KR102461128B1 - Sensorless control apparatus and method of permanent magnet synchronous motor - Google Patents

Abstract

Disclosed are a sensorless control device and a control method for a permanent magnet motor. A sensorless control apparatus for a permanent magnet motor according to an embodiment of the present invention includes: a first estimator for estimating first physical quantity information describing an operation of the motor in a stationary coordinate system; a second estimator for estimating second physical quantity information representing the counter electromotive force of the electric motor in a synchronous coordinate system based on a first estimated value for an angle of a rotor of the electric motor obtained based on the first physical quantity information; and a position/speed detector for generating position and speed information of a rotor of the electric motor in which an error included in the angle of the first estimated value is compensated by using the second physical quantity information.

Description

Sensorless control device and control method of permanent magnet motor {SENSORLESS CONTROL APPARATUS AND METHOD OF PERMANENT MAGNET SYNCHRONOUS MOTOR}

The present invention relates to a sensorless control apparatus and method for a permanent magnet synchronous motor (PMSM). Specifically, sensorless control is a technology for estimating information necessary to control a motor from the voltage and current supplied to the motor without using a physical sensor in the permanent magnet motor, and controlling the permanent magnet motor based on the estimated information. is about

BACKGROUND ART An electric motor is a device that converts electrical energy into mechanical energy by using the force received by a conductor through which an electric current flows in a magnetic field. Motors are classified into DC motors and AC motors according to the type of power source. AC motors are divided into single-phase AC motors and three-phase AC motors, and there are induction motors and synchronous motors respectively.

Since a synchronous motor receives magnetic flux from a permanent magnet attached to the rotor, it is necessary to know the position information of the rotor for vector control. In order to obtain the position information of the rotor, a position detection sensor such as a Hall sensor, a resolver, or an encoder must be attached to the shaft of the motor. However, the position detection sensor has disadvantages in that it is expensive and requires separate and complicated hardware. In addition, there is a problem in that the size of the motor and the inertia of the motor increase due to the attachment of the position detection sensor to the shaft of the motor.

In addition, the position detection sensor used at this time has an absolutely disadvantageous problem in an environment where electric motors are widely used, for example, vibration resistance, shock resistance, corrosion resistance, temperature resistance and moisture resistance are required except for special cases.

Accordingly, research on a sensorless control method capable of controlling an electric motor without a position sensor is being actively conducted.

In general, the sensorless control algorithm of a permanent magnet synchronous motor (PMSM) is classified into a harmonic injection method (signal injection method) and a model-based method. The harmonic injection method shows excellent performance in the range from stop to low speed and low torque, but is not suitable for high-speed motor control. The model-based method is advantageous for high-speed control by performing sensorless control based on a mathematical model. On the other hand, the model-based method has the disadvantage that the system may become unstable due to parameter fluctuations during low-speed operation and rapid acceleration, so it is known that responses such as improvement of responsiveness are necessary.

One of the model-based sensorless control algorithms is a sensorless control method based on back EMF estimation. This method estimates the back electromotive force (EMF) using an electric or electromechanical model of the motor and acquires speed and rotor position information. The back EMF estimation sensorless control method is divided into a method based on a stationary coordinate system and a method based on a synchronous coordinate system. For example, in Korean Patent Publication No. KR 10-1329132 "Sensorless control device of a permanent magnet motor" and Korean Patent Publication KR 10-2020-0046692 "Sensorless control method of an electric motor", a sensorless control method based on synchronous coordinate system counter electromotive force estimation An improved version of the is introduced.

Another prior literature, "Evaluation of Back-EMF Estimators for Sensorless Control of Permanent Magnet Synchronous Motors", Lee, Kwang-Woon and Ha, Jung-Ik, Journal of Power Electronics, vol. 12, no. 4, pp. 604-614, Jul. 2012. introduces and compares the sensorless control methods of the stationary coordinate system-based back EMF estimation and the synchronous coordinate system-based back EMF estimation.

Another prior literature, "Active flux concept for motion-sensorless unified AC drives", I. Boldea, M. C. Paicu, and G. D. Andreescu, IEEE Trans. Power Electron., vol. 23, no. 5, pp. 2612-2618, Sep. In 2008, problems and improvements of a sensorless control method based on magnetic flux estimation are disclosed, and the disclosed magnetic flux estimation is performed in a stationary coordinate system.

PMSM sensorless control methods based on counter electromotive force or magnetic flux estimation can be considered to have their characteristics determined according to the coordinate system in which the voltage equation corresponding to the mathematical model of the motor is expressed. Since the conventional model-based PMSM sensorless control methods are based on one of the above-mentioned three mathematical models, it is difficult to implement stable sensorless control performance in a wide operation range ranging from low-speed and high-speed operation areas.

