阅读说明：本技术 适用于无传感控制的电机 (Motor suitable for sensorless control ) 是由 孙鹏 于 2019-10-28 设计创作，主要内容包括：本发明提供了一种适用于无传感控制的电机,所述电机包括电机主体部和电机辅助部,所述电机主体部包括定子组件、转子组件以及电机轴；所述电机辅助部包括辅助绕组以及辅助永磁体组；所述转子组件和辅助永磁体组分别固定在所述电机轴的轴向的不同位置,且所述定子组件环绕所述转子组件设置,所述辅助绕组环绕所述辅助永磁体组设置。本发明实施例通过设置独立于电机主体部的辅助永磁体组和辅助绕组,可在电机主体部运行过程中产生辅助速度/位置信号,使无速度/位置传感控制在低速段更准确,更可靠,从而弥补无速度传感观测器在低速段无法满足应用需求的难点。(The invention provides a motor suitable for sensorless control, which comprises a motor main body part and a motor auxiliary part, wherein the motor main body part comprises a stator assembly, a rotor assembly and a motor shaft; the motor auxiliary part comprises an auxiliary winding and an auxiliary permanent magnet group; the rotor assembly and the auxiliary permanent magnet set are respectively fixed at different axial positions of the motor shaft, the stator assembly is arranged around the rotor assembly, and the auxiliary winding is arranged around the auxiliary permanent magnet set. According to the embodiment of the invention, the auxiliary permanent magnet group and the auxiliary winding which are independent from the main body part of the motor are arranged, so that an auxiliary speed/position signal can be generated in the running process of the main body part of the motor, the speed/position sensorless control is more accurate and more reliable in the low-speed section, and the difficulty that the speed sensorless observer cannot meet the application requirement in the low-speed section is overcome.)

1. A motor suitable for sensorless control is characterized by comprising a motor main body part and a motor auxiliary part, wherein the motor main body part comprises a stator assembly, a rotor assembly and a motor shaft; the motor auxiliary part comprises an auxiliary winding and an auxiliary permanent magnet group; the rotor assembly and the auxiliary permanent magnet set are respectively fixed at different axial positions of the motor shaft, the stator assembly is arranged around the rotor assembly, and the auxiliary winding is arranged around the auxiliary permanent magnet set.

2. The motor suitable for sensorless control according to claim 1, wherein the motor comprises a control device, the control device comprises a driving unit, a main control unit and a signal acquisition unit, and the driving unit drives the rotor assembly to rotate according to a control signal output by the main control unit; the signal acquisition unit is connected to the auxiliary winding and acquires signals of the auxiliary winding; and the main control unit adjusts the control signal output to the driving unit according to the signal of the auxiliary winding acquired by the signal acquisition unit.

3. The sensorless control compliant electric machine of claim 2 wherein the auxiliary permanent magnet stack is located at one end of the rotor assembly;

the stator assembly comprises a main stator iron core and a main winding wound on the main stator iron core, and the driving unit drives the rotor assembly to rotate by outputting driving voltage to the main winding; the motor auxiliary part comprises an auxiliary stator core, the auxiliary winding is wound on the auxiliary stator core, and the auxiliary stator core is located at one axial end of the auxiliary stator core.

4. The sensorless control compliant electric machine of claim 3 wherein the auxiliary stator core is integral with the main stator core.

5. The sensorless control compliant electric machine of claim 1 wherein the rotor assembly includes a main rotor core secured to the motor shaft; the motor auxiliary part comprises an auxiliary rotor core fixed on the motor shaft, and the auxiliary permanent magnet group is fixed on the auxiliary rotor core; the main rotor iron core and the auxiliary rotor iron core are separated by a magnetic isolation piece.

6. The machine adapted for sensorless control of claim 1 wherein the auxiliary windings are three phase ac windings connected in a star configuration and each two phase ac winding is 120 ° out of phase.

7. The motor adapted for sensorless control of claim 1 wherein the auxiliary winding comprises a first winding, a second winding, and a third winding, and wherein the phase difference between the first and second windings is 90 °, and wherein the third winding outputs a pulse signal for each rotation of the motor shaft.

