阅读说明：本技术 多极电机转子绝对位置无传感器控制方法 (Sensorless control method for absolute position of multi-pole motor rotor ) 是由 倪荣刚 于 2020-12-09 设计创作，主要内容包括：本发明公开了多极电机转子绝对位置无传感器控制方法,基于双定子电机结构,限定两个电机单元的极对数p1和p2满足互质且|m×p1-n×p2|＝1的条件,将双定子电机在一个机械周期内的对应关系限定为无重复性,从而能够根据这种无重复性的对应关系计算得到转子绝对角度位置观测值θ-m,进而能够根据转子绝对角度位置观测值θ-m推导出控制功率电路的两路开关信号S-1和S-2,使得功率电路采用该两路开关信号S-1和S-2来驱动双定子电机,实现了一种无需额外安装位置传感器,仅通过逆变器的电压、电流等已知信息辨识得到转子绝对角度位置的方法,具有低成本、高集成度和高可靠性等优点。(The invention discloses a sensor-free control method for the absolute position of a multi-pole motor rotor, which is based on a double-stator motor structure, limits the number of pole pairs p1 and p2 of two motor units to meet the condition of being relatively prime and | m × p1-n × p2| ═ 1, and limits the corresponding relation of the double-stator motor in one mechanical period to be non-repeatability, so that the observed value theta of the absolute angle position of the rotor can be calculated and obtained according to the non-repeatability corresponding relation m And further, the observation value theta can be obtained from the absolute angular position of the rotor m Deducing two-way switch signal S for controlling power circuit 1 And S 2 So that the power circuit adopts the two paths of switching signals S 1 And S 2 The method for driving the double-stator motor realizes the method for obtaining the absolute angle position of the rotor only through known information identification such as voltage, current and the like of the inverter without additionally installing a position sensor, and has the advantages of low cost, high integration degree, high reliability and the like.)

1. A multi-pole motor rotor absolute position sensorless control method is applied to a multi-pole motor rotor absolute position sensorless control system, and the system comprises:

the double-stator motor is composed of a first motor unit and a second motor unit which are coaxial, wherein the first motor unit is composed of a first stator and a first pole pair number p1, and the second motor unit is composed of a second stator and a second pole pair number p 2; the first pole pair number p1 and the second pole pair number p2 satisfy: p1 ≠ p2, the greatest common divisor of p1 and p2 is 1, and | m × p1-n × p2| ═ 1, m, n, p1, and p2 are positive integers;

a power circuit for generating a first switching signal S₁And a second switching signal S₂Respectively driving the first motor unit and the second motor unit to operate under the control of the controller;

the control method is characterized by comprising the following steps:

based on the first switching signal S₁Line current i of the first motor unit₁And bus voltage u_dcObtaining an observed rotor electrical angular position θ of the first motor unit_e1And observing the rotor electrical angular velocity omega_e1(ii) a Based on the second switching signal S₂Line current i of the second motor unit₂And bus voltage u_dcObtaining an observed rotor electrical angular position θ of the second motor unit_e2And observing the rotor electrical angular velocity omega_e2；

Observation rotor electrical angle position theta based on first motor unit_e1And observed rotor electrical angular position θ of the second motor unit_e2Obtaining the observed value theta of the absolute angle position of the rotor_m；

Observed value theta based on rotor absolute angle position_mAnd rotor absolute angular position reference valueObtaining the mechanical rotating speed reference value of the rotor

Based on rotor mechanical speed referenceAnd observing the rotor electrical angular velocity omega_e1Generating the first switching signal S₁Based on a reference value of the mechanical rotational speed of the rotorAnd observing the rotor electrical angular velocity omega_e2Generating the second switching signal S₂。

2. The method of claim 1, wherein the sensorless control of the absolute position of the rotor of the multi-pole motor is based on the view of the first motor unitMeasuring the electrical angular position theta of the rotor_e1And observed rotor electrical angular position θ of the second motor unit_e2Obtaining the observed value theta of the absolute angle position of the rotor_mThe method specifically comprises the following steps:

calculating an observed rotor electrical angular position θ of the first motor unit_e1The first sine value sin (m θ) of the product with m_e1) And a first cosine value cos (m θ)_e1) (ii) a Calculating an observed rotor electrical angular position θ of the second motor unit_e2A second sine value sin (n θ) of the product with n_e2) And a second cosine value cos (n θ)_e2)；