Another prior document, Korean Patent Publication No. KR 10-1961106 "Sensorless Control Method and Apparatus," proposes a hybrid sensorless control method as a method of detecting whether a step-out occurs in sensorless control, rather than precise sensorless control. In this prior document, a sensorless control method based on synchronous coordinate system counter electromotive force estimation is adopted, but a stationary coordinate system-based magnetic flux estimation method is applied in parallel to detect a step-out.

However, even with reference to the preceding documents, the advantages and disadvantages of each of the conventional model-based PMSM sensorless control methods are clearly distinguished, and it is difficult to implement stable sensorless control performance in a wide operating range simply by combining them. .

Korean Patent Publication KR 10-1329132 "Sensorless control device of permanent magnet motor" (November 7, 2013) Korean Patent Application Laid-Open No. KR 10-2020-0046692 "Method for sensorless control of electric motor" (May 7, 2020) Korean Patent Publication No. KR 10-1961106 "Sensorless control method and apparatus" (March 18, 2019)

"Evaluation of Back-EMF Estimators for Sensorless Control of Permanent Magnet Synchronous Motors", Lee, Kwang-Woon and Ha, Jung-Ik, Journal of Power Electronics, vol. 12, no. 4, pp. 604-614, Jul. 2012. (July 1, 2012) "Active flux concept for motion-sensorless unified AC drives", I. Boldea, M. C. Paicu, and G. D. Andreescu, IEEE Trans. Power Electron., vol. 23, no. 5, pp. 2612-2618, Sep. 2008 (September 1, 2008)

An object of the present invention relates to a model-based sensorless control apparatus and method for estimating the position and speed of a rotor of a PMSM from the voltage and current supplied to an electric motor without using a separate sensor. To present an apparatus and method for estimating rotor position/speed that can improve the performance of model-based sensorless control.

)에 포함되는 오차가 PLL의 적분기에 누적되어 센서리스 제어 성능이 저하되는 현상)을 상호 보완적으로 해결할 수 있는 장점이 있다. 따라서 넓은 운전 영역에 걸쳐서 PMSM의 모델 기반 센서리스 제어 방식의 안정적인 성능을 확보할 수 있다.SUMMARY OF THE INVENTION It is an object of the present invention to provide a sensorless control apparatus and method for PMSM that can secure stable sensorless control performance in a wide operation area including low-speed and high-speed operation areas. The first embodiment presented in the present invention is a hybrid method combining a magnetic flux estimation method using a stationary coordinate system voltage equation and a counter electromotive force estimation method using a synchronous coordinate system voltage equation. A phenomenon in which sensorless control performance deteriorates due to an increase in the error of the sensorless position estimation value due to phase lead in the region) and a problem in the method of estimating the back EMF from the synchronous coordinate system voltage equation (position due to nonlinearity of inverter and parameter fluctuation of PMSM) Estimated value for error (

) has the advantage of complementarily solving the phenomenon that the sensorless control performance deteriorates due to the accumulation of errors in the integrator of the PLL. Therefore, it is possible to secure the stable performance of the model-based sensorless control method of PMSM over a wide operating area.

The second embodiment presented in the present invention is a hybrid method combining a back EMF estimation method using a stationary coordinate system voltage equation and a back EMF estimation method using a synchronous coordinate system voltage equation. The disadvantages of the back EMF estimation method using the voltage equation can be complementarily solved.

It is an object of the present invention to complementarily combine model-based sensorless control methods based on a mathematical model having different main operation areas, but do not simply combine them in parallel with each other, but sequentially to complement each other's shortcomings. It is to propose a new sensorless control method that combines It is an object of the present invention to propose a plurality of embodiments for implementing stable sensorless control performance in a wide driving range by complementarily combining model-based sensorless control methods having different main driving ranges.

The present invention is a configuration derived to achieve the above object, and the sensorless control apparatus for a permanent magnet motor according to an embodiment of the present invention is a first physical quantity information for estimating the first physical quantity information describing the operation of the motor in a stationary coordinate system. 1 estimator; a second estimator for estimating second physical quantity information representing the counter electromotive force of the electric motor in a synchronous coordinate system based on a first estimated value for an angle of a rotor of the electric motor obtained based on the first physical quantity information; and a position/speed detector for generating position and speed information of a rotor of the electric motor in which an error included in the angle of the first estimated value is compensated by using the second physical quantity information. In this case, the synchronization coordinate system of the second estimator may be understood as a synchronization coordinate system based on the angle of the first physical quantity information. Also, it may be understood that the position/velocity detector generates position and velocity information of a rotor in which an error included in the angle of the first physical quantity information is compensated.