8. The electric machine adapted for sensorless control of claim 4 wherein the rotor assembly further comprises a main rotor permanent magnet set assembled to the main rotor core, and wherein the permanent magnets in the auxiliary permanent magnet set are less magnetic than the permanent magnets in the main rotor permanent magnet set.

9. The machine adapted for sensorless control of claim 4 wherein the rotor assembly further comprises a main rotor permanent magnet set assembled to the main rotor core;

or the rotor assembly further comprises a rotor winding wound on the main rotor core.

10. The motor adapted for sensorless control according to any one of claims 1 to 9, wherein the motor further includes a motor housing, and the motor main body portion and the motor auxiliary portion are both provided in the motor housing.

Technical Field

The embodiment of the invention relates to the field of motor control, in particular to a motor suitable for sensorless control.

Background

The need for speed/position-less sensing control in industrial applications is becoming more prevalent. Compared with the traditional speed/position sensor control mode, the speed/position sensor is reduced due to the non-speed/position sensing control, so that the cost is reduced, and the potential reliability hazard brought by the speed/position sensor is reduced (in many industrial fields, the speed/position sensor is easy to break down due to the severe environment, such as oil stain, vibration impact, electromagnetic noise interference and other factors).

However, compared to the sensor control, the conventional speed/position sensorless control still has many problems to be solved, such as a general permanent magnet synchronous motor, no matter a method based on a motor model or a method based on high frequency injection, and is specifically embodied in the following aspects:

(1) the low speed performance is to be improved. Under the condition of low speed, the signal-to-noise ratio of a motor current signal is small, harmonic content caused by the influence of inverter dead zone nonlinearity and the like is high, so that the rotating speed and angle deviation estimated without speed/position sensing are large, and even the motor cannot stably run in severe cases.

(2) The parameters are susceptible to the operating environment. The motor parameters change along with the operating condition, such as the increase of a synchronous machine resistor along with the temperature of a winding, the nonlinear change of an inductor along with the load current, the decrease of a permanent magnet flux linkage along with the temperature increase and the like, the observation deviation of the rotating speed and the position can be caused, and even the observer is diverged to operate unstably in severe cases.

The existing speed/position-free sensing control mainly improves the stability, anti-interference performance, parameter robustness and the like of a speed/position-free observer from an algorithm theory level, and still does not well solve the problem of performance improvement of the existing speed/position-free sensing control at zero speed or low speed. Moreover, although the degree of change of the parameters of the motor body due to the influence of the environment and the operation condition can be reduced as much as possible by the application of a new material and a new process, the method is also limited by the material and the process, so that the problems of cost and the applicability of the motor type are relatively high, and the method is difficult to popularize in the industry.

Disclosure of Invention

The embodiment of the invention provides a motor suitable for non-sensing control, aiming at the problems of poor low-speed performance and easily influenced parameters by working environment in the non-speed/position sensing control scheme.

The embodiment of the invention provides a technical scheme for solving the technical problems, and the motor suitable for sensorless control comprises a motor main body part and a motor auxiliary part, wherein the motor main body part comprises a stator assembly, a rotor assembly and a motor shaft; the motor auxiliary part comprises an auxiliary winding and an auxiliary permanent magnet group; the rotor assembly and the auxiliary permanent magnet set are respectively fixed at different axial positions of the motor shaft, the stator assembly is arranged around the rotor assembly, and the auxiliary winding is arranged around the auxiliary permanent magnet set.

Preferably, the motor comprises a control device, the control device comprises a driving unit, a main control unit and a signal acquisition unit, and the driving unit drives the rotor assembly to rotate according to a control signal output by the main control unit; the signal acquisition unit is connected to the auxiliary winding and acquires signals of the auxiliary winding; and the main control unit adjusts the control signal output to the driving unit according to the signal of the auxiliary winding acquired by the signal acquisition unit.