From the first sine value sin (m θ)_e1) And a second cosine value cos (n θ)_e2) Product of (d) and a first cosine value cos (m θ)_e1) And a second sine value sin (n θ)_e2) The difference of the products of the two methods is used for obtaining the sine value sin theta of the observed value of the absolute angle position of the rotor_m(ii) a From the first sine value sin (m θ)_e1) With a second sine value sin (n θ)_e2) Product of (d) and a first cosine value cos (m θ)_e1) And a second cosine value cos (n θ)_e2) The cosine value cos theta of the observed value of the absolute angle position of the rotor is obtained by the sum of the products_m；

Sine value sin theta according to observed value of absolute angle position of rotor_mAnd cosine value cos θ_mCalculating the arc tangent or obtaining the observed value theta of the absolute angle position of the rotor through a phase-locked loop_m。

3. The method of claim 1, wherein the observed rotor electrical angular position θ based on the first motor unit is determined by a position sensor based on the absolute position of the rotor of the multi-pole motor_e1And observed rotor electrical angular position θ of the second motor unit_e2Obtaining the observed value theta of the absolute angle position of the rotor_mThe method specifically comprises the following steps:

calculating an observed rotor electrical angular position θ of the first motor unit_e1Product of m and observed rotor electrical angle position theta of second motor unit_e2The difference of the product of n and n is used to obtain the observed value theta of the absolute angle position of the rotor_m。

4. Root of herbaceous plantMethod for sensorless control of the absolute position of the rotor of a multipole motor according to claim 1, characterized in that the observed rotor electrical angular position θ of said first motor unit_e1And observing the rotor electrical angular velocity omega_e1And an observed rotor electrical angular position θ of the second motor unit_e2And observing the rotor electrical angular velocity omega_e2All are obtained by the control without a position sensor.

5. Method for sensorless control of the absolute position of the rotor of a multipole motor according to claim 1, characterized in that said rotor mechanical rotation speed reference valueObtained by the position loop controller.

6. Method for sensorless control of the absolute position of the rotor of a multipole motor according to claim 1, characterized in that it is based on a rotor mechanical rotation speed referenceAnd observing the rotor electrical angular velocity omega_e1Generating the first switching signal S₁Based on a reference value of the mechanical rotational speed of the rotorAnd observing the rotor electrical angular velocity omega_e2Generating the second switching signal S₂The method specifically comprises the following steps:

based on the first pole pair number p1 and the rotor mechanical rotation speed reference valueThe product of which yields the reference value of the electrical angular velocity of the rotor of the first motor unitBased on the second pole pair number p2 and the reference value of the rotor mechanical speedThe product of which yields the reference value of the electrical angular velocity of the rotor of the second motor unit

Reference value of rotor electrical angular velocity based on first motor unitAnd observing the electrical angular velocity omega of the rotor_e1Generating the first switching signal S₁(ii) a Reference value of rotor electrical angular velocity based on second motor unitAnd observing the electrical angular velocity omega of the rotor_e2Generating the second switching signal S₂。

7. Method for sensorless control of the absolute position of the rotor of a multipole motor according to claim 1 or 6, characterized in that said first switching signal S₁Obtained as follows:

reference value for the electrical angular speed of the rotor of the first motor unitAnd observing the electrical angular velocity omega of the rotor_e1Obtaining a current loop reference value of the first motor unit via the speed loop controllerReference value of the current loop of the first motor unitLine current i₁And observing the rotor electrical angular position theta_e1Obtaining a voltage reference value of the first motor unit via a current loop controllerVoltage reference value of the first motor unitObtaining the first switching signal S after modulation₁；

The second switching signal S₂Obtained as follows:

reference value of rotor electrical angular velocity of second motor unitAnd observing the electrical angular velocity omega of the rotor_e2Obtaining a current loop reference value of the second motor unit via the speed loop controllerCurrent loop reference value of the second motor unitLine current i₂And observing the rotor electrical angular position theta_e2Obtaining a voltage reference value of the second motor unit via the current loop controllerVoltage reference value of the second motor unitObtaining the second switching signal S after modulation₂。

8. The method of sensorless control of absolute position of a rotor of a multi-pole motor of claim 1, further comprising:

when the rotor axes of the first electrode unit and the second motor unit are not aligned, the absolute angle position deviation delta theta of the axes is adopted_mAnd compensating the observed value of the absolute angle position of the rotor.

