阅读说明：本技术 一种永磁同步电机零位标定方法及装置 (Method and device for calibrating zero position of permanent magnet synchronous motor ) 是由 毕亮亮 于 2020-12-18 设计创作，主要内容包括：本发明公开了一种永磁同步电机零位标定方法,包括如下步骤：S1、控制开关到达初始状态,获取此时转子的实际角度θ-1；S2、以θ-偏为转子的偏转目标值,控制开关到达偏转状态,获取此时转子的实际角度θ-2；其中θ-偏＝60°*m/n,m＝1,2,3,n为极对数；S3、根据如下公式计算转子的零位角度θ-0：其中θ-e＝|θ-1-θ-2|。由于采用了上述技术方案,与现有技术相比,本发明只需要改变开关状态就可以直接进行对电机零位的标定,标定过程简单直接。(The invention discloses a zero calibration method for a permanent magnet synchronous motor, which comprises the following steps: s1, controlling the switch to reach the initial state, and acquiring the actual angle theta of the rotor at the moment 1 (ii) a S2 at theta Deflection Controlling the switch to reach a deflection state for a deflection target value of the rotor, and acquiring an actual angle theta of the rotor at the moment 2 (ii) a Wherein theta is Deflection 60 degrees m/n, m 1, 2, 3, n is the pole pair number; s3, calculating the zero position angle theta of the rotor according to the following formula 0 ： Wherein theta is e ＝|θ 1 ‑θ 2 L. Due to the adoption of the technical scheme, compared with the prior art, the zero position of the motor can be directly calibrated only by changing the switch state, and the calibration process is simple and direct.)

1. A zero calibration method for a permanent magnet synchronous motor is characterized by comprising the following steps:

s1, controlling the switch to reach the initial state, and acquiring the actual angle theta of the rotor at the moment₁；

S2 at theta_DeflectionControlling the switch to reach a deflection state for a deflection target value of the rotor, and acquiring an actual angle theta of the rotor at the moment₂(ii) a Wherein theta is_Deflection60 degrees m/n, m 1, 2, 3, n is the pole pair number;

s3, calculating the zero position angle theta of the rotor according to the following formula₀：Wherein theta is_e＝|θ₁-θ₂|。

2. The method for calibrating the zero position of the permanent magnet synchronous motor according to claim 1, wherein the step of step S3 is further followed by the step of:

s4, giving a rotation command to rotate the rotor for one circle;

and S5, acquiring the actual rotating speed of the rotor, and if the actual rotating speed of the rotor is not equal to the given rotating speed of the rotor, returning to the step S1 until the actual rotating speed of the rotor is equal to the given rotating speed of the rotor.

3. The method for calibrating the zero position of the permanent magnet synchronous motor according to claim 2, characterized in that: the actual rotation speed of the rotor is obtained according to the following formula:

actual rotational speedWhere θ is the instantaneous mechanical angle of the rotor as defined by the angle sensor, t is time, dt represents a very small time variable, and d θ represents the mechanical angle of rotation of the motor rotor at the time of dt.

4. The method for calibrating the zero position of the permanent magnet synchronous motor according to claim 1 or 2, characterized in that: and m is 1.

5. The utility model provides a PMSM zero position calibration device which characterized in that: the device comprises a switch, a motor control system, a calculation unit and an angle sensor;

the motor control system is connected with the switch and used for sequentially sending an initial instruction and a deflection instruction to the switch so as to sequentially enable the rotor to be in an initial state and a deflection state; the target deflection value of the rotor from the initial state to the deflection state is theta_DeflectionWherein theta_Deflection60 degrees m/n, m 1, 2, 3, n is the pole pair number;

the angle sensor is used for acquiring the actual angle theta when the rotor is in the initial state₁And the actual angle theta of the rotor in the deflected state₂And will be theta₁And theta₂The value of (a) is output to the calculation unit;

the calculation unit is used for acquiring the zero position angle theta of the rotor according to the following formula₀：Wherein theta is_e＝|θ₁-θ₂|。

6. The device for calibrating the zero position of the permanent magnet synchronous motor according to claim 5, is characterized in that:

the motor control system is also used for sending a rotation instruction to the switch after sending a deflection instruction so as to enable the rotor to rotate for one circle; the control device is also used for comparing the actual rotating speed of the rotor with the given rotating speed, and when the actual rotating speed of the rotor is not equal to the given rotating speed, the control device sends the initial command, the deflection command and the rotation command to the switch again in sequence until the actual rotating speed of the rotor is equal to the given rotating speed; the actual rotation speed of the rotor is obtained according to the following formula:where θ is the instantaneous mechanical angle of the rotor as defined by the angle sensor, t is time, dt represents a very small time variable, and d θ represents the mechanical angle of rotation of the motor rotor at the time of dt.