Preferably, the auxiliary permanent magnet group is located at one end of the rotor assembly; the stator assembly comprises a main stator iron core and a main winding wound on the main stator iron core, and the driving unit drives the rotor assembly to rotate by outputting driving voltage to the main winding; the motor auxiliary part comprises an auxiliary stator core, the auxiliary winding is wound on the auxiliary stator core, and the auxiliary stator core is located at one axial end of the auxiliary stator core.

Preferably, the auxiliary stator core is integrated with the main stator core.

Preferably, the rotor assembly includes a main rotor core fixed on the motor shaft; the motor auxiliary part comprises an auxiliary rotor core fixed on the motor shaft, and the auxiliary permanent magnet group is fixed on the auxiliary rotor core; the main rotor iron core and the auxiliary rotor iron core are separated by a magnetic isolation piece.

Preferably, the auxiliary winding is a three-phase ac winding connected in a star-like manner, and a phase difference of each two-phase ac winding is 120 °.

Preferably, the auxiliary winding includes a first winding, a second winding and a third winding, and the phase difference between the first winding and the second winding is 90 °, and the third winding outputs a pulse signal for each rotation of the motor shaft.

Preferably, the rotor assembly further comprises a main rotor permanent magnet group assembled to the main rotor core, and the permanent magnets in the auxiliary permanent magnet group have a magnetic property weaker than that of the permanent magnets in the main rotor permanent magnet group.

Preferably, the rotor assembly further comprises a main rotor permanent magnet set fitted to the main rotor core; or the rotor assembly further comprises a rotor winding wound on the main rotor core.

Preferably, the motor further includes a motor casing, and the motor main body portion and the motor auxiliary portion are both disposed in the motor casing.

According to the motor suitable for sensorless control, the auxiliary permanent magnet group and the auxiliary winding which are independent of the main body part of the motor are arranged, so that an auxiliary speed/position signal can be generated in the operation process of the main body part of the motor, the speed/position sensorless control is more accurate and reliable in a low-speed section, and the difficulty that a speed sensorless observer cannot meet application requirements in the low-speed section is overcome. Compared with the conventional scheme of adding a speed/position sensor, the speed/position sensor has the advantages of lower design cost, higher reliability and simple application.

Drawings

FIG. 1 is a schematic diagram of a motor suitable for sensorless control according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an auxiliary stator core for a sensorless controlled electric machine according to an embodiment of the present invention;

fig. 3 is a schematic diagram of an auxiliary rotor core and an auxiliary permanent magnet set in a motor suitable for sensorless control according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention improves the existing motor from the angle of the motor body, can provide auxiliary information for a control device under the condition of low speed so as to correct the rotating speed, the angle observation deviation and the like, is particularly suitable for occasions without speed/position sensors, and is particularly suitable for accurate control during low-speed running.

Fig. 1-3 are schematic diagrams of a motor suitable for sensorless control according to an embodiment of the present invention, which can operate accurately and stably without a speed/position sensor providing a feedback signal. The motor suitable for speed/position-free sensing control of the embodiment comprises a motor main body part 1 and a motor auxiliary part 2, torque output is realized through the motor main body part 1, and operation parameters (such as rotating speed, position and the like) of the motor main body part 1 are collected through the motor auxiliary part 2, so that the operation of the motor main body part 1 can be accurately controlled. In order not to increase the volume of the whole machine, the motor auxiliary part 2 may have a smaller volume, and the motor auxiliary part 2 may be located at the tail end of the motor main body part 1 (i.e., the end away from the torque output side of the motor main body part 1) so as not to affect the torque output. Particularly, the motor can further comprise a motor shell, and the motor main body part and the motor auxiliary part are arranged in the motor shell, so that the integration level of the whole machine is improved, and the cost is reduced.

Similarly to the existing motor, the motor main body 1 includes a stator assembly 11, a rotor assembly 12, and a motor shaft 13, and torque output is achieved by the stator assembly 11, the rotor assembly 12, and the motor shaft 13. The motor auxiliary 2 includes an auxiliary winding 212 and an auxiliary permanent magnet group 221 (the auxiliary permanent magnet group 221 may include a plurality of permanent magnets). The rotor assembly 12 and the auxiliary permanent magnet group 221 are respectively fixed at different axial positions of the motor shaft 13 (for example, in fig. 1, the rotor assembly 12 is located at the left end of the motor shaft 13, the auxiliary permanent magnet group 221 is located at the right end of the motor shaft 13, the auxiliary permanent magnet group 221 may include a plurality of permanent magnets that are alternately arranged in polarity to surround the motor shaft 13), the stator assembly 11 is disposed around the rotor assembly 12, and the auxiliary winding 212 is disposed around the auxiliary permanent magnet group 221.