The first physical quantity information may be a magnetic flux of the electric motor.

The first physical quantity information may be a counter electromotive force of the electric motor.

When the first physical quantity information is the magnetic flux of the electric motor, the first estimator may include: a magnetic flux estimator for estimating the magnetic flux of the electric motor in the stationary coordinate system as the first physical quantity information; and a magnetic flux angle calculator generating the first estimated value for the angle of the rotor of the electric motor based on the first physical quantity information.

When the first physical quantity information is the back electromotive force of the motor, the first estimator may include: a first counter electromotive force estimator for estimating the back electromotive force of the motor in the stationary coordinate system as the first physical quantity information; and a counter electromotive force angle calculator generating the first estimated value for the angle of the rotor of the electric motor based on the first physical quantity information.

The second estimator may include: a second back EMF estimator for estimating the second physical quantity information representing the back EMF of the electric motor in a synchronous coordinate system based on the first estimated value; an angular velocity calculator for calculating the angular velocity of the rotor of the electric motor based on the first physical quantity information and transmitting the angular velocity to the second counter electromotive force estimator; and an angle error calculator configured to calculate an error included in the angle of the first estimated value based on the angular velocity and the second physical quantity information.

The second estimator may further include an axis converter that converts the voltage and current values of the electric motor in the stationary coordinate system into voltage and current values of the electric motor in the synchronous coordinate system and transmits the converted voltage and current values to the second counter electromotive force estimator.

The axis converter sets an estimated synchronous coordinate system based on the estimated D-axis with respect to the actual D-axis of the rotor of the motor, and uses the estimated synchronous coordinate system as the synchronous coordinate system for converting voltage and current values of the motor. can In this case, the shaft converter may set the estimated synchronization coordinate system based on the first estimated value for the angle of the rotor of the electric motor obtained from the first physical quantity information.

The sensorless control method of an electric motor according to an embodiment of the present invention is a model-based sensorless control method using voltage and current supplied to a permanent magnet motor (PMSM). The sensorless control method of the present invention includes a first estimation step of estimating first physical quantity information describing the operation of the electric motor in a stationary coordinate system; a second estimation step of estimating second physical quantity information representing the counter electromotive force of the electric motor in a synchronous coordinate system based on a first estimated value for an angle of a rotor of the electric motor obtained based on the first physical quantity information; and a position/speed detection step of generating position and speed information of a rotor of the electric motor in which an error included in the angle of the first estimated value is compensated by using the second physical quantity information.

The first estimating step may include: a magnetic flux estimating step of estimating the magnetic flux of the electric motor as the first physical quantity information in the stationary coordinate system; and a magnetic flux angle calculation step of generating the first estimated value for the angle of the rotor of the electric motor based on the first physical quantity information.

The first estimating step may include: a first back EMF estimating step of estimating the back EMF of the electric motor as the first physical quantity information in the stationary coordinate system; and a counter electromotive force angle calculation step of generating the first estimated value for the angle of the rotor of the electric motor based on the first physical quantity information.

The second estimating step may include: a second back EMF estimating step of estimating the second physical quantity information representing the back EMF of the electric motor in a synchronous coordinate system based on the first estimated value; an angular velocity calculation step of calculating an angular velocity of a rotor of the electric motor based on the first physical quantity information and transferring the angular velocity to the second counter electromotive force estimating step; and calculating an error included in the angle of the first estimated value based on the angular velocity and the second physical quantity information.

The second estimating step may further include converting the voltage and current values of the motor in the stationary coordinate system into the voltage and current values of the motor in the synchronous coordinate system and transmitting the converted voltage and current values to the second counter electromotive force estimator. .

The axis transformation step sets an estimated synchronous coordinate system based on the estimated D-axis with respect to the actual D-axis of the rotor of the motor, and uses the estimated synchronous coordinate system as the synchronous coordinate system to convert the voltage and current values of the motor. Available. In this case, the axis transformation step may set the estimated synchronization coordinate system based on the first estimated value for the angle of the rotor of the electric motor obtained from the first physical quantity information.

According to the present invention, it is possible to implement an apparatus and method for estimating the rotor position/speed that can improve the performance of the model-based sensorless control in a wide operation area including both the low-speed and high-speed operation areas of the PMSM.

