KR102469648B1 - Control method for permanent magnet synchronous motor having double rotors structure - Google Patents

Abstract

The present invention relates to a control method for a permanent magnet synchronous motor having a double rotor structure, in which a stator is located at the outermost portion, an inner rotor is located at the innermost portion, an outer rotor having a pole piece is located between the stator and the inner rotor, and a permanent magnet ring is located between the stator and the outer rotor, thereby controlling the speed of a synchronous motor. The method of the present invention comprises: a step (a) of measuring the current speed of the inner rotor; a step (b) of estimating the current speed of the outer rotor; a step (c) of calculating a magnetic interference component caused by a torque generated from the stator with respect to the inner rotor and the outer rotor by using the measurement results of the step (a) and the step (b); and a step (d) of offsetting the magnetic interference component through conversion compensation according to a torque command of the stator. According to the present invention, even if the current speed of the inner rotor is measured with respect to the permanent magnet synchronous motor having the double rotor structure including the permanent magnet ring, the present invention can offset the magnetic interference component applied to the two rotors through conversion compensation by using the measurement value of the current speed, suppress resonance caused by a load variation in a railway vehicle to minimize speed and torque vibration in a transient state, simplify the control system configuration of the motor, and improve stability, durability, and ride comfort of the railway vehicle.

Description

Control method of permanent magnet synchronous motor having double rotor structure

The present invention controls a permanent magnet synchronous motor having a PDD (Pseudo Direct Drive) type dual rotor structure in which an outer rotor composed of pole pieces is positioned between the stator and the inner rotor and a permanent magnet ring is disposed inside the stator. A method for measuring the speed of an inner rotor using only one speed sensor and suppressing speed and torque vibration in a transient state using a result of estimating the speed of an outer rotor through sensorless logic It relates to a control method of a permanent magnet synchronous motor having a double rotor structure.

In general, a driving system for a railway vehicle uses a permanent magnet synchronous motor as a power source. Conventionally, a permanent magnet synchronous motor having a single rotor structure has been used, but recently, attempts to apply a permanent magnet synchronous motor having a double rotor structure have been increasing in order to increase power transmission efficiency.

A permanent magnet synchronous motor with a dual rotor structure in which a magnetic gear and PMSM (Permanent Magnet Synchronous Motor) are combined has high torque output while occupying a smaller space than conventional permanent magnets.

1 is an exploded perspective view illustrating a permanent magnet synchronous motor of a conventional dual rotor structure. Referring to FIG. 1 , in the dual rotor permanent magnet synchronous motor, the stator 100 is positioned at the outermost part and the inner rotor 300 including the permanent magnet 310 is positioned at the innermost part. A coil 120 is wound around the slot 110 provided in the stator 100 . An outer rotor 200 composed of pole pieces is positioned between the stator 100 and the inner rotor 300.

In the illustrated double rotor permanent magnet motor, the number of pole pairs of the inner rotor 300 and the outer rotor 200 should be designed to generate the magnetic flux modulation effect. Nevertheless, as the torque generated in the stator 100 is simultaneously transmitted in parallel according to the pole number ratio of each rotor, when controlling the speed of the motor, the change in the speed of one rotor due to the change in the load torque is different from the other rotor. will affect That is, the speed control of the permanent magnet synchronous motor of the conventional dual rotor structure means the relative speed control of the inner rotor 300 and the outer rotor 200. Due to this, there is a problem in that speed and torque vibrations occur in a transient state when controlling the motor.

Korean Patent Publication No. 10-2021-0059235 Korean Patent Publication No. 10-2006-0022376

The present invention relates to a method for stably controlling a permanent magnet synchronous motor having a dual rotor structure including a permanent magnet ring, and magnetic interference components inevitably generated while torque of a stator is transmitted to an inner rotor and an outer rotor. Provides a control method of a permanent magnet synchronous motor with a dual rotor structure that minimizes speed and torque vibration in a transient state by suppressing a phenomenon in which resonance occurs due to a load change in a railway vehicle by offsetting with forward compensation. has its purpose.