Technical Field

The invention belongs to the technical field of motor control, and particularly relates to a sensorless control method for the absolute position of a multi-pole motor rotor.

Background

Modern high-end equipment such as numerical control machine tools, intelligent household appliances and robots require a motor driving system to have the capability of detecting the absolute angular position (also called mechanical angular position) of a rotor.

Unlike conventional detection of the relative angular position (also called electrical angular position) of the rotor, which can be realized by a position sensor or by control without a position sensor, the absolute angular position of the rotor of the motor must be detected by an absolute position sensor at present due to the periodic symmetry of the electromagnetic structure inside the motor. However, the absolute position sensor is expensive, the encoding and signal transmission modes are complex, and the installation position sensor occupies the axial space of the motor, so that the power density, the integration level and the reliability of the system are reduced.

In the current research on sensorless control of the absolute angular position of the rotor, there are a few published technical solutions at seoul university in korea, which artificially manufacture the asymmetry of the mechanical cycle by modifying the structure of the stator and the rotor of the motor, add a detection winding in the stator, and identify the asymmetry of the mechanical cycle by combining a high-frequency voltage injection method, thereby obtaining the absolute position of the rotor. However, when the mechanical period asymmetry of the motor is artificially manufactured, the winding inductance and the counter electromotive force harmonic are correspondingly increased, new problems of torque ripple, vibration noise and the like are caused, and the balance between the motor performance and the absolute position detection precision is difficult. Moreover, the additional detection winding occupies the stator space, which is not favorable for improving the power density.

Disclosure of Invention

The invention aims to provide a multipolar motor rotor absolute position sensorless control method, which is based on a double-stator motor structure, improves the control dimension of a motor system by means of limiting the pole-to-pair relation of two motor units, constructs a full rank coefficient matrix related to a rotor position angle, obtains the rotor absolute position only through known information such as voltage, current and the like of an inverter, does not need to additionally install a position sensor, does not need to artificially manufacture the asymmetry of a mechanical period, does not cause adverse effect on the motor performance while realizing the sensorless control, and is favorable for improving the power density, the integration level and the reliability of the motor system.

In order to solve the technical problems, the invention adopts the following technical scheme:

a multi-pole motor rotor absolute position sensorless control method is provided, which is applied to a multi-pole motor rotor absolute position sensorless control system, and the system comprises: the double-stator motor is composed of a first motor unit and a second motor unit which are coaxial, wherein the first motor unit is composed of a first stator and a first pole pair numberp1, the second motor unit consisting of a second stator and a second pole pair number p 2; the first pole pair number p1 and the second pole pair number p2 satisfy: p1 ≠ p2, the greatest common divisor of p1 and p2 is 1, and | m × p1-n × p2| ═ 1, m, n, p1, and p2 are positive integers; a power circuit for generating a first switching signal S₁And a second switching signal S₂Respectively driving the first motor unit and the second motor unit to operate under the control of the controller; the control method comprises the following steps: based on the first switching signal S₁Line current i of the first motor unit₁And bus voltage u_dcObtaining an observed rotor electrical angular position θ of the first motor unit_e1And observing the rotor electrical angular velocity omega_e1(ii) a Based on the second switching signal S₂Line current i of the second motor unit₂And bus voltage u_dcObtaining an observed rotor electrical angular position θ of the second motor unit_e2And observing the rotor electrical angular velocity omega_e2(ii) a Observation rotor electrical angle position theta based on first motor unit_e1And observed rotor electrical angular position θ of the second motor unit_e2Obtaining the observed value theta of the absolute angle position of the rotor_m(ii) a Observed value theta based on rotor absolute angle position_mAnd rotor absolute angular position reference valueObtaining the mechanical rotating speed reference value of the rotorBased on rotor mechanical speed referenceAnd observing the rotor electrical angular velocity omega_e1Generating the first switching signal S₁Based on a reference value of the mechanical rotational speed of the rotorAnd observing the rotor electrical angular velocity omega_e2Generating the second switching signal S₂。

