阅读说明：本技术 一种永磁同步电机转子电角度的测试方法及系统 (Method and system for testing electric angle of rotor of permanent magnet synchronous motor ) 是由 潘炜 张振宁 纪秉男 杨开胜 焦福秦 刘辉 于 2018-07-18 设计创作，主要内容包括：本发明涉及一种永磁同步电机转子电角度的测试方法及系统,该测试方法包括：给电机三相绕组中的第一相和第二相绕组通大小相等且极性相反的设定直流电流,使电机的转子锁定在另外一相绕组的设定角度上,顺时针和/或逆时针转动电机转轴；测量对应顺时针和/或逆时针转动后的电机转子电角度,并对各不同顺时针转动角度的电机转轴所对应的电机转子电角度测量值和/或各不同逆时针转动角度的电机转轴所对应的电机转子电角度测量值求平均值,从而得到电机正向转子电角度和/或电机负向转子电角度。本发明通过测量转子多点的电角度值并取平均,并通过平均值来评估电机转子电角度,降低了由于转子机械角度不一致的误差,提高了测量精度。(The invention relates to a method and a system for testing the electric angle of a permanent magnet synchronous motor rotor, wherein the method comprises the following steps: the method comprises the steps that set direct current with the same magnitude and opposite polarity is conducted to a first phase winding and a second phase winding in three-phase windings of the motor, so that a rotor of the motor is locked on a set angle of the other phase winding, and a rotating shaft of the motor is rotated clockwise and/or anticlockwise; and measuring the electrical angle of the motor rotor after corresponding clockwise and/or counterclockwise rotation, and averaging the electrical angle measurement values of the motor rotor corresponding to the motor rotating shafts with different clockwise rotation angles and/or the electrical angle measurement values of the motor rotor corresponding to the motor rotating shafts with different counterclockwise rotation angles, so as to obtain the electrical angle of the positive rotor of the motor and/or the electrical angle of the negative rotor of the motor. The invention measures and averages the electric angle values of the rotor at multiple points, and evaluates the electric angle of the motor rotor through the average value, thereby reducing the error caused by the inconsistency of the mechanical angle of the rotor and improving the measurement precision.)

1. A method for testing the electric angle of a permanent magnet synchronous motor rotor is characterized by comprising the following steps:

the method comprises the steps that set direct current with the same magnitude and opposite polarity is conducted to a first phase winding and a second phase winding in three-phase windings of the motor, so that a rotor of the motor is locked on a set angle of the other phase winding, and a rotating shaft of the motor is rotated clockwise and/or anticlockwise;

and measuring the electrical angle of the motor rotor after corresponding clockwise and/or counterclockwise rotation, and averaging the electrical angle measurement values of the motor rotor corresponding to the motor rotating shafts with different clockwise rotation angles and/or the electrical angle measurement values of the motor rotor corresponding to the motor rotating shafts with different counterclockwise rotation angles, so as to obtain the electrical angle of the positive rotor of the motor and/or the electrical angle of the negative rotor of the motor.

2. The method for testing the rotor electrical angle of the permanent magnet synchronous motor according to claim 1, wherein the rotating shaft of the motor is rotated clockwise and/or counterclockwise according to all electrical cycles in a mechanical angle of 360 degrees, and the electrical angles of the rotor of the motor after clockwise and/or counterclockwise rotation corresponding to all electrical cycles are averaged, wherein one electrical cycle in the mechanical angle of 360 degrees is 60 °/k ± 5 °, and k is the ratio of the pole pair number and the pole pair number of the resolver of the motor.

3. The method for testing the rotor electrical angle of the permanent magnet synchronous motor according to claim 1 or 2, wherein the set direct current is 1/3-1/2 of the rated current of the motor.

