position positioning of the three-phase permanent magnet motor rotor.

[0049] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, and two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0050] The order of execution of each step in the above embodiment does not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0051] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A method for determining the zero position of a three-phase permanent magnet motor rotor based on a D-axis vector, characterized in that: The method comprises: Get the rotor zero position stored in the memory and read the current position of the rotor for the first time; Outputting a D-axis voltage vector pointing to the current position of the rotor read for the first time according to the rotor zero position and the current position of the rotor read for the first time, so that the rotor is fixed at the current position of the rotor read for the first time; The current position of the rotor is read at a certain frequency interval, and the angular velocity is obtained by differentiating the current position of the rotor. When the angular velocity is less than the preset value, the current position of the rotor is read for the second time. The rotor zero position correction amount is obtained according to the rotor current position read for the second time and the rotor current position read for the first time, and the corrected rotor zero position is obtained in combination with the rotor zero position in the memory, and the corrected rotor zero position is stored in the memory.

2. The method for determining the rotor zero position of a three-phase permanent magnet motor based on the D-axis vector according to claim 1, characterized in that: The D-axis voltage vector includes a D-axis voltage direction and a D-axis voltage modulus.

3. The method for determining the rotor zero position of a three-phase permanent magnet motor based on the D-axis vector according to claim 2 is characterized in that: The D-axis voltage direction is calculated from the rotor zero position and the current rotor position read for the first time; the D-axis voltage modulus is obtained by setting.

4. The method for determining the rotor zero position of a three-phase permanent magnet motor based on the D-axis vector according to claim 1, characterized in that: The rotor zero position correction is obtained by subtracting the rotor current position read for the second time from the rotor current position read for the first time.

5. The method for determining the rotor zero position of a three-phase permanent magnet motor based on the D-axis vector according to claim 1, characterized in that: The corrected rotor zero position is obtained by adding the rotor zero position correction amount to the rotor zero position in the memory.

6. The method for determining the rotor zero position of a three-phase permanent magnet motor based on the D-axis vector according to claim 1, characterized in that: The current position of the rotor is read by a high-precision position sensor.

7. A three-phase permanent magnet motor rotor zero position determination system based on D-axis vector, characterized in that: The system comprises: A reading module, used to obtain the rotor zero position stored in the memory and read the current position of the rotor for the first time; A vector control module is used to output a D-axis voltage vector pointing to the current position of the rotor read for the first time according to the rotor zero position and the current position of the rotor read for the first time, so that the rotor is fixed at the current position of the rotor read for the first time; A judgment module is used to read the current position of the rotor at a certain frequency interval, and to obtain the angular velocity by differentiating the current position of the rotor. When the angular velocity is less than a preset value, the current position of the rotor is read for a second time. The correction module is used to obtain a rotor zero position correction value according to the rotor current position read for the second time and the rotor current position read for the first time, obtain a corrected rotor zero position in combination with the rotor zero position in the memory, and store the corrected rotor zero position in the memory.

8. The three-phase permanent magnet motor rotor zero position determination system based on D-axis vector according to claim 7 is characterized in that: The vector control module is specifically used to calculate the D-axis voltage direction based on the rotor zero position and the current rotor position read for the first time, and to set the D-axis voltage modulus. In combination with the D-axis voltage direction and the D-axis voltage modulus, the D-axis voltage vector pointing to the current rotor position read for the first time is output, so that the rotor is fixed at the current rotor position read for the first time.

9. The three-phase permanent magnet motor rotor zero position determination system based on D-axis vector according to claim 7, characterized in that: The correction module is specifically used to subtract the rotor current position read for the second time from the rotor current position read for the first time to obtain a rotor zero position correction value, then add the rotor zero position in the memory to the rotor zero position correction value to obtain a corrected rotor zero position, and store the corrected rotor zero position in the memory.

10. A three-phase permanent magnet motor, characterized in that: The method for determining the zero position of a three-phase permanent magnet motor rotor based on a D-axis vector as described in any one of claims 1 to 6 is used to perform zero position positioning of the three-phase permanent magnet motor rotor.

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