In the control method of a permanent magnet synchronous motor having a dual rotor structure according to an embodiment of the present invention, a stator is located on the outermost side, an inner rotor is located on the innermost side, and a magnetic pole is located between the stator and the inner rotor. In the control method of a permanent magnet synchronous motor having a double rotor structure for controlling the speed of a synchronous motor in which an outer rotor composed of one piece is positioned and a permanent magnet ring is positioned between the stator and the outer rotor, (a) ) measuring the current speed of the inner rotor; (b) estimating the current speed of the outer rotor; (c) calculating a magnetic interference component generated by torque generated in the stator with respect to the inner rotor and the outer rotor using the measurement results of steps (a) and (b); and (d) forward-compensating and canceling the magnetic interference component in response to the torque command of the stator.

In the method for controlling a permanent magnet synchronous motor having a dual rotor structure according to another embodiment of the present invention, in the step (c), the magnetic interference component is calculated through Equation 11 below.

[Equation 11]

은 상기 자기적 간섭성분이고,

은 상기 내측 회전자의 극쌍수이고,

은 상기 외측 회전자의 극쌍수이고,

는 상기 내측 회전자에서 상기 외측 회전자로 전달할 수 있는 최대 토크이고,

는 상기 내측 회전자와 상기 외측 회전자의 전기각 차이이다.here

is the magnetic interference component,

is the number of pole pairs of the inner rotor,

is the number of pole pairs of the outer rotor,

Is the maximum torque that can be transmitted from the inner rotor to the outer rotor,

Is the difference in electrical angle between the inner rotor and the outer rotor.

In the control method of a permanent magnet synchronous motor having a dual rotor structure according to another embodiment of the present invention, the step (d) is, (d-1) of the inner rotor from the speed command for the inner rotor subtracting the current speed; (d-2) generating a torque command for the stator by proportionally integrating the result of step (c-1); and (d-3) forward-compensating the torque command of the stator by subtracting the magnetic interference component from the torque command of the stator.

In the control method of a permanent magnet synchronous motor having a dual rotor structure according to another embodiment of the present invention, the step (b) estimates the current speed of the outer rotor through sensorless logic.

In the control method of a permanent magnet synchronous motor having a dual rotor structure according to another embodiment of the present invention, the step (b) is performed by applying an estimated current to a coil wound around the stator in step (b-1) to perform the synchronous operation. Forcibly starting the motor; (b-2) estimating the combined electromotive force of each phase of the coil; and (b-3) estimating a position error of the outer rotor using the combined electromotive force; and (b-4) estimating the speed of the outer rotor based on the position error.

According to the control method of a permanent magnet synchronous motor having a dual rotor structure of the present invention, even if only the current speed of the inner rotor is measured for the permanent magnet synchronous motor with a dual rotor structure including a permanent magnet ring, the measured value is used. Thus, the magnetic interference component applied to the two rotors can be offset by forward compensation, and the phenomenon of resonance caused by the load change in the railway vehicle can be suppressed to minimize the speed and torque vibration in the transient state. It is possible to simplify the configuration of the control system, and there is an effect of improving the stability, durability and riding comfort of the railway vehicle.

1 is an exploded perspective view illustrating a permanent magnet synchronous motor of a conventional dual rotor structure;
2 is a cross-sectional view illustrating a permanent magnet synchronous motor having a PDD type double rotor structure;
3 is a block diagram mechanically modeling the synchronous motor of FIG. 2 by applying a magnetic spring;
4 is a block diagram modeling a control process of a permanent magnet synchronous motor having a dual rotor structure according to the present invention using the modeling of FIG. 3 and Equation 1;
5 is a speed controller block diagram before applying forward compensation according to the present invention;
6 is a speed controller block diagram after applying forward compensation according to the present invention;
7 is a block diagram simplifying the model of FIG. 4 according to the speed control method of FIG. 6;
8 is a waveform diagram showing simulation analysis results before applying forward compensation according to the present invention; and
9 is a waveform diagram showing simulation analysis results after applying forward compensation according to the present invention.