Further, a groupObserving the rotor electrical angular position θ in the first motor unit_e1And observed rotor electrical angular position θ of the second motor unit_e2Obtaining the observed value theta of the absolute angle position of the rotor_mThe method specifically comprises the following steps: calculating an observed rotor electrical angular position θ of the first motor unit_e1The first sine value sin (m θ) of the product with m_e1) And a first cosine value cos (m θ)_e1) (ii) a Calculating an observed rotor electrical angular position θ of the second motor unit_e2A second sine value sin (n θ) of the product with n_e2) And a second cosine value cos (n θ)_e2) (ii) a From the first sine value sin (m θ)_e1) And a second cosine value cos (n θ)_e2) Product of (d) and a first cosine value cos (m θ)_e1) And a second sine value sin (n θ)_e2) The difference of the products of the two methods is used for obtaining the sine value sin theta of the observed value of the absolute angle position of the rotor_m(ii) a From the first sine value sin (m θ)_e1) With a second sine value sin (n θ)_e2) Product of (d) and a first cosine value cos (m θ)_e1) And a second cosine value cos (n θ)_e2) The cosine value cos theta of the observed value of the absolute angle position of the rotor is obtained by the sum of the products_m(ii) a Sine value sin theta according to observed value of absolute angle position of rotor_mAnd cosine value cos θ_mCalculating the arc tangent or obtaining the observed value theta of the absolute angle position of the rotor through a phase-locked loop_m。

Further, based on the observed rotor electrical angle position θ of the first motor unit_e1And observed rotor electrical angular position θ of the second motor unit_e2Obtaining the observed value theta of the absolute angle position of the rotor_mThe method specifically comprises the following steps: calculating an observed rotor electrical angular position θ of the first motor unit_e1Product of m and observed rotor electrical angle position theta of second motor unit_e2The difference of the product of n and n is used to obtain the observed value theta of the absolute angle position of the rotor_m。

Further, the observed rotor electrical angle position θ of the first motor unit_e1And observing the rotor electrical angular velocity omega_e1And an observed rotor electrical angular position θ of the second motor unit_e2And observing the rotor electrical angular velocity omega_e2All are obtained by the control without a position sensor.

Further, the rotor mechanical rotation speed reference valueObtained by the position loop controller.

Further, based on the reference value of the rotor mechanical speedAnd observing the rotor electrical angular velocity omega_e1Generating the first switching signal S₁Based on a reference value of the mechanical rotational speed of the rotorAnd observing the rotor electrical angular velocity omega_e2Generating the second switching signal S₂The method specifically comprises the following steps: based on the first pole pair number p1 and the rotor mechanical rotation speed reference valueThe product of which yields the reference value of the electrical angular velocity of the rotor of the first motor unitBased on the second pole pair number p2 and the reference value of the rotor mechanical speedThe product of which yields the reference value of the electrical angular velocity of the rotor of the second motor unitReference value of rotor electrical angular velocity based on first motor unitAnd observing the electrical angular velocity omega of the rotor_e1Generating the first switching signal S₁(ii) a Reference value of rotor electrical angular velocity based on second motor unitAnd observing the electrical angular velocity omega of the rotor_e2Generating the second switching signal S₂。

Further, the first switching signal S₁Obtained as follows: reference value for the electrical angular speed of the rotor of the first motor unitAnd observing the electrical angular velocity omega of the rotor_e1Obtaining a current loop reference value of the first motor unit via the speed loop controllerReference value of the current loop of the first motor unitLine current i₁And observing the rotor electrical angular position theta_e1Obtaining a voltage reference value of the first motor unit via a current loop controllerVoltage reference value of the first motor unitObtaining the first switching signal S after modulation₁(ii) a The second switching signal S₂Obtained as follows: reference value of rotor electrical angular velocity of second motor unitAnd observing the electrical angular velocity omega of the rotor_e2Obtaining a current loop reference value of the second motor unit via the speed loop controllerCurrent loop reference value of the second motor unitLine current i₂And observing the electrical angular position of the rotorθ_e2Obtaining a voltage reference value of the second motor unit via the current loop controllerVoltage reference value of the second motor unitObtaining the second switching signal S after modulation₂。

Further, the method further comprises: when the rotor axes of the first electrode unit and the second motor unit are not aligned, the absolute angle position deviation delta theta of the axes is adopted_mAnd compensating the observed value of the absolute angle position of the rotor.