4. The method for testing the rotor electrical angle of the permanent magnet synchronous motor according to claim 1 or 2, further comprising supplying set direct current with equal magnitude and opposite polarity to the first phase winding and the third phase winding and/or the second phase winding and the third phase winding in the three-phase windings of the motor, measuring the electrical angle of the motor rotor after corresponding clockwise and/or counterclockwise rotation, and averaging the measured values of the motor rotor electrical angles corresponding to the motor rotating shafts with all different clockwise rotation angles and/or the measured values of the motor rotor electrical angles corresponding to the motor rotating shafts with all different counterclockwise rotation angles, thereby obtaining the positive rotor electrical angle and/or the negative rotor electrical angle of the motor.

5. A system for testing the rotor electrical angle of a permanent magnet synchronous motor comprises a direct current power supply for supplying power to a motor to be tested and a motor rotor electrical angle measuring device for coaxially connecting the rotor of the motor to be tested, and is characterized in that the direct current power supply is used for supplying set direct current with equal magnitude and opposite polarity to a first phase winding and a second phase winding in a three-phase winding of the motor, so that the rotor of the motor is locked at a set angle of the other phase winding; the motor rotor electric angle measuring device is used for measuring the corresponding clockwise and/or counterclockwise rotated motor rotor electric angle after clockwise and/or counterclockwise rotating the motor rotating shaft; and averaging the measured values of the electric angles of the motor rotors corresponding to the motor rotating shafts with different clockwise rotation angles and/or the measured values of the electric angles of the motor rotors corresponding to the motor rotating shafts with different counterclockwise rotation angles, so as to obtain the electric angle of the positive rotor of the motor and/or the electric angle of the negative rotor of the motor.

6. The system for testing the rotor electrical angle of the permanent magnet synchronous motor according to claim 5, wherein the rotating shaft of the motor is rotated clockwise and/or counterclockwise according to all electrical cycles within a mechanical angle of 360 degrees, and the electrical angles of the rotor of the motor after clockwise and/or counterclockwise rotation corresponding to all electrical cycles are averaged, wherein one electrical cycle within the mechanical angle of 360 degrees is 60 °/k ± 5 °, and k is the ratio of the pole pair number and the pole pair number of the resolver of the motor.

7. The system for testing the rotor electrical angle of the permanent magnet synchronous motor according to claim 5 or 6, wherein the set direct current is 1/3-1/2 of the rated current of the motor.

8. The system for testing the rotor electrical angle of the permanent magnet synchronous motor according to claim 5 or 6, wherein the direct current power supply is further configured to supply set direct currents with equal magnitude and opposite polarity to the first phase winding and the third phase winding and/or the second phase winding and the third phase winding in the three-phase windings of the motor, the device for measuring the rotor electrical angle of the motor is further configured to measure the rotor electrical angle of the motor after corresponding clockwise and/or counterclockwise rotation, and average the measured values of the rotor electrical angle of the motor corresponding to all the motor rotating shafts with different clockwise rotation angles and/or the measured values of the rotor electrical angle of the motor corresponding to all the motor rotating shafts with different counterclockwise rotation angles, so as to obtain the rotor electrical angle of the motor in the positive direction and/or the rotor electrical angle of the motor in the negative direction.

Technical Field

The invention relates to a method and a system for testing the electric angle of a rotor of a permanent magnet synchronous motor, and belongs to the technical field of permanent magnet synchronous motor control.

Background

With the development of lightweight automobile parts, the requirements on the efficiency and power density of a permanent magnet synchronous motor (hereinafter referred to as a motor) are higher and higher. Under the condition that the structural type, the size and the material selection of the motor are not changed, the testing precision of the position of the motor rotor is improved, and the measured value of the electrical angle of the rotor is directly fixed in a control program, so that the error caused by self-learning of the electrical angle by a controller can be avoided, the output performance of the motor is improved, and the riding comfort of a vehicle is improved; on the other hand, the controller identification of being convenient for reduces the rework in production, improves installation efficiency.

The principle of testing the electrical angle of the rotor of the existing motor is as follows: the angle display is connected with a motor rotary transformer through a socket, and the electrical angle of a motor rotor is measured through the rotary transformer coaxially connected with the motor. As shown in fig. 1, the motor M1 is supplied with a positive U-phase direct current and a large I (1/3-1/2 of rated current), the V-phase and the W-phase direct currents and a large 0.5 × I, the rotor of the motor is locked at the zero position of the U-phase, and the electrical angle value of a rotary transformer M2 coaxially connected with the motor is read through an angular position display, so that the electrical angle of the rotor of the motor is detected.