Hereinafter, specific embodiments according to the present invention will be described with reference to the accompanying drawings. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Parts having similar configurations and operations are given the same reference numerals throughout the specification. In addition, the drawings accompanying the present invention are for convenience of description, and the shape and relative scale may be exaggerated or omitted.

In describing the embodiments in detail, redundant descriptions or descriptions of obvious technologies in the art are omitted. In addition, when a certain part "includes" another component in the following description, this means that it may further include components other than the described components unless otherwise stated.

In addition, terms such as "~ unit", "~ group", and "~ module" described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. can In addition, when a part is said to be electrically connected to another part, this includes not only the case where it is directly connected but also the case where it is connected with another component interposed therebetween.

Terms including ordinal numbers, such as first and second, may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a second element may be termed a first element, and similarly, a first element may be termed a second element, without departing from the scope of the present invention.

The control method of a permanent magnet synchronous motor having a double rotor structure of the present invention is a magnetic coupling type 2 double rotor permanent magnet synchronous motor (DR-PMSM, Dual-Rotor Permanent Magnet Synchronous Motor), for example PDD (Pseudo Direct Drive) type DR-PMSM. Prior to a detailed description of the present invention, a DR-PMSM structure of a PDD type will be briefly described with reference to FIG. 2 .

2 is a cross-sectional view illustrating a permanent magnet synchronous motor having a PDD type dual rotor structure. Referring to FIG. 2 , in the DR-PMSM to be controlled, the stator 100 is located on the outermost side and the inner rotor 300 including the permanent magnet 310 is located on the innermost side. A coil 120 is wound around the slot 110 provided in the stator 100 . An outer rotor 200 composed of pole pieces is positioned between the stator 100 and the inner rotor 300. Up to this point, it is the same as DR-PMSM of magnetic coupling type 1. The difference is that the permanent magnet ring 210 is positioned between the stator 100 and the outer rotor 200 .

The magnetic coupling type 2 synchronous motor illustrated in FIG. 2 is designed with the same number of pole pairs of the stator 100 and the number of pole pairs of the inner rotor 300, so that the rotating magnetic field generated from the stator 100 and the inner rotor ( 300) may rotate synchronously. At this time, the magnetic flux of the inner rotor 300 is modulated through the pole piece. The modulated magnetic flux interacts with the permanent magnet ring 210 for harmonic components that can be synchronized. The permanent magnet ring 210 is fixed, and when the inner rotor 300 rotates, the outer rotor 200 rotates to synchronize harmonics of the modulated magnetic flux.

The magnetic coupling type 2 synchronous motor has a better power factor than the magnetic coupling type 1 synchronous motor exemplified in the background art by the permanent magnet ring 210, and has higher efficiency and output than modulation devices using the magnetic flux modulation effect. There are high advantages.

FIG. 3 is a block diagram mechanically modeling the synchronous motor of FIG. 2 by applying a magnetic spring. Referring to FIG. 3 , the rotation principle of the DR-PMSM to which the permanent magnet ring 210 is added can be expressed as a torque transmission model between the inner rotor 300 and the outer rotor 200 to which a magnetic spring is added. Reference numeral 400 is a load connected to the synchronous motor.

[Equation 1]

[Equation 2]

은 외측 회전자의 토크이고,

는 내측 회전자에서 외측 회전자로 전달할 수 있는 최대 토크이고,

는 내측 회전자와 외측 회전자의 전기각 차이이고,

은 내측 회전자의 극쌍수이고,

은 내측 회전자의 속도이고,

은 외측 회전자의 극쌍수이고,

은 외측 회전자의 속도이다.Equation 1 represents the torque transfer characteristics of the magnetic spring, and Equation 2 represents the electrical angle difference in Equation 1. here,

is the torque of the outer rotor,

is the maximum torque that can be transmitted from the inner rotor to the outer rotor,

is the electrical angle difference between the inner and outer rotors,

is the number of pole pairs of the inner rotor,

is the speed of the inner rotor,

is the number of pole pairs of the outer rotor,

is the speed of the outer rotor.