Compared with the prior art, the invention has the advantages and positive effects that: in the sensorless control method for the absolute position of the rotor of the multi-pole motor, based on the structure of the double-stator motor, the pole pair numbers p1 and p2 of two motor units are limited to meet the conditions that the p1 is not equal to the p2, the greatest common divisor of the p1 and the p2 is 1, and | m × p1-n × p2| is 1, the corresponding relation of the double-stator motor in one mechanical period is limited to be non-repeatability, and the observed value theta of the absolute angle position of the rotor can be obtained through calculation according to the non-repeatability corresponding relation_mAnd further, the observation value theta can be obtained from the absolute angular position of the rotor_mDeducing two-way switch signal S for controlling power circuit₁And S₂So that the power circuit adopts the two paths of switching signals S₁And S₂The method for driving the double-stator motor has the advantages of low cost, high integration degree, high reliability and the like, is beneficial to realizing more power integration in a limited space, and improves the power density of the motor.

Other features and advantages of the present invention will become more apparent from the detailed description of the embodiments of the present invention when taken in conjunction with the accompanying drawings.

Drawings

FIG. 1 is a radial cross-sectional view of a dual stator motor with radial coaxiality in a sensorless control system for absolute rotor position of a multi-pole motor according to the present invention;

FIG. 2 is an axial cross-sectional view of a double-stator motor with coaxial axial axes in the multi-pole motor rotor absolute position sensorless control system according to the present invention;

FIG. 3 illustrates an embodiment of sensorless control of absolute rotor position for a multi-pole motor according to the present invention;

FIG. 4 is a flow chart of a sensorless control method for absolute rotor position of a multi-pole motor according to the present invention;

FIG. 5 is a block diagram of a closed-loop control system for a sensorless control method of absolute position of a multi-pole motor rotor in accordance with the present invention;

FIG. 6 is a diagram of yet another embodiment of sensorless control of absolute rotor position for a multi-pole motor in accordance with the present invention;

FIG. 7 is a block diagram of an embodiment of a dual three-phase inverter circuit according to the present invention;

FIG. 8 is a structural diagram of a dual three-phase inverter circuit according to a second embodiment of the present invention;

FIG. 9 is a schematic view of an axial coaxial dual stator motor with its central axes not fully aligned;

fig. 10 is a schematic diagram of the effect of closed-loop control of absolute rotor position sensorless control of a multi-pole motor according to the present invention.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

As is well known to those skilled in the art, when a rotor of an electric machine rotates for 1 mechanical cycle, the number of magnetic field alternations passed by a stator is related to the number of pole pairs, and when only the number of pole pairs p is 1, the absolute position of the rotor of the electric machine is equal to the relative position, whereas when p >1, the magnetic field distributions of two or more mechanical angles are completely the same in one mechanical cycle, and at this time, if an absolute position sensor is not used, the absolute position of the rotor cannot be known only from the voltage and current information in the stator conductor.

The invention aims to improve the control dimension of a motor system by limiting the relation of the pole pair number of two motor units based on a double-stator motor structure without additionally installing an absolute position sensor or artificially manufacturing the asymmetry of a mechanical period, construct a full-rank coefficient matrix related to the position angle of a rotor, and obtain the absolute position of the rotor only through the known information such as the voltage, the current and the like of an inverter.

Specifically, as shown in fig. 1 and 2, the double-stator motor structure based on the present invention is composed of a first motor unit and a second motor unit which are coaxial, wherein the first motor unit is composed of a first stator 1 and a first pole pair number p1, and the second motor unit is composed of a second stator 2 and a second pole pair number p 2.

In the application of the invention, the coaxial first motor unit and the coaxial second motor unit comprise two conditions of radial coaxiality and axial coaxiality; as shown in fig. 1, the first pole pair number p1 and the second pole pair number p2 are embedded in the same rotor 3 when they are radially coaxial; as shown in fig. 2, when the first motor unit and the second motor unit are axially coaxial, the first pole pair p1 is embedded in the first rotor 31, the second pole pair p2 is embedded in the second rotor 32, and the first rotor 31 and the second rotor 32 are coaxially connected.