)에 포함되는 오차가 PLL의 적분기에 누적되어 센서리스 제어 성능이 저하되는 현상)을 상호 보완적으로 해결할 수 있는 장점이 있다. 따라서 넓은 운전 영역에 걸쳐서 PMSM의 모델 기반 센서리스 제어 방식의 안정적인 성능을 확보할 수 있다.According to the first embodiment of the present invention, by using a hybrid method combining a magnetic flux estimation method using a stationary coordinate system voltage equation and a back electromotive force estimation method using a synchronous coordinate system voltage equation, the problem of the magnetic flux estimator using an integrator and HPF ( A phenomenon in which sensorless control performance deteriorates due to an increase in the error of the sensorless position estimation value due to phase lead in the low-speed operation region) and a problem in the method of estimating the back EMF from the synchronous coordinate system voltage equation (due to nonlinearity of the inverter and parameter fluctuations of PMSM) The estimated value for the position error due to

) has the advantage of complementarily solving the phenomenon that the sensorless control performance deteriorates due to the accumulation of errors in the integrator of the PLL. Therefore, it is possible to secure the stable performance of the model-based sensorless control method of PMSM over a wide operating area.

According to the second embodiment of the present invention, by using a hybrid method combining the back EMF estimation method using the stationary coordinate system voltage equation and the back EMF estimation method using the synchronous coordinate system voltage equation, the back EMF estimation method using the stationary coordinate system voltage equation and The disadvantages of the back EMF estimation method using the synchronous coordinate system voltage equation can be resolved complementary to each other.

According to the present invention, model-based sensorless control methods based on mathematical models having different main operation areas are combined complementary to each other, but not simply combined in parallel, but sequentially combined to compensate for each other's shortcomings. A new sensorless control method can be implemented.

According to the present invention, the disadvantages between the model-based sensorless control schemes that are complementary to each other can be healed by mutual advantages. For example, by using the advantages of the synchronous coordinate system back EMF estimation method, the disadvantages of the stationary coordinate system back EMF estimation method or the stationary coordinate system magnetic flux estimation method can be solved. Through this, stable sensorless control can be performed in a wide operation range from low to high speed.

The model-based sensorless control method according to the configuration of the present invention is not limited to selectively or parallelly combining sensorless control methods of the prior art, but is combined to be implemented as a new sensorless control method. The model-based sensorless control technique of the present invention obtained by this is not selectively applied for each specific condition, and a single technique can be applied over a wide operating area, and a stable sensorless control function can be implemented in a wide operating area. .

1 is a block diagram showing a general PMSM sensorless vector control system in the technical field of the present invention.
2 is a block diagram illustrating functional elements of a model-based sensorless position/velocity estimator of a typical PMSM in the technical field of the present invention.
Fig. 3 is a space vector diagram showing the relation between coordinate axes of PMSM.
4 is an embodiment of a detailed configuration of a position/velocity estimator using an estimated position error according to an embodiment of the present invention.
5 is a block diagram illustrating a PMSM sensorless control apparatus according to an embodiment of the present invention.
FIG. 6 is a detailed block diagram illustrating a first embodiment of the sensorless control device of FIG. 5 .
7 is a block diagram illustrating an embodiment of a detailed configuration of the magnetic flux estimator of FIG. 6 .
FIG. 8 is a block diagram showing an embodiment of the detailed configuration of the position/velocity detector of FIG. 6 .
9 is a detailed block diagram illustrating a second embodiment of the sensorless control apparatus of FIG. 5 .
10 is a block diagram illustrating a PMSM sensorless control apparatus using a back EMF estimator in a general synchronization coordinate system in the technical field of the present invention as a comparative example of the present invention.
11 is a diagram illustrating a waveform of a simulation result of PMSM sensorless control according to an embodiment of the present invention.

In addition to the above objects, other objects and features of the present invention will become apparent through the description of the embodiments with reference to the accompanying drawings.

A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

The present invention discloses a sensorless control apparatus and method for a permanent magnet synchronous motor (PMSM). In general, sensorless control is a technology for estimating information necessary to control a motor from the voltage and current supplied to the motor without using a physical sensor in the permanent magnet motor, and controlling the permanent magnet motor based on the estimated information. means

Among the configurations of the present invention, the contents known to those skilled in the art before the application of the present invention will be described as part of the configuration of the present invention in the present specification as necessary, but if it is thought that the facts obvious to those skilled in the art may obscure the gist of the invention, the description is omitted. can do. In addition, the items omitted in this specification are cited in the prior documents cited in the present application specification, for example, Korean Patent Publication KR 10-1329132 "Sensorless control device of a permanent magnet motor", Korean Patent Application Laid-Open KR 10-2020 -0046692 "Sensorless Control Method of Electric Motor", Korean Patent Publication KR 10-1961106 "Sensorless Control Method and Apparatus", "Evaluation of Back-EMF Estimators for Sensorless Control of Permanent Magnet Synchronous Motors", Lee, Kwang-Woon and Ha, Jung-Ik, Journal of Power Electronics, vol. 12, no. 4, pp. 604-614, Jul. 2012., and “Active flux concept for motion-sensorless unified AC drives”, I. Boldea, M. C. Paicu, and G. D. Andreescu, IEEE Trans. Power Electron., vol. 23, no. 5, pp. 2612-2618, Sep. By notifying those skilled in the art through 2008 and the like, it can be replaced by description.