When the rotor assembly 12 rotates the motor shaft 13 and outputs torque, the auxiliary permanent magnet set 221 rotates along with the motor shaft 13, and the angular velocity of the rotation of the auxiliary permanent magnet set 221 is the same as the angular velocity of the rotation of the motor shaft 13. The auxiliary permanent magnet set 221 generates a changing magnetic field in the rotating process, the auxiliary winding 212 surrounding the auxiliary permanent magnet set 221 generates an induced current due to an alternating magnetic field, the induced current includes the rotating characteristic of the motor shaft 13, and the operating parameters of the motor shaft 13 and the rotor assembly 12 can be obtained by detecting signals (voltage and/or current) in the auxiliary winding 212, so that the rotating speed, the angle observation deviation and the like of the motor main body 1 can be corrected conveniently. Since there is no drive signal in the auxiliary winding 212 and thus no harmonics generated by the power module switches are included, the signal in the auxiliary winding 212 is more accurate than the signal collected from the motor body 1, especially when the rotor assembly 12 of the motor body 1 is operating at low speed.

The motor suitable for speed/position sensorless control can generate auxiliary speed/position signals in the running process of the motor main body part 1 through the auxiliary permanent magnet group 221 and the auxiliary winding 212 which are independent of the motor main body part 1, so that the speed/position sensorless control is more accurate and reliable in a low-speed section, and the difficulty that a speed/position sensorless observer cannot meet application requirements in the low-speed section is overcome. Compared with the existing speed/position sensor, the parameters of the permanent magnet group 221 and the auxiliary winding 212 are less influenced by the environment and the operation condition, and the anti-interference performance is stronger.

In an embodiment of the present invention, the motor adapted for non-speed/position sensing control may further include a control device, where the control device includes a driving unit, a main control unit and a signal acquisition unit, and the driving unit drives the rotor assembly to rotate according to a control signal output by the main control unit; the signal acquisition unit is connected to the auxiliary winding and acquires signals (voltage or current) of the auxiliary winding to provide for the main control unit, and the main control unit adjusts control signals output to the driving unit according to the signals of the auxiliary winding acquired by the signal acquisition unit so as to correct the rotating speed, the angle observation deviation and the like of the motor main body part 1. In practical applications, the control device may be integrated into the motor, but of course the control device may also be independent of the motor.

In particular, the control device can adopt a conventional speed/position observer to observe and feedback control the rotating speed and the angle information in the normal, medium and high speed stage when the control device carries out speed/position-free sensing control, and can adopt the signal in the auxiliary winding 212 to observe and feedback control the rotating speed and the angle information in the low speed stage. Of course, during normal high speed, the control device may also use the signal in the auxiliary winding 212 to perform observation and feedback control on the rotation speed and angle information.

In another embodiment of the present invention, the auxiliary permanent magnet set 221 may be located at one end of the rotor assembly 12, for example, the end away from the output side of the motor shaft 13. The stator assembly 11 includes a main stator core 111 and a main winding 112 wound on the main stator core 111, and the driving unit of the control device drives the rotor assembly 12 to rotate by outputting a driving voltage to the main winding 112. Accordingly, the motor auxiliary part 2 includes an auxiliary stator core 211 for winding the auxiliary winding 212, and the auxiliary stator core 211 is located at one end in the axial direction of the main stator core 111 (the auxiliary stator core 211 is coaxial with the main stator core 111), and the axial length of the auxiliary stator core 211 is much smaller than the axial length of the main stator core 111.