It can be seen from Equations 1 and 2 that the torque transfer characteristics of the magnetic spring are determined by the difference in electric angle between the inner rotor and the outer rotor.

4 is a block diagram modeling a control process of a permanent magnet synchronous motor having a dual rotor structure according to the present invention using the modeling of FIG. 3 and Equation 1.

)에 제어 상수(

, 410)를 승산하여 고정자(100)에 대한 토크 지령(

)이 출력된다. 감산부(420)는 토크 지령(

)에서 후술하는 자기적 간섭성분(

)을 감산하며, 내측 회전자 전달요소(430)를 통해 내측 회전자의 속도(

)가 결정된다. 내측 회전자 전달요소(430)의 전달함수는 관성모멘트(

)를 미분한 값과 마찰계수(

)의 합의 역수로 나타낼 수 있다.Referring to FIG. 4, the current command (

) to the control constant (

, 410) to obtain a torque command for the stator 100 (

) is output. The subtraction unit 420 provides a torque command (

), the magnetic interference component described later (

) is subtracted, and the speed of the inner rotor through the inner rotor transmission element 430 (

) is determined. The transfer function of the inner rotor transmission element 430 is the moment of inertia (

) and the friction coefficient (

) can be expressed as the reciprocal of the sum of

)에 내측 회전자의 극쌍수(

, 440)를 승산한 값에서 외측 회전자의 속도(

)에 외측 회전자의 극쌍수(

, 500)를 승산한 값을 감산한다. 이 감산 결과에 토크 상수 전달요소(460)의 전달함수를 승산한 경과 외측 회전자의 토크 지령(

)이 출력된다. 토크 상수 전달요소(460)에서

는 마그네틱 스프링으로 표현되는 회전자간 토크 전달 제어 상수를 나타내며,

는 라플라스 연산자를 나타낸다. 외측 회전자의 토크 지령(

)에 내측 회전자와 외측 회전자의 극쌍수 비(

, 470)를 승산한 값이 피드백 제어의 오차 연산을 위해 제공된다.The subtraction unit 450 is the speed of the inner rotor (

) to the number of pole pairs of the inner rotor (

, 440), the speed of the outer rotor (

) to the number of pole pairs of the outer rotor (

, 500) is subtracted. The torque command of the outer rotor after multiplying the result of this subtraction by the transfer function of the torque constant transmission element 460 (

) is output. In the torque constant transmission element 460

Represents the torque transfer control constant between the rotors expressed as a magnetic spring,

represents the Laplace operator. External rotor torque command (

) to the pole pair ratio of the inner and outer rotors (

, 470) is provided for error calculation of feedback control.

)에서 부하 토크(

)를 감산하고, 그 결과가 외측 회전자 전달요소(490)를 통해 출력되어 외측 회전자의 속도(

)가 결정된다. 외측 회전자 전달요소(490)의 전달함수는 관성모멘트(

)를 미분한 값과 마찰계수(

)의 합의 역수로 나타낼 수 있다.The subtraction unit 480 is the torque command of the outer rotor (

) at the load torque (

) is subtracted, and the result is output through the outer rotor transmission element 490, and the speed of the outer rotor (

) is determined. The transfer function of the outer rotor transmission element 490 is the moment of inertia (

) and the friction coefficient (

) can be expressed as the reciprocal of the sum of

)를 지령으로 하여 내측 회전자(300)가 회전될 때, 도 3의 모델에서 마그네틱 스프링이 비틀어지면서 외측 회전자(200)로 토크가 전달된다. 이와 동시에 마그네틱 스프링의 비틀림 토크가 내측 회전자(300)에도 되돌아오는 자기적 간섭성분이 발생한다.At this time, the stator torque (

) as a command, when the inner rotor 300 is rotated, torque is transmitted to the outer rotor 200 while the magnetic spring is twisted in the model of FIG. 3 . At the same time, a magnetic interference component in which the torsional torque of the magnetic spring returns to the inner rotor 300 is generated.