Some of the contents disclosed in these prior documents are related to the problems to be solved by the present invention, and some of the solutions adopted by the present invention are commonly applied to these prior documents.

1 to 4 are diagrams illustrating components adopted in an embodiment of the present invention. At least a part of FIGS. 1 to 4 shows the prior art related to the present invention, and may be different from the prior art recognized under the patent law because it includes a modified part to be applied to the configuration of the present invention if necessary. .

In the description of FIGS. 1 to 11 below, matters considered as well-known techniques widely known in the technical field of the present invention may be substituted for description by omitting the description as necessary in order not to obscure the point, or by citing the prior literature. .

In addition, some or all of the configuration of the prior literature cited above and the prior literature cited thereafter is related to the problem to be solved by the present invention, and some of the solutions adopted by the present invention may be borrowed from the prior literature.

Only matters commonly included in order to embody the present invention among those disclosed in the prior literature will be considered as part of the configuration of the present invention.

Hereinafter, details of the present invention will be described with reference to the embodiments of FIGS. 1 to 11 .

1 is a block diagram showing a typical PMSM sensorless vector control system 100 in the technical field of the present invention.

The control system 100 is a component for performing sensorless vector control for a permanent magnet synchronous motor (PMSM) 120, a rotor position/speed estimator 110, a speed controller 130, a current controller 132 , and a PWM pattern generator 140 . The control command generated by the PWM pattern generator 140 is transmitted to the PMSM 120 through the three-phase inverter 142 . The current sensor 150 senses the current of the PMSM 150 and transmits phase current information to the rotor position/speed estimator 110 . Voltage information from the three-phase inverter 142 may be transmitted to the rotor position/speed estimator 110 . The rotor position/speed estimator 110 estimates the position (electrical angle) and speed of the rotor of the PMSM 120 , and transmits the estimated position/velocity information to the DQ converter 152 . The DQ converter 152 transmits the current information based on the DQ axis to the current controller 132 through the DQ axis conversion, and the speed information estimated by the rotor position/speed estimator 110 is transferred to the speed controller 130 . . The speed controller 130 generates a DQ-axis current command based on the speed error between the command speed and the estimated speed and transmits it to the current controller 132 .

The PMSM 120 has advantages of high energy efficiency and high power density per unit volume compared to other electric motors, and thus is widely used in all industries from home appliances such as refrigerators, air conditioners and washing machines to electric vehicles. As a control method of the PMSM 120 , a Field Oriented Control (FOC) method is widely used. For reference, FOC is also called vector control. In the FOC method, the flux component current (hereinafter referred to as the D-axis current) and the torque component current (hereinafter also referred to as the Q-axis current) can be independently controlled. A process of detecting the D-axis and Q-axis currents from the phase current (called DQ conversion) is required. DQ conversion requires information on the electrical angle of the PMSM rotor, and a sensor such as a Hall sensor, optical encoder, or resolver is generally used to detect the electrical angle of the PMSM rotor.

As described above, the use of such a rotor position detection sensor increases the cost of the PMSM driving system, and causes a problem in that the reliability of the PMSM driving system is deteriorated due to sensor failure. Accordingly, a sensorless control method for controlling the PMSM 120 by estimating the electric angle of the rotor from the voltage and current supplied to the PMSM 120 as shown in FIG. 1 is adopted in the present invention.

As described above, various sensorless control methods of the PMSM 120 have been proposed so far, and these methods can be largely divided into a signal injection method and a model-based counter electromotive force (or magnetic flux) estimation method.

In the signal injection method, a high frequency voltage signal higher than the driving frequency of the PMSM 120 is applied, and the electric angle of the rotor is estimated using the resulting high frequency current response. The sensorless control method of the signal injection method uses a change in the stator winding inductance of the PMSM 120 according to a change in the rotor position of the PMSM 120, and an IPM (Interior Permanent Magnet) having a structure in which a permanent magnet is embedded in the rotor. It is known that it is applicable only to type PMSM. The signal injection sensorless control method can estimate the rotor position information even when the IPM type PMSM is stopped or operated at low speed. However, torque pulsation occurs in the PMSM 120 due to high-frequency signal injection, which has a disadvantage in that vibration and noise are greatly generated. Also, iron loss in the PMSM 120 tends to greatly increase due to the application of a high frequency voltage. Therefore, it is known that the signal injection sensorless control method is limitedly used only in the stop and low-speed operation regions for the IPM type PMSM.