The method can lock the motor rotor at the zero-degree position of the U phase theoretically, but is actually limited by the manufacturing level of the motor, the U phase, the V phase and the W phase of the motor are not completely symmetrical, and even if the influence of three-phase symmetry is not considered, the currents of the V phase and the W phase are not equal (not equal to-0.5I) due to certain deviation of the V phase and the W phase on resistance inductance parameters, so that the position of rotor locking has certain deviation from a theoretical zero point, and the accuracy of the electric angle test of the motor rotor is influenced. On the other hand, due to errors in the manufacturing process of the motor, each electrical cycle is not strictly 360 °/(2P, where P is the number of pole pairs of the motor) within a 360 ° mechanical angle of the rotor of the motor, so that the zero point of each electrical cycle is not always the same, and there is a great risk in evaluating the whole motor by measuring the electrical angle in one electrical cycle.

Disclosure of Invention

The invention aims to provide a method and a system for testing the electric angle of a permanent magnet synchronous motor rotor, which are used for solving the problem of inaccurate measurement of the electric angle of the motor rotor.

In order to solve the technical problem, the invention provides a method for testing the electric angle of a permanent magnet synchronous motor rotor, which comprises the following steps:

the method comprises the steps that set direct current with the same magnitude and opposite polarity is conducted to a first phase winding and a second phase winding in three-phase windings of the motor, so that a rotor of the motor is locked on a set angle of the other phase winding, and a rotating shaft of the motor is rotated clockwise and/or anticlockwise;

and measuring the electrical angle of the motor rotor after corresponding clockwise and/or counterclockwise rotation, and averaging the electrical angle measurement values of the motor rotor corresponding to the motor rotating shafts with different clockwise rotation angles and/or the electrical angle measurement values of the motor rotor corresponding to the motor rotating shafts with different counterclockwise rotation angles, so as to obtain the electrical angle of the positive rotor of the motor and/or the electrical angle of the negative rotor of the motor.

The invention has the beneficial effects that: the electric angle value of the rotor at multiple points is measured and averaged, and the electric angle of the motor rotor is evaluated through the average value, so that the error caused by the inconsistency of the mechanical angle of the rotor is reduced, and the measurement precision is improved.

Further, the motor rotating shaft is rotated clockwise and/or anticlockwise according to all electrical cycles in the mechanical angle of 360 degrees, the electrical angles of the motor rotor after the clockwise and/or anticlockwise rotation corresponding to all the electrical cycles are averaged, wherein one electrical cycle in the mechanical angle of 360 degrees is 60 degrees/k +/-5 degrees, and k is the ratio of the pole pair number and the rotational pole pair number of the motor.

The measurement precision is further improved by measuring the electric angles of the motor rotor in all electric periods within the mechanical angle of 360 degrees and averaging.

Furthermore, the set direct current is 1/3-1/2 of the rated current of the motor.

And further, the method comprises the steps of supplying set direct current with equal magnitude and opposite polarity to a first phase winding and a third phase winding and/or a second phase winding and a third phase winding in three-phase windings of the motor, measuring the electric angles of the motor rotor after clockwise and/or anticlockwise rotation, and averaging the measured values of the electric angles of the motor rotor corresponding to all the motor rotating shafts with different clockwise rotation angles and/or the measured values of the electric angles of the motor rotor corresponding to all the motor rotating shafts with different anticlockwise rotation angles, so as to obtain the positive electric angle of the rotor of the motor and/or the negative electric angle of the rotor of the motor.

By means of charging the two windings of different motors, test errors caused by unbalanced current in the three-phase winding are eliminated, and measuring accuracy is improved.