As shown, when modeling the torque transmission process between the inner rotor 300 and the outer rotor 200 using a magnetic spring, a resonance point is generated by the nonlinear Sin component and magnetic interference component of the magnetic spring. do. The resonance point can be confirmed through the transfer function of the modeling illustrated in FIG. 4 .

[Equation 3]

[Equation 4]

에 대한 각 회전자 속도의 전달함수로 나타내면 다음의 수학식 5 및 6으로 나타낼 수 있다.Equations 3 and 4 represent transfer functions of the inner rotor speed and the outer rotor speed with respect to the stator torque and the load torque, respectively. Using the principle of superposition of the above two equations,

When expressed as a transfer function of each rotor speed for , it can be expressed by Equations 5 and 6 below.

[Equation 5]

[Equation 6]

That is, there is a zero in Equation 5, which is the transfer function of the inner rotor speed for the torque generated by the stator, and there is no zero in Equation 6, which is the transfer function of the outer rotor speed. . Here, zero represents an anti-resonance point, which means that there is a frequency band in which the inner rotor cannot rotate. This is a factor that degrades driving characteristics, and when selecting a controller bandwidth, it is necessary to design avoiding the corresponding area.

The poles of Equations 5 and 6 mean resonance frequencies, and it can be confirmed that the resonance frequencies generated on the inside and outside are the same. When the anti-resonant frequency and the resonance frequency are expressed as equations through the zeros and poles of Equations 5 and 6, they can be expressed as Equations 7 and 8 below.

[Equation 7]

[Equation 8]

는 상기한 반공진 주파수이고,

은 상기한 공진 주파수이다. 수학식 7과 8을 통해 반공진 주파수와 공진 주파수는

와 각 회전자의 관성모멘트에 영향을 받는 것을 알 수 있다. 특히 부하의 영향으로 외측 회전자의 관성모멘트가 증가할 경우 공진 주파수는 낮은 주파수로 이동할 것임을 알 수 있다.here,

is the anti-resonance frequency described above,

is the above resonant frequency. Through Equations 7 and 8, the anti-resonant frequency and the resonant frequency are

and the moment of inertia of each rotor. In particular, it can be seen that when the moment of inertia of the outer rotor increases due to the influence of the load, the resonant frequency will move to a lower frequency.

의 전달함수를 구한 것과 같이 중첩의 원리를 이용하여 부하토크

에 대한 각 회전자 속도의 전달함수를 도출할 수 있다. 도출된 전달함수는 수학식 9와 10으로 나타낼 수 있다.In Equations 3 and 4

Load torque using the principle of superposition as in the transfer function of

The transfer function of each rotor speed for can be derived. The derived transfer function can be expressed by Equations 9 and 10.

[Equation 9]

[Equation 10]

와 마찬가지로 부하 토크(

)의 변동으로 각 회전자에 공진이 발생하는 것을 알 수 있다. 철도차량에서 부하변동으로 공진이 발생할 경우 차량에 떨림이 발생하고 철도차량의 안정성, 내구성 및 승차감에 문제를 발생하므로 반드시 해결되어야 하는 문제이다.Through Equations 9 and 10

As with the load torque (

), it can be seen that resonance occurs in each rotor. When resonance occurs due to load variation in a railway vehicle, vibration occurs in the vehicle and problems arise in the stability, durability, and ride quality of the railway vehicle, so it is a problem that must be solved.

)가 감산부(480), 외측 회전자 전달요소(490), 감산부(450), 토크 상수 전달요소(460), 감산부(420)를 거쳐 내측 회전자 전달요소(430)에 이르는 것을 확인할 수 있다. 즉, 부하 토크의 변화가 내측 회전자에 영향을 미치므로, 마그네틱 스프링에 의해 발생한 공진이 상단의 폐루프를 통해 내측 회전자(300)에 간섭을 준다. 이러한 자기적 간섭성분은 고정자(100)의 토크가 내측 회전자를 제어하는데 방해 요소가 되므로 상쇄시킬 필요가 있다.In the present invention, forward torque compensation control is performed to reduce the resonance phenomenon. Referring to FIG. 4, the load torque (

) reaches the inner rotor transmission element 430 via the subtraction unit 480, the outer rotor transmission element 490, the subtraction unit 450, the torque constant transmission element 460, and the subtraction unit 420. can That is, since the change in load torque affects the inner rotor, the resonance generated by the magnetic spring interferes with the inner rotor 300 through the closed loop at the upper end. These magnetic interference components need to be offset because the torque of the stator 100 becomes an obstacle in controlling the inner rotor.