The invention adopts a mode of limiting the values of the first pole pair number p1 and the second pole pair number p2 to improve the control dimension of the motor system, constructs a full rank coefficient matrix related to the position angle of the rotor, and obtains the absolute angle position of the rotor according to the corresponding relation between the electric angle position of the first motor unit and the electric angle position of the second motor unit.

Specifically, the present invention defines that the first pole pair number p1 and the second pole pair number p2 satisfy the following relation definition: 1. the first pole pair number p1 and the second pole pair number p2 are relatively prime, i.e., the greatest common divisor of p1 ≠ p2, p1 and p2 is 1, and 2, | m × p1-n × p2| ═ 1, m, n, p1 and p2 are all positive integers.

For example, when p1 is 2 and ρ is 3, the two are mutually prime, and when m is 2 and n is 1, the limit of | m × p1-n × p2| 1 is satisfied, and then, in one mechanical cycle, as shown in fig. 3, under the limit condition, any one mechanical angular position, the rotor electrical angular position θ of the first motor unit_e1And the rotor electrical angle position theta of the second motor unit_e2Are different, the absolute angular position of the rotor can be calculated based on this asymmetry of the mechanical period.

Based on the above, the sensorless control method for the absolute position of the rotor of the multi-pole motor, which is provided by the present invention and shown in fig. 4 and 5, includes the following steps:

step S41: based on the first switching signal S₁Line current i of the first motor unit₁Obtaining the observed rotor electrical angular position theta of the first motor unit from the bus voltage udc_e1And observing the rotor electrical angular velocity omega_e1(ii) a Based on the second switching signal S₂Line current i of the second motor unit₂And bus voltage u_dcObtaining an observed rotor electrical angular position θ of the second motor unit_e2And observing the rotor electrical angular velocity omega_e2。

The control method of the present invention, as shown in fig. 5, uses a current loop controller 1 and a current loop controller 2 to generate a first switching signal S for controlling a first motor unit and a second motor unit, respectively₁And a second switching signal S₂At a first switching signal S by the power circuit₁And a second switching signal S₂Respectively drive the first motor unit and the second motor unit to operate under the control of the controller.

In the power circuit, the AC input is rectified to obtain a stable bus voltage u_dcOr the stable bus voltage udc is directly obtained by direct current power supply to supply power for the double three-phase inverter circuit; double three-phase inverter circuit for generating first switching signal S₁And a second switching signal S₂Respectively drive the first motor unit and the second motor unit to operate under the control of the controller.

This step is performed by a first switching signal S₁The sampled line current i of the first motor unit₁And bus voltage u_dcObtaining the observed rotor electrical angular position θ of the first motor unit via conventional position sensorless control 1_e1And observing the rotor electrical angular velocity omega_e1(ii) a By means of a second switching signal S₂Sampled line current i of the second motor unit₂And bus voltage u_dcConventional position sensorless control2 obtaining an observed rotor electrical angular position θ of the second motor unit_e2And observing the rotor electrical angular velocity omega_e2。

In the conventional position sensorless control, a model method based on counter potential observation is adopted when the motor runs at a high speed, an auxiliary voltage injection method is adopted when the motor runs at a low speed or even runs at zero speed, and the injection voltage can be high frequency or low frequency, can be injected under a stationary coordinate axis system or a rotating coordinate axis system.

Step S42: observation rotor electrical angle position theta based on first motor unit_e1And observed rotor electrical angular position θ of the second motor unit_e2Obtaining the observed value theta of the absolute angle position of the rotor_m。

Example one

Due to theta_e1＝p1θ_m，θ_e2＝p2θ_mAnd based on the defined relationship in the present invention: p1 and p2 satisfy | m × p1-n × p2| ═ 1, and in this example, m × p1-n × p2 ═ 1, m × θ can be obtained_e1-n×θ_e2＝m×p1θ_m-n×p2θ_m＝(m×p1-n×p2)θ_m＝θ_m。