The sensorless control method of the model-based counter electromotive force (or magnetic flux) estimation method estimates the counter electromotive force (or magnetic flux) in the stator winding generated by the permanent magnet of the rotor using the voltage and current information applied to the PMSM 120 and , extracts the rotor electric angle information included in the estimated counter electromotive force (or magnetic flux) to control the PMSM 120 . In the model-based sensorless control method, since a high-frequency signal is not separately injected, torque pulsation is relatively small, and it is applicable to both IPM type PMSM and SPM (Surface Permanent Magnet) type PMSM. However, in the low-speed operation region where the PMSM 120 is stopped or 2 to 5% of the rated speed or less, the non-linearity of the inverter used for driving the PMSM and the effect of electrical noise caused by the PWM of the inverter are stable sensorless It is known to be very difficult to control. Therefore, the model-based sensorless control method is mainly used in areas other than the stop and low-speed operation areas. In addition, academia and industry are continuously conducting research to improve the performance of the model-based sensorless control method in the low-speed operation area of PMSM.

The present invention proposes a sensorless control apparatus and method for estimating the position and speed of a rotor by a more improved method for sensorless control in the rotor position/speed estimator 110 of FIG. 1 .

2 is a block diagram illustrating functional elements of a model-based sensorless position/velocity estimator of a typical PMSM in the technical field of the present invention.

To date, various model-based sensorless position/velocity estimation methods targeting the PMSM 120 have been proposed. 2 shows functional elements common to various model-based sensorless position/velocity estimation methods. In FIG. 2 , the back EMF (or magnetic flux) estimator 220 estimates the back EMF (or magnetic flux) using a voltage equation corresponding to the mathematical model 210 of the PMSM and voltage and current applied to the PMSM 120 . The estimated back electromotive force (or magnetic flux) includes rotor position information. In FIG. 2 , the rotor position/speed estimator 230 estimates the position and speed of the rotor using position information included in the estimated counter electromotive force (or magnetic flux). Model-based sensorless position estimation methods are detailed according to how each of the functional components (mathematical model 210, back EMF/magnetic flux estimator 220, rotor position/speed estimator 230) shown in FIG. 2 are configured. characteristics may vary.

Examples of functional components (mathematical model 210, back-EMF/magnetic flux estimator 220, rotor position/velocity estimator 230) are described in the above-mentioned prior literature "Evaluation of Back-EMF Estimators for Sensorless Control of Permanent Magnet" Synchronous Motors", Lee, Kwang-Woon and Ha, Jung-Ik, Journal of Power Electronics, vol. 12, no. 4, pp. 604-614, Jul. 2012., and “Active flux concept for motion-sensorless unified AC drives”, I. Boldea, M. C. Paicu, and G. D. Andreescu, IEEE Trans. Power Electron., vol. 23, no. 5, pp. 2612-2618, Sep. 2008, etc., can identify the main characteristics.

Fig. 3 is a space vector diagram showing the relation between coordinate axes of PMSM. 3 shows the relationship between the coordinate axes for performing vector control for the PMSM 120 of the present invention.

축은 정지 좌표계이고, DQ 축(dq 축)은 회전자의 실제 D축(자속 축)을 기준으로 하는 좌표계이다.

축은 어떤 방법으로든 실제의 D축을 추정한, 추정된 D축을 기준으로 하는 좌표계이다. 본 명세서의 이후에서,

축은 추정된 D축을 의미하며,

축은

축에 직교하는 축을 의미한다. in Figure 3

The axis is a stationary coordinate system, and the DQ axis (dq axis) is a coordinate system based on the actual D axis (magnetic flux axis) of the rotor.

The axis is a coordinate system based on the estimated D-axis, in which the actual D-axis is estimated in some way. Later in this specification,

axis means the estimated D-axis,

the axis

An axis orthogonal to an axis.

축과 d축 사이의 각도인

은 실제 회전자의 전기 각에 해당하고,

축과

축 사이의 각도인

은 추정된 회전자의 전기 각을 의미한다. Therefore, in Figure 3

The angle between the axis and the d axis is

corresponds to the electric angle of the actual rotor,

axis

the angle between the axes

is the estimated electric angle of the rotor.

Hereinafter, a sensorless control method employed in embodiments of the present invention will be described based on a mathematical model. These sensorless control methods and mathematical models may include not only known facts before the filing of the present invention, but also modified contents to be applied to the configuration of the present invention.

A. Sensorless control method based on back electromotive force estimation using stationary coordinate system voltage equation

The voltage equation of the PMSM 120 in the stationary coordinate system is given by Equations 1 and 2 below.