[Equation 11]

,

,

는 전동기의 파라미터이며 운전중 변하지 않는다고 가정한다.

는 수학식 2에서와 같이 내측 회전자와 외측 회전자의 속도에 의해 결정된다. 따라서 내측 회전자와 외측 회전자의 속도를 알 수 있다면 자기적 간섭성분을 계산할 수 있다.The magnetic interference component can be calculated through Equation 11. here

,

,

is a parameter of the motor and is assumed not to change during operation.

Is determined by the speed of the inner rotor and the outer rotor as in Equation 2. Therefore, if the speeds of the inner and outer rotors are known, the magnetic interference component can be calculated.

5 is a speed controller block diagram without considering the magnetic interference component of Equation 11, that is, before forward compensation is applied. 6 is a block diagram of a speed controller after considering a magnetic interference component, that is, after applying forward compensation.

)에서 내측 회전자의 현재 속도(

)를 감산하여 오차를 연산한다. 속도 제어기(520)는 오차 검출 결과를 비례적분하여 고정자의 토크 지령(

)을 생성한다. 이와 같은 일반적인 속도 제어를 실시할 경우 도 4에 도시된 바와 같이 자기적 간섭성분이 내측 회전자의 제어에 영향을 미치게 되며, 후술하는 모의해석 결과에서와 같이 부하 변동 시에 속도의 오버슈트나 진동이 발생될 수 있다.Referring to FIG. 5, the first subtractor 510 provides a speed command for the inner rotor (

) at the current speed of the inner rotor (

) to calculate the error. The speed controller 520 proportionally integrates the error detection result to obtain the stator torque command (

) to create When such a general speed control is performed, the magnetic interference component affects the control of the inner rotor as shown in FIG. this may occur.

)에서 수학식 11을 통해 연산된 자기적 간섭성분(

)을 감산하여 토크 지령을 전향 보상하고 있다. 여기서, 내측 회전자의 속도는 센서를 통해서 측정하고, 외측 회전자의 속도는 센서리스 로직을 통해 추정한 후, 두 회전자의 전기각 차이로부터 자기적 간섭성분(

)을 연산하고, 이를 속도 제어기(520)의 출력측에 보상함으로써, 자기적 간섭성분을 상쇄될 수 있게 된다. 외측 회전자의 속도를 추정하는 것은 통상 알려진 다양한 센서리스 로직을 통해 달성될 수 있다.Referring to FIG. 6 , compared to FIG. 5 , the second subtractor 530 provides a torque command of the stator (

), the magnetic interference component calculated through Equation 11 (

) is subtracted to forward-compensate the torque command. Here, the speed of the inner rotor is measured through a sensor, and the speed of the outer rotor is estimated through sensorless logic, and then the magnetic interference component (from the difference in electrical angle between the two rotors)

), and by compensating for it on the output side of the speed controller 520, the magnetic interference component can be canceled. Estimating the speed of the outer rotor can be accomplished through various commonly known sensorless logic.

For example, a synchronous motor is forcibly started by applying an estimated current to a coil wound around a stator. Then, the combined electromotive force of each phase of the coil is estimated. The position error of the initial position of the outer rotor can be estimated from the estimation result of the combined electromotive force. Finally, the speed of the outer rotor is estimated based on the position error.