Preferably, the auxiliary stator core 211 may be integrated with the main stator core 111, so as to facilitate the manufacturing of the motor of the present embodiment and save the cost. Of course, in practical applications, the auxiliary stator core 211 and the main stator core 111 may be independent from each other and assembled together after the auxiliary winding 212 and the main winding 112 are wound.

The rotor assembly 12 may specifically include a main rotor core fixed to the motor shaft 13; the motor auxiliary part 2 includes an auxiliary rotor core 22 fixed on the motor shaft 13, and the auxiliary permanent magnet group 221 is fixed on the auxiliary rotor core 22, and the main rotor core and the auxiliary rotor core 22 are separated by a magnetic separation member 23. The magnetic isolation member 23 may be made of a magnetic isolation material, and the magnetic isolation member 23 may be fixed to the motor shaft 13. Through the magnetism isolating piece 23, the magnetic field of the auxiliary permanent magnet group 221 can be prevented from interfering the magnetic field in the motor main body part 1, so that the motor auxiliary part 2 can not affect the normal operation of the motor main body part 1.

In particular, in the motor, there is no special requirement for the size, structure, number of stator slots 2111, and the like of the auxiliary stator core 211; similarly, the size, structure, number of magnetic poles, and the like of the auxiliary rotor core are not particularly limited, and the auxiliary winding 212 may be induced to generate an induction current.

The auxiliary winding 212 may be three-phase ac windings connected in a star-like manner, and each two-phase ac winding has a phase difference of 120 °, and the connection method is similar to that of a conventional permanent magnet synchronous motor. When the auxiliary permanent magnet group 221 rotates along with the motor shaft 13, the magnetic field generated by the auxiliary permanent magnet group cuts the auxiliary winding 212, so that a three-phase symmetrical voltage signal is generated in the auxiliary winding 212, the voltage signal contains sine or cosine information of the angle of the magnetic field, and a main control unit of the control device can acquire the angle information of the magnetic field through an angle information extraction algorithm and can also acquire the rotating speed information of the rotor so as to adjust corresponding control quantity.

In addition, the above-mentioned auxiliary winding 212 may also adopt a three-phase direct current winding, that is, the auxiliary winding 212 includes a first winding (i.e., a winding), a second winding (i.e., B winding), and a third winding (i.e., Z winding), and the phase difference between the first winding and the second winding is 90 °, and the third winding outputs a pulse signal at every rotation of the motor shaft as a calibration signal for the number of rotations of the motor shaft 13. The electric signals of the three-phase direct current windings are similar to ABZ pulse signals in an ABZ encoder, the rotating speed information and the positive and negative rotation information of the motor shaft 13 can be obtained through the frequency and the phase difference of the electric signals of the first winding and the second winding, meanwhile, the angle information can be obtained, and the number of rotation turns of the motor shaft 13 can be calibrated through the electric signals of the third winding.

In one embodiment of the present invention, the motor adapted for non-speed/position sensing control as described above may be a permanent magnet synchronous motor, and accordingly, the rotor assembly 12 includes, in addition to the main rotor core, a main rotor permanent magnet set assembled to the main rotor core.

Unlike the main rotor permanent magnet set, the magnetic field generated by the auxiliary permanent magnet set 221 does not contribute to the torque output of the motor shaft 13, and the magnetic field only serves to generate an auxiliary electrical signal with a certain strength for cutting the auxiliary winding 212, so that the rotation speed and angle information can be extracted from the auxiliary electrical signal, and therefore, the magnetism of the permanent magnets in the auxiliary permanent magnet set 221 can be weaker than that of the permanent magnets in the main rotor permanent magnet set. For example, the permanent magnets in the auxiliary permanent magnet set 221 may be weak permanent magnets or low-cost low-performance permanent magnets (such as ferrite material, other soft magnetic material, etc.) with similar functions.

The motor suitable for the non-speed/position sensing control may also be an asynchronous motor, an electrically excited synchronous motor, or the like, and accordingly, the rotor assembly 12 includes a rotor winding wound around the main rotor core in addition to the main rotor core. Furthermore, the motor suitable for the non-speed/position sensing control may be a synchronous reluctance motor or other type of motor.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.