[Equation 1]

[Equation 2]

는 각각

축과

축에서의 PMSM(120) 고정자(stator) 권선 전압을,

는 각각

축과

축에서의 PMSM(120) 고정자 권선 전류를 의미한다. R은 고정자 권선 저항, p는 미분 연산자(differential operator)를 나타내며,

은 회전자의 영구자석으로 인한 자속(역기전력 상수)(permanent magnet flux linkage)를 의미한다. Ld와 Lq는 각각 PMSM(120) 고정자 권선의 D축 및 Q축 인덕턴스이고, L₀ 및 L₁ 은 수학식 2에 의하여 정의된다.

are each

axis

PMSM 120 stator winding voltage at the shaft,

are each

axis

Means the PMSM 120 stator winding current in the shaft. R is the stator winding resistance, p is the differential operator,

is the magnetic flux (reverse electromotive force constant) due to the permanent magnet of the rotor (permanent magnet flux linkage). Ld and Lq are the D-axis and Q-axis inductances of the stator winding of the PMSM 120, respectively, and L ₀ and L ₁ are defined by Equation (2).

은 회전자 위치(rotor position), 즉, 전기 각이고,

은 회전자 각속도(rotor angular velocity)이다.

is the rotor position, i.e. the electric angle,

is the rotor angular velocity.

Equation 1 is expressed using Equation 3 below for extended EMF Eex, as shown in Equation 4 below.

[Equation 3]

[Equation 4]

id and iq of Equation 3 are the stator voltage and stator current of the PMSM 120 shown based on the D-axis and the Q-axis, respectively, and the right term of Equation 4 corresponds to the back electromotive force. -EMF Estimators for Sensorless Control of Permanent Magnet Synchronous Motors", Lee, Kwang-Woon and Ha, Jung-Ik, Journal of Power Electronics, vol. 12, no. 4, pp. 604-614, Jul. 2012., and “Active flux concept for motion-sensorless unified AC drives”, I. Boldea, M. C. Paicu, and G. D. Andreescu, IEEE Trans. Power Electron., vol. 23, no. 5, pp. 2612-2618, Sep. Since it can be clearly understood through 2008 and the like, a detailed description thereof will be omitted.

축과

축에서의 역기전력

를 하기 수학식 5와 같이 추정할 수 있고(

), 회전자의 전기 각에 대한 추정 값

은 수학식 6에 의하여 추정 역기전력

로부터 구할 수 있다. From Equation 4 using a general observer (not shown) of sensorless control, etc.

axis

Back EMF at the axis

can be estimated as in Equation 5 below (

), an estimate of the electric angle of the rotor

is the estimated back electromotive force by Equation (6)

can be obtained from

[Equation 5]

[Equation 6]

In the method of estimating the back electromotive force using the stationary coordinate system voltage equation, the rotor electric angle can be directly obtained through the ArcTangent operation as shown in Equation 6 above. An observer used for back EMF estimation generally has a characteristic of a low pass filter (LPF). In the LPF, as the frequency of the input signal increases, the phase difference between the input signal and the output signal increases. As shown in Equation 5, since the back EMF in the stationary coordinate system is an AC signal, there is a phase difference between the back EMF estimated through the observer and the actual back EMF, and this phase difference increases as the speed increases. Therefore, the sensorless control method for estimating the back EMF using the stationary coordinate system voltage equation and obtaining the rotor position from the estimated back EMF is due to the phase error occurring in the back EMF estimator when the PMSM 120 is operated with a frequency greater than or equal to the bandwidth of the back EMF observer. There is a disadvantage in that the sensorless position estimation error greatly increases.

항이 0이 된다. 그러나 Ld와 Lq의 값이 서로 다른 IPM 타입 PMSM의 경우에는 전압 방정식에서

항을 무시할 수 없으며, 수학식 4의 전압 방정식을 이용하여 역기전력을 추정하기 위해서는 실제 속도 대신에 추정 속도를 사용해야 한다. 따라서 IPM 타입 PMSM의 경우, 과도 상태 또는 저속 운전 조건에서 실제 속도와 추정 속도 사이에 발생할 수 있는 오차는 정지 좌표계 전압 방정식을 이용한 역기전력 추정 기반의 센서리스 제어 방식의 성능을 저하시키는 원인이 될 수 있다.In the case of the SPM type PMSM, since the relationship Ld = Lq is established, in the first term on the right of the voltage equation in Equation 4, the speed related

term becomes 0. However, in the case of an IPM type PMSM with different values of Ld and Lq, the voltage equation

The term cannot be ignored, and in order to estimate the back EMF using the voltage equation of Equation 4, the estimated speed should be used instead of the actual speed. Therefore, in the case of IPM-type PMSM, an error that may occur between the actual speed and the estimated speed in a transient or low-speed driving condition may cause deterioration of the performance of the sensorless control method based on the back EMF estimation using the stationary coordinate system voltage equation. .