The invention also provides a system for testing the electric angle of the rotor of the permanent magnet synchronous motor, which comprises a direct-current power supply for supplying power to the motor to be tested and a motor rotor electric angle measuring device for coaxially connecting the rotor of the motor to be tested, wherein the direct-current power supply is used for supplying set direct currents with equal magnitude and opposite polarity to a first phase winding and a second phase winding in a three-phase winding of the motor, so that the rotor of the motor is locked at the set angle of the other phase winding; the motor rotor electric angle measuring device is used for measuring the corresponding clockwise and/or counterclockwise rotated motor rotor electric angle after clockwise and/or counterclockwise rotating the motor rotating shaft; and averaging the measured values of the electric angles of the motor rotors corresponding to the motor rotating shafts with different clockwise rotation angles and/or the measured values of the electric angles of the motor rotors corresponding to the motor rotating shafts with different counterclockwise rotation angles, so as to obtain the electric angle of the positive rotor of the motor and/or the electric angle of the negative rotor of the motor.

Further, the motor rotating shaft is rotated clockwise and/or anticlockwise according to all electrical cycles in the mechanical angle of 360 degrees, the electrical angles of the motor rotor after the clockwise and/or anticlockwise rotation corresponding to all the electrical cycles are averaged, wherein one electrical cycle in the mechanical angle of 360 degrees is 60 degrees/k +/-5 degrees, and k is the ratio of the pole pair number and the rotational pole pair number of the motor.

Furthermore, the set direct current is 1/3-1/2 of the rated current of the motor.

Further, the dc power supply is further configured to supply set dc currents having the same magnitude and opposite polarities to the first phase and the third phase windings and/or the second phase and the third phase windings in the three-phase windings of the motor, and the motor rotor electrical angle measuring device is further configured to measure electrical angles of the motor rotor after corresponding clockwise and/or counterclockwise rotation, and average values of electrical angle measurement values of the motor rotor corresponding to all motor rotating shafts with different clockwise rotation angles and/or electrical angle measurement values of the motor rotor corresponding to all motor rotating shafts with different counterclockwise rotation angles, so as to obtain an electrical angle of the positive rotor of the motor and/or an electrical angle of the negative rotor of the motor.

Drawings

FIG. 1 is a schematic diagram of an electrical angle test of a rotor of a prior art motor;

fig. 2 is a schematic structural diagram of a system for testing the electrical angle of the rotor of the permanent magnet synchronous motor.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

The invention provides a system for testing the electric angle of a permanent magnet synchronous motor rotor, which comprises a direct-current power supply for supplying power to a permanent magnet synchronous motor M3 to be tested and a motor rotor electric angle measuring device for coaxially connecting the motor rotor to be tested.

As shown in fig. 2, in the present embodiment, the device for measuring the electrical angle of the motor rotor is a motor resolver M4, and the motor resolver M4 is coaxially connected to the to-be-measured permanent magnet synchronous motor M3 and is used for measuring the electrical angle of the motor rotor. The motor rotary transformer is connected with an angular position display through a suspension transformer socket and used for sending the measured electric angle of the motor rotor to the angular position display for displaying. Of course, as another embodiment, when the electric angle measurement of the motor rotor is possible, the motor resolver may be replaced with another measuring device.

When the rotor electric angle of a certain permanent magnet synchronous motor needs to be measured, the permanent magnet synchronous motor to be measured can be used for a vehicle or can be used in other occasions, the permanent magnet synchronous motor to be measured is connected with a direct current power supply and a motor rotor electric angle measuring device in the permanent magnet synchronous motor rotor electric angle testing system, and therefore the permanent magnet synchronous motor rotor electric angle testing method is achieved, and the method specifically comprises the following steps:

(1) and a first phase winding and a second phase winding in the three-phase winding of the motor are supplied with set direct currents with equal magnitude and opposite polarities, so that the rotor of the motor is locked at a set angle of the other phase winding, and the rotating shaft of the motor is rotated clockwise and anticlockwise.