In the present embodiment, the observed rotor electrical angle position θ of the first motor unit is calculated_e1Product of m and m x theta_e1Observed rotor electrical angular position θ with the second motor unit_e2Product n x theta with n_e2Difference m x theta_e1-n×θ_e2Obtaining the observed value theta of the absolute angle position of the rotor_m。

Example two

This embodiment is suitable for phase locked loop applications, based on the principles described in the first embodiment, as shown in fig. 6, and the observed value θ of the absolute angular position of the rotor is as follows_m。

1. Calculating an observed rotor electrical angular position θ of the first motor unit_e1The first sine value sin (m θ) of the product with m_e1) And a first cosine value cos (m θ)_e1) (ii) a Calculating an observed rotor electrical angular position θ of the second motor unit_e2A second sine value sin (n θ) of the product with n_e2) And a secondCosine value cos (n θ)_e2)。

2. From the first sine value sin (m θ)_e1) And a second cosine value cos (n θ)_e2) Sin (m θ) of_e1)cos(nθ_e2) With a first cosine value cos (m θ)_e1) And a second sine value sin (n θ)_e2) Cos (m θ) of_e1)sin(nθ_e2) Difference sin (m θ)_e1)cos(nθ_e2)-cos(mθ_e1)sin(nθ_e2) Obtaining the sine value sin theta of the observed value of the absolute angle position of the rotor_m(ii) a From the first sine value sin (m θ)_e1) With a second sine value sin (n θ)_e2) Sin (m θ) of_e1)sin(nθ_e2) With a first cosine value cos (m θ)_e1) And a second cosine value cos (n θ)_e2) Cos (m θ) of_e1)cos(nθ_e2) Sum sin (m θ)_e1)sin(nθ_e2)+cos(mθ_e1)cos(nθ_e2) Obtaining cosine value cos theta of observed value of absolute angle position of rotor_m。

3. Sine value sin theta according to observed value of absolute angle position of rotor_mAnd cosine value cos θ_mCalculating the arc tangent or obtaining the observed value theta of the absolute angle position of the rotor through a phase-locked loop_m。

EXAMPLE III

In this embodiment, the absolute angular position observation θ of the rotor is obtained by a stored set relationship through a query method_m。

As shown in fig. 3, which is an example of a relationship diagram of an absolute angle and an electrical angle position of a rotor of an electric motor in one mechanical cycle when p1 is 2 and p2 is 3, according to the solution of the present embodiment, data items of the relationship diagram are stored in a memory, and each data item at least includes an observed rotor electrical angle position θ_e1Observing the electrical angular position theta of the rotor_e2And rotor absolute angular position observation theta_m。

Determination of observed rotor electrical angular position θ during operation of the electric machine by step S41_e1And observing the rotor electrical angular position theta_e2Thereafter, by querying the stored data, the rotor absolute angular position observation θ can be determined_m。

Step S43: observed value theta based on rotor absolute angle position_mAnd rotor absolute angular position reference valueObtaining the mechanical rotating speed reference value of the rotor

Reference value of rotor mechanical speedObtained through a position ring controller; the position loop controller is realized by a proportional controller, a proportional-integral controller or a proportional-integral-derivative controller.

Step S44: based on rotor mechanical speed referenceAnd observing the rotor electrical angular velocity omega_e1Generating a first switching signal S₁Based on a reference value of the mechanical rotational speed of the rotorAnd observing the rotor electrical angular velocity omega_e2Generating a second switching signal S₂。

In particular, the relationship ω between electrical angle and mechanical angle_e＝pω_mAs shown in fig. 5, in order to facilitate the parameter design of the speed loop controller, in this embodiment, the first pole pair number p1 and the mechanical rotor speed reference value are first determined according to the first pole pair number p1The product of which yields the reference value of the electrical angular velocity of the rotor of the first motor unitAccording to the second pole pair number p2 and the reference value of the rotor mechanical speedThe product of which yields the reference value of the electrical angular velocity of the rotor of the second motor unitThen the reference value of the rotor electrical angular velocity is obtainedAnd rotor electrical angular velocity reference valueFed into the speed loop controller 1 and the speed loop controller 2, respectively.