B. Sensorless control method based on back EMF estimation using synchronous coordinate system voltage equation

축에서 PMSM(120)의 전압 방정식은 하기 수학식 7과 같이 주어진다. Referring back to Figure 3,

The voltage equation of the PMSM 120 on the axis is given as in Equation 7 below.

[Equation 7]

는

축에서 PMSM(120)의 고정자 전압이고,

는

축에서 PMSM(120)의 고정자 전류이다.

은 회전자의 전기 각에 대한 추정 값

으로부터 얻어지는 회전자의 추정 각속도이다.

Is

is the stator voltage of the PMSM 120 on the axis,

Is

The axis is the stator current of the PMSM 120 .

is the estimated value for the electric angle of the rotor

It is the estimated angular velocity of the rotor obtained from

은

축을 기준으로 나타내는 역기전력이며, 구체적으로는 확장된 역기전력 Eex에 대하여 하기 수학식 8과 같이 나타낼 수 있다.The second term from the right of Equation 7

silver

It is a counter electromotive force expressed based on the axis, and specifically, the extended counter electromotive force Eex can be expressed as in Equation 8 below.

[Equation 8]

에 대한 추정 값

을 하기 수학식 9에 의하여 구할 수 있다.When the back EMF is estimated in the synchronous coordinate system expressed by Equation 8 from the observer based on Equation 7, the error between the actual electric angle of the rotor and the estimated electric angle

estimated value for

can be obtained by Equation 9 below.

[Equation 9]

는 각각

의 추정값을 의미한다. 수학식 9를 이용하여 위치 오차 추정값

을 구한 후, 도 4와 같은 위상 동기화 루프(Phase Locked Loop, PLL) 등을 이용하여 PMSM(120)의 회전자 전기 각

에 대한 추정 값

과 전기 각속도

에 대한 추정 값

을 추정할 수 있다. in Equation 9

are each

means an estimate of Position error estimate using Equation 9

After obtaining , the rotor electrical angle of the PMSM 120 using a phase locked loop (PLL), etc. as shown in FIG. 4 .

estimated value for

and electric angular velocity

estimated value for

can be estimated.

4 is an embodiment of a detailed configuration of a position/velocity estimator 230 using an estimated position error according to an embodiment of the present invention.

이 비례-적분 제어기(PI 제어기)(410)에 전달되고, 비례-적분 제어기(410)를 통해 구해진 회전자 전기 각속도 추정값

이 적분기(420)로 전달되어 회전자 전기 각 추정값

이 도출된다. Position error estimate

The rotor electric angular velocity estimate value transmitted to this proportional-integral controller (PI controller) 410 and obtained through the proportional-integral controller 410 .

This is passed to the integrator 420 to estimate the rotor electrical angle.

this is derived

에는 위치 오차 정보

가 포함되어 있으며, 정상 상태에서 추정 역기전력

은 직류 신호로 볼 수 있다. 따라서 역기전력 추정에 사용되는 관측기에서 발생하는 위상 지연 효과는 거의 무시할 수 있다. 따라서 동기 좌표계 전압방정식을 이용한 역기전력 추정 기반의 센서리스 제어 방식은 정지 좌표계 전압 방정식을 이용한 역기전력 추정 기반 센서리스 제어 방식 대비 고속에서의 센서리스 제어 성능이 우수한 장점을 갖는다. 그러나 인버터의 비선형성, PMSM(120)의 파라미터 변동 등으로 인해 위치 오차 추정값

에 포함되는 오차 성분이 위치/속도 추정에 사용되는 PLL의 적분기에 누적될 수 있고, 이러한 현상은 특히 저속 운전 영역에서의 센서리스 제어 성능을 악화시키는 원인이 된다. 이로 인해 저속 운전 영역에서는 위치/속도 추정에 사용되는 PLL의 대역폭을 낮게 설정해야 하며, 결과적으로 저속 운전 영역에서 큰 부하가 걸리는 응용 분야에서는 만족스러운 센서리스 제어 성능을 얻기가 어렵다.Referring back to FIG. 3 , as shown in Equation 8, the back EMF estimated from the synchronous coordinate system voltage equation

In the position error information

is included, and the estimated back EMF in the steady state

can be viewed as a direct current signal. Therefore, the phase delay effect generated by the observer used for the back EMF estimation is almost negligible. Therefore, the sensorless control method based on the back EMF estimation using the synchronous coordinate system voltage equation has the advantage of superior sensorless control performance at high speed compared to the sensorless control method based on the back EMF estimation using the stationary coordinate system voltage equation. However, due to the