The first phase winding and the second phase winding in the three-phase windings of the motor are any two-phase windings in the three-phase windings of the motor. For example, when the first phase winding is a U-phase and the second phase winding is a V-phase, the other phase winding is a W-phase; when the first phase winding is a V phase and the second phase winding is a W phase, the other phase winding is a U phase; when the first phase winding is W phase, and the second phase winding is U phase, the other phase winding is V phase.

(2) And measuring the electric angles of the motor rotors corresponding to the clockwise rotation and the anticlockwise rotation, and averaging the measured values of the electric angles of the motor rotors corresponding to the motor rotating shafts with different clockwise rotation angles and the measured values of the electric angles of the motor rotors corresponding to the motor rotating shafts with different anticlockwise rotation angles, so as to obtain the electric angles of the positive rotor of the motor and the negative rotor of the motor.

In step (2), the electrical angle value of the rotary transformer coaxially connected to the motor is read by the angular position display, and the rotor electrical angle of the motor is detected. By rotating the motor rotating shaft clockwise and anticlockwise for multiple times, the clockwise rotation times and the anticlockwise rotation times are positive integers not less than 2, the electric angle values of the rotor multiple points are measured and averaged, the electric angle of the motor rotor is evaluated through the average value, the error caused by the inconsistency of the mechanical angle of the rotor is reduced, and the measurement precision is improved.

As a further improvement, in order to reduce the error caused by the inconsistency of the mechanical angle of each electrical cycle, the electrical angle of the rotor of the motor is evaluated through an average value by measuring and averaging electrical angle values of a plurality of points of the rotor in all electrical cycles of the mechanical angle of 360 degrees. Rotating a motor rotating shaft clockwise and anticlockwise according to all electric periods within a mechanical angle of 360 degrees, and averaging the electric angles of the motor rotor which rotates clockwise correspondingly to all the electric periods so as to obtain the average value of the electric angles of the forward rotor of the motor; and averaging the electric angles of the motor rotor after the counterclockwise rotation corresponding to all the electric periods so as to obtain the negative direction rotor electric angle average value of the motor.

Specifically, one electrical cycle in a 360-degree mechanical angle is 60 degrees/k +/-5 degrees, and k is the ratio of the pole pair number and the rotary change pole pair number of the motor. The method comprises the steps of adopting a mode of electrifying two-phase windings of the motor, taking a first-phase winding as a V-phase winding and a second-phase winding as a W-phase winding as an example, providing a positive set direct current for the V-phase of the motor, providing a magnitude of I, providing a negative set direct current for the W-phase of the motor, enabling a rotor of the motor to be locked at a set angle position of a U-phase, rotating a rotating shaft of the motor clockwise for one electric period, and reading a rotary electrical angle value theta of a rotary transformer coaxially connected with the motor through an angle position display_VW1+. Then, a type of electrifying two-phase windings of the motor is adopted, positive set direct current is communicated with a V phase of the motor, the magnitude is I, negative set direct current is communicated with a W phase, the magnitude is I, a rotor of the motor is locked on a set angle position of a U phase, a rotating shaft of the motor is rotated anticlockwise for one electric period, and a rotary electrical angle value theta coaxially connected with the motor is read through an angle position display_VW1-. In the present embodiment, the DC current is 1/3-1/2 of the rated current of the motor, and the set angle is 90 °.

By the method, the rotating shaft of the motor is continuously rotated clockwise and anticlockwise, so that the forward electric angle value theta of the rotor in all electric periods within 360-degree mechanical angle is obtained_VW1+、θ_VW2+、θ_VW3+、……、θ_VWP+Negative rotor angle values θ for all electrical cycles_VW1-、θ_VW2-、θ_VW3-、……、θ_VWP-. For all rotor positive direction electric angle values theta_VW1+、θ_VW2+、θ_VW3+、……、θ_VWP+Averaging to obtain the forward rotor electricity of the motorAn angle; for all negative electric angle values theta of the rotor_VW1-、θ_VW2-、θ_VW3-、……、θ_VWP-And averaging to obtain the negative rotor electric angle of the motor.