Of course, in other embodiments of the present invention, the rotor electrical angular velocity reference may not be calculatedAnd rotor electrical angular velocity reference valueTo reference the mechanical rotation speed of the rotorThe first and second pole pair numbers p1 and p2 may be fed directly into the speed ring controller 1 and 2, respectively, and then the calculation is performed in the speed ring controller.

Then, the speed loop controller 1 is used to calculate the reference value of the rotor electrical angular velocity of the first motor unitAnd observing the electrical angular velocity omega of the rotor_e1Obtaining a current loop reference value of the first motor unitReference value of the current loop of the first motor unitLine current i₁And observing the rotor electrical angular position theta_e1Obtaining a voltage reference value for the first motor unit via the current loop controller 1Voltage reference value of the first motor unitObtaining the first switching signal S after modulation₁。

By the speed loop controller 2 in dependence on the reference value of the electrical angular speed of the rotor of the second motor unitAnd observing the electrical angular velocity omega of the rotor_e2Obtaining a current loop reference value of the second motor unitCurrent loop reference value of the second motor unitLine current i₂And observing the rotor electrical angular position theta_e2Obtaining a voltage reference value of the second motor unit via the current loop controller 2Voltage reference value of the second motor unitModulating to obtain a second switching signal S₂。

The speed loop controller and the current loop controller are both realized by a proportional-integral controller or a proportional-integral-derivative controller.

The first switching signal S obtained according to the above steps₁And a second switching signal S₂Inputting a power circuit, wherein a double three-phase inverter circuit in the power circuit generates a first switching signal S₁And a second switchOff signal S₂Respectively drive the first motor unit and the second motor unit to operate under the control of the controller.

Specifically, referring to the structure diagrams of the dual three-phase inverter circuits shown in fig. 7 and 8, in the embodiment of the present invention, each group of switching signals (S) is provided₁Or S₂) Each contain 6 switching signals S_x1-S_x6Wherein x represents 1 or 2, 6 power switching devices VT for driving each set of three-phase inverter circuits_x1-VT_x6。

S_x1-S_x6The initial values are all 0, namely 6 switching devices are not conducted at the initial moment. In the working process, two switching devices (VT) of the same bridge arm_x1And VT_x2、VT_x3And VT_x4、VT_x5And VT_x6) Complementary conduction is carried out, certain dead zone time is arranged at intervals, and short circuit caused by direct connection of bridge arms is avoided.

S_x1-S_x6The generation method of (1) is preferably Space Vector Pulse Width Modulation (SVPWM), and other Modulation methods can be adopted on the premise of meeting the output voltage reference value.

In some embodiments of the present invention, the axial coaxial double-stator motor structure is adopted, and when the rotor axes of the first electrode unit and the second motor unit are not aligned, as shown in fig. 9, the absolute angular position deviation Δ θ between the two axes can be known in advance_mOr obtaining the absolute angle position deviation Delta theta of the two axes by initial position identification_mUsing the absolute angular position deviation Delta theta of the axis_mAnd carrying out constant compensation on the observed value of the absolute angle position of the rotor.

As can be seen from the effect diagram shown in fig. 10, when the method for sensorless control of absolute rotor position of a multi-pole motor proposed by the present invention is used, the observed value θ of the absolute rotor angular position is obtained_mCan well track the reference value of the absolute angle position of the rotor

The invention provides a multi-pole motor rotor absolute position sensorless control methodIn the motor, based on a double-stator motor structure, the pole pair numbers p1 and p2 of two motor units are limited to satisfy the conditions that the p1 is not equal to the p2, the greatest common divisor of the p1 and the p2 is 1, and | m × p1-n × p2| 1, the corresponding relation of the double-stator motor in one mechanical period is limited to be non-repetitive, and the rotor absolute angle position observed value theta can be calculated and obtained according to the non-repetitive corresponding relation_mAnd further, the observation value theta can be obtained from the absolute angular position of the rotor_mDeducing two-way switch signal S for controlling power circuit₁And S₂So that the power circuit adopts the two paths of switching signals S₁And S₂The method for driving the double-stator motor has the advantages of low cost, high integration degree, high reliability and the like, is beneficial to realizing more power integration in a limited space, and improves the power density of the motor.

It should be noted that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art should also make changes, modifications, additions or substitutions within the spirit and scope of the present invention.