7. The permanent magnet synchronous motor zero calibration device according to claim 5 or 6, characterized in that: the angle sensor is an absolute angle encoder.

8. The permanent magnet synchronous motor zero calibration device according to claim 5 or 6, characterized in that: and m is 1.

Technical Field

The invention relates to the field of motor control, in particular to a method and a device for calibrating a zero position of a permanent magnet synchronous motor.

Background

Permanent Magnet Synchronous Motors (PMSM) have the advantages of small size, high power density and high electromechanical energy conversion efficiency, and are increasingly applied to the fields of industry, manufacturing industry, national defense and the like. However, because the rotor of the permanent magnet synchronous motor is made of a permanent magnet material, when armature current is added to the rotor, an induction electromagnetic field cannot be generated on the rotor, so that the permanent magnet synchronous motor does not have the self-starting capability, and therefore, the initial position of the rotor of the motor needs to be detected when the motor is normally started, namely, the zero position of the motor needs to be calibrated.

Chinese patent publication No. CN108418492A discloses a zero calibration method, a calibration device and a control system for a permanent magnet synchronous motor, which have the following disadvantages: the zero calibration method of the synchronous motor needs to determine the zero of the motor through the speed value and the speed change value of the motor, and the calibration method is quite complex.

Disclosure of Invention

In order to solve the problem that the existing zero calibration method of the permanent magnet synchronous motor in the background technology is very complex, the invention provides a zero calibration method of the permanent magnet synchronous motor, and the specific technical scheme is as follows.

A zero calibration method for a permanent magnet synchronous motor comprises the following steps:

s1, controlling the switch to reach the initial state, and acquiring the actual angle theta of the rotor at the moment₁；

S2 at theta_DeflectionControlling the switch to reach a deflection state for a deflection target value of the rotor, and acquiring an actual angle theta of the rotor at the moment₂(ii) a Wherein theta is_Deflection60 degrees m/n, m 1, 2, 3, n is the pole pair number;

s3, calculating the zero position angle theta of the rotor according to the following formula₀：Wherein theta is_e＝|θ₁-θ₂|。

By the method, the zero position of the motor can be directly calibrated only by changing the switch state, and the calibration process is simple and direct.

Preferably, the method further comprises the following step after S3:

s4, giving a rotation command to rotate the rotor for one circle;

and S5, acquiring the actual rotating speed of the rotor, and if the actual rotating speed of the rotor is not equal to the given rotating speed of the rotor, returning to the step S1 until the actual rotating speed of the rotor is equal to the given rotating speed of the rotor.

In order to verify the accuracy of the motor zero position, the motor zero position angle theta is adopted₀After the rotation is determined, the motor can rotate at a low speed for a circle, the motor is enabled after a rotation instruction is given, the position of a rotor does not change suddenly, and if the given rotating speed is equal to the actual rotating speed in the rotation process, the zero position of the motor is found accurately; if the motor is abnormal in rotation, the motor zero position angle theta is indicated₀The calibration method needs to be adopted to carry out calibration again and verify the zero precision of the motor again until the actual rotating speed of the rotor is equal to the given rotating speed of the rotor.

Preferably, the actual rotational speed of the rotor is obtained according to the following formula:

actual rotational speedWhere θ is the instantaneous mechanical angle of the rotor as defined by the angle sensor, t is time, dt represents a very small time variable, and d θ represents the mechanical angle of rotation of the motor rotor at the time of dt.

Preferably, m is 1. When m is 1, the stator magnetic field of the motor can only be converted into a state adjacent to the stator magnetic field, the rotor rotates to another adjacent stable state along with the change of the stator magnetic field, and the action of the switch is minimum, so that the on-off loss of the switch can be reduced to the minimum.