In order to eliminate the test error caused by the current imbalance in the three-phase winding and improve the measurement precision, the positive direction set direct current with the magnitude of I is communicated with the W of the motor, the negative direction set direct current with the magnitude of I is communicated with the U of the motor, and the positive direction electric angle value theta of the rotor in all electric periods within the mechanical angle of 360 degrees is tested by the same method_WU1+、θ_WU2+、θ_WU3+、……、θ_WUP+Negative rotor angle values θ for all electrical cycles_WU1-、θ_WU2-、θ_WU3-、……、θ_WUP-. Testing the positive electric angle value theta of the rotor in all electric periods within 360-degree mechanical angle by providing a positive set direct current I for the U-phase of the motor and a negative set direct current I for the V-phase of the motor_UV1+、θ_UV2+、θ_UV3+、……、θ_UVP+Negative rotor angle values θ for all electrical cycles_UV1-、θ_UV2-、θ_UV3-、……、θ_UVP-. Similarly, the direct current is set to 1/3-1/2 of the rated current of the motor, and the set angle is 90 degrees.

At this time, the average value theta of all the forward rotor electrical angles of the motor₊Comprises the following steps:

θ₊＝(θ_VW1++θ_VW2++θ_VW3++…+θ_VWP++θ_WU1++θ_WU2++θ_WU3++…+θ_WUP+

+θ_UV1++θ_UV2++θ_UV3++…+θ_UVP+)/3P

average value theta of all negative rotor electrical angles of the motor_-Comprises the following steps:

θ_-＝(θ_VW1-+θ_VW2-+θ_VW3-+…+θ_VWP-+θ_WU1-+θ_WU2-+θ_WU3-+…+θ_WUP-

+θ_UV1-+θ_UV2-+θ_UV3-+…+θ_UVP-)/3P

finally, averaging the measured values of the electrical angles of the motor rotor corresponding to the motor rotating shafts with different clockwise rotation angles, namely averaging the electrical angles theta of the forward rotor of the motor₊Measuring the electric angle of the positive rotor of the motor, and averaging the measured values of the electric angles of the motor rotors corresponding to the motor rotating shafts with different counterclockwise rotation angles, namely averaging the electric angles of the negative rotor of the motor_{_}To measure the negative rotor electrical angle of the motor. Through the mode of electrifying the three groups of different two-phase windings, set direct currents with equal magnitude and opposite polarity are supplied to any two-phase winding of the motor, the current imbalance in the windings is avoided, and the measurement precision of the rotor electric angle of the motor is improved.

It should be noted that, any two different sets of two-phase windings in the three-phase windings may also be energized, for example, a V-phase and a W-phase of the motor are communicated with dc currents having the same magnitude and opposite polarity, a W-phase and a U-phase of the motor are communicated with dc currents having the same magnitude and opposite polarity, so as to obtain positive electrical angle values and negative electrical angle values of the rotor corresponding to all electrical periods in two sets of 360 ° mechanical angles, and an average value of the two positive electrical angle values and an average value of the two negative electrical angle values are obtained as a final positive electrical angle of the rotor of the motor and a final negative electrical angle of the rotor of the motor.

In addition, when only the positive rotor electrical angle or the negative rotor electrical angle of the motor needs to be measured, after the two-phase winding of the motor is electrified, only the rotating shaft of the motor needs to be rotated clockwise or anticlockwise, and then the corresponding measured motor rotor electrical angle value is obtained and averaged to be used as the final positive rotor electrical angle or the negative rotor electrical angle of the motor.

The method and the system for testing the rotor electric angle of the permanent magnet synchronous motor can be applied to various driving parts with the permanent magnet synchronous motor, such as commercial vehicles, passenger vehicles, engineering machinery and the like, and avoid current imbalance in windings by adopting a form of electrifying two-phase windings; the electric angles of the rotor in all electric angle periods in a 360-degree mechanical angle are measured, the average value is obtained, the electric angle of the rotor of the motor is evaluated through the average value, the test error caused by the fact that the current in the three-phase winding is unbalanced and the electric period is not strict 360/(2P) is reduced, and the test accuracy is improved.