)와 내측 회전자 속도(

)의 전달함수는 1차식으로 나타낼 수 있으며, 1차 선형제어기인 PI 제어기를 이용하여 쉽게 제어할 수 있게 된다.FIG. 7 is a simplified block diagram of the control model of FIG. 4 according to the speed control method of FIG. 6 . That is, modeling of the dual rotor permanent magnet synchronous motor can be simplified by removing the upper loop in the modeling of the dual rotor permanent magnet synchronous motor as shown in FIG. 7 according to forward compensation as shown in FIG. 6 . If the magnetic interference component is omitted, the stator torque (

) and the inner rotor speed (

) can be expressed as a first-order equation, and can be easily controlled using a PI controller, which is a first-order linear controller.

8 is a waveform diagram showing simulation analysis results before applying forward compensation as shown in FIG. 5, and FIG. 9 is a waveform diagram showing simulation analysis results after applying forward compensation as shown in FIG. In both simulation analyses, DR-PMSM of the same 1kw class magnetic coupling type 2 was targeted, and each parameter of the motor was applied as shown in Table 1 below.

[Table 1]

The switching frequency was selected as 8 kHz, and the bandwidth of the current controller was selected as 320 kHz, which is 1/25 of the switching frequency.

Referring to FIG. 8 , it was confirmed that the speed of the outer rotor was maintained for 1-2 seconds at 0 seconds, 2 seconds, and 5 seconds when the load fluctuated. On the other hand, referring to FIG. 9 , when forward compensation is performed, it can be seen that the overshoot of the outer rotor speed is greatly reduced and the vibration also quickly disappears even when the load changes under the same conditions.

The invention disclosed above is capable of various modifications within a range that does not impair the basic idea. That is, all of the above embodiments should be interpreted as illustrative and not limited. Therefore, the protection scope of the present invention should be determined according to the appended claims, not the above-described embodiments, and when the elements defined in the appended claims are replaced with equivalents, it should be regarded as belonging to the protection scope of the present invention.

100: stator 110: slot
120: coil 200: outer rotor
210: permanent magnet ring 300: inner rotor
310: permanent magnet 400: load
510: first subtractor 520: speed controller
530: second subtractor

Claims (5)

A stator is located on the outermost side, an inner rotor is located on the innermost side, an outer rotor composed of pole pieces is located between the stator and the inner rotor, and a permanent magnet ring is positioned between the stator and the outer rotor. In the control method of a permanent magnet synchronous motor having a double rotor structure for controlling the speed of a synchronous motor located,
(a) measuring the current speed of the inner rotor;
(b) estimating the current speed of the outer rotor;
(c) Calculate the magnetic interference component generated by the torque generated in the stator with respect to the inner rotor and the outer rotor using the measurement results of steps (a) and (b) and Equation 11 below. doing; and
(d) forward-compensating and canceling the magnetic interference component in response to the torque command of the stator
Control method of a permanent magnet synchronous motor having a double rotor structure comprising a.
[Equation 11]

here

is the magnetic interference component,

is the number of pole pairs of the inner rotor,

is the number of pole pairs of the outer rotor,

Is the maximum torque that can be transmitted from the inner rotor to the outer rotor,

Is the difference in electrical angle between the inner rotor and the outer rotor.
delete According to claim 1,
In the step (d),
(d-1) subtracting the current speed of the inner rotor from the speed command for the inner rotor;
(d-2) generating a torque command for the stator by proportionally integrating the result of step (c-1); and
(d-3) forward-compensating the torque command of the stator by subtracting the magnetic interference component from the torque command of the stator
Control method of a permanent magnet synchronous motor having a double rotor structure comprising a.
According to claim 1 or 3,
The step (b) is a control method of a permanent magnet synchronous motor having a dual rotor structure for estimating the current speed of the outer rotor through sensorless logic.
According to claim 4,
In the step (b),
(b-1) forcibly starting the synchronous motor by applying an estimated current to a coil wound around the stator;
(b-2) estimating the combined electromotive force of each phase of the coil; and
(b-3) estimating a position error of the outer rotor using the combined electromotive force; and
(b-4) estimating the speed of the outer rotor based on the position error
Control method of a permanent magnet synchronous motor having a double rotor structure comprising a.

Images