Based on the same inventive concept, the invention also provides a zero calibration device of the permanent magnet synchronous motor, which comprises a switch, a motor control system, a calculation unit and an angle sensor;

the motor control system is connected with the switch and used for sequentially sending an initial instruction and a deflection instruction to the switch so as to sequentially enable the rotor to be in an initial state and a deflection state; the target deflection value of the rotor from the initial state to the deflection state is theta_DeflectionWherein theta_Deflection60 degrees m/n, m 1, 2, 3, n is the pole pair number;

the angle sensor is used for acquiring the actual angle theta when the rotor is in the initial state₁And the actual angle theta of the rotor in the deflected state₂And will be theta₁And theta₂The value of (a) is output to the calculation unit;

the calculation unit is used for acquiring the zero position angle theta of the rotor according to the following formula₀： Wherein theta is_e＝|θ₁-θ₂|。

Through the structure, the zero position of the motor can be directly calibrated only by changing the switch state, and the calibration process is simple and direct.

Preferably, the motor control system is further configured to send a rotation command to the switch after sending the deflection command, so as to rotate the rotor for one revolution; the control device is also used for comparing the actual rotating speed of the rotor with the given rotating speed, and when the actual rotating speed of the rotor is not equal to the given rotating speed, the control device sends the initial command, the deflection command and the rotation command to the switch again in sequence until the actual rotating speed of the rotor is equal to the given rotating speed; the actual rotation speed of the rotor is obtained according to the following formula:where θ is the instantaneous mechanical angle of the rotor as defined by the angle sensor, t is time, dt represents a very small time variable, and d θ represents the mechanical angle of rotation of the motor rotor at the time of dt.

In order to verify the accuracy of the motor zero position, the motor zero position angle theta is adopted₀After the rotation is determined, the motor can rotate at a low speed for a circle, the motor is enabled after a rotation instruction is given, the position of a rotor does not change suddenly, and if the given rotating speed is equal to the actual rotating speed in the rotation process, the zero position of the motor is found accurately; if the motor is abnormal in rotation, the motor zero position angle theta is indicated₀The device needs to be adopted to calibrate again and verify the zero precision of the motor again until the actual rotating speed of the rotor is equal to the given rotating speed of the rotor.

Specifically, the angle sensor is an absolute angle sensor. More specifically, the absolute angle sensor comprises a grating or a rotary encoder.

Preferably, m is 1. When m is 1, the stator magnetic field of the motor can only be converted into a state adjacent to the stator magnetic field, the rotor rotates to another adjacent stable state along with the change of the stator magnetic field, and the action of the switch is minimum, so that the on-off loss of the switch can be reduced to the minimum.

Compared with the prior art, the zero calibration method has the advantages that the zero calibration of the motor can be directly carried out only by changing the switch state, and the calibration process is simple and direct.

Drawings

FIG. 1 is a schematic flow chart of a zero calibration method for a permanent magnet synchronous motor according to the present invention;

FIG. 2 is a schematic circuit connection diagram of the zero calibration device of the permanent magnet synchronous motor according to the present invention;

fig. 3 is a schematic diagram of a full-bridge topology of the switch according to embodiment 2 of the present invention;

FIG. 4 is a schematic view showing a state where a rotor is in an initial state in embodiment 2 of the present invention;

fig. 5 is a schematic view of a state in which the rotor is in a deflected state in embodiment 2 of the present invention.

Detailed Description

The present invention is described in further detail below with reference to the attached drawing figures.

Example 1

As shown in fig. 1, a method for calibrating a zero position of a permanent magnet synchronous motor includes the following steps:

s1, controlling the switch to reach the initial state, and acquiring the actual angle theta of the rotor at the moment₁；

S2 at theta_DeflectionControlling the switch to reach a deflection state for a deflection target value of the rotor, and acquiring an actual angle theta of the rotor at the moment₂(ii) a Wherein theta is_Deflection60 degrees m/n, m is 1, n is the pole pair number;

s3, calculating the zero position angle theta of the rotor according to the following formula₀：Wherein theta is_e＝|θ₁-θ₂|；

S4, giving a rotation command to rotate the rotor for one circle;

s5, acquiring the actual rotating speed of the rotor, and comparing the actual rotating speed of the rotor with the given rotating speed of the rotor; if the actual rotation speed of the rotor is not equal to the given rotation speed of the rotor, the step S1 is returned to until the actual rotation speed of the rotor is equal to the given rotation speed of the rotor. The actual rotation speed of the rotor is obtained according to the following formula: actual rotational speedWhere θ is the instantaneous mechanical angle of the rotor as defined by the angle sensor, t is time, dt represents a very small time variable, and d θ represents the mechanical angle of rotation of the motor rotor at the time of dt.

In this embodiment, the angle sensor is an absolute angle sensor, and more specifically, the absolute angle sensor includes a grating or a rotary encoder.

Example 2

As shown in fig. 2, a zero calibration device for a permanent magnet synchronous motor includes a switch, a motor control system, a computing unit and an angle sensor;

the motor control system is connected with the switch, and the switch is connected with the permanent magnet synchronous motor; the motor control system is used for sequentially sending an initial instruction and a deflection instruction to the switch so as to sequentially enable the rotor of the permanent magnet synchronous motor to be in an initial state and a deflection state; the target deflection value of the rotor from the initial state to the deflection state is theta_DeflectionWherein theta_Deflection60 ° × m/n, n being the number of pole pairs. In this embodiment, the angle sensor is an absolute angle sensor, and more specifically, the absolute angle sensor includes a grating or a rotary encoder. Specifically, m is 1 and n is 1.

Specifically, as shown in fig. 3, the switch includes a first switch tube 1, a second switch tube 2, a third switch tube 3, a fourth switch tube 4, a fifth switch tube 5 and a sixth switch tube 6, the switch tubes 1-6 form a bridge circuit and are connected to the permanent magnet synchronous motor, and this structure is a conventional structure for operating the permanent magnet synchronous motor, and the present invention does not make any improvement on this structure. When the switching tubes 1, 5 and 6 are switched on and the other switching tubes are switched off, the rotor is finally stabilized in an initial state, as shown in fig. 4; when the switching tubes 1, 5, 3 are turned on and the remaining switching tubes are turned off, the rotor will eventually settle in a deflected state, as shown in fig. 5. The method for realizing the deflection of the rotor by the specified angle through the conduction and the closing of the switching tube is also common knowledge in the field of permanent magnet synchronous motors, and the invention improves the method.

The motor control system sends an initial instruction to the switch and also sends a first angle measurement instruction to the angle sensor, and the angle sensor obtains an actual angle theta when the rotor is in an initial state after receiving the first angle measurement instruction₁；

The motor control system sends a deflection instruction to the switch and also sends a second angle measurement instruction to the angle sensor, and the angle sensor obtains an actual angle theta when the rotor is in a deflection state after receiving the second angle measurement instruction₂；

The angle sensor acquires theta₁And theta₂After a value of (d), and θ₁And theta₂The value of (a) is output to the calculation unit;

the calculation unit is used for acquiring the zero position angle theta of the rotor according to the following formula₀： Wherein theta is_e＝|θ₁-θ₂L, |; and obtaining the zero angle theta of the rotor₀Then, sending a verification signal to the motor control system;

the motor control system sends rotation to the switch after receiving the verification signalInstructing the rotor to rotate for one circle; and simultaneously sending a speed measurement instruction to the angle sensor, obtaining angle data theta of the rotor by the angle sensor after receiving the speed measurement instruction and sending the angle data to the calculation unit, and obtaining the actual rotating speed of the rotor by the calculation unit according to the following formulaThen sending the calculated actual rotating speed to the motor control unit; where θ is the instantaneous mechanical angle of the rotor as defined by the angle sensor, t is time, dt represents a very small time variable, and d θ represents the mechanical angle of rotation of the motor rotor at the time of dt.

The motor control system compares the actual rotating speed of the rotor with the given rotating speed, and when the actual rotating speed of the rotor is not equal to the given rotating speed, the motor control system sends an initial instruction, a deflection instruction and a rotation instruction to the switch in sequence until the actual rotating speed of the rotor is equal to the given rotating speed, and at the moment, the zero position angle theta of the rotor is output₀And completing the calibration of the zero position of the permanent magnet synchronous motor.

In this embodiment, the angle sensor is an absolute angle sensor, and more specifically, the absolute angle sensor includes a grating or a rotary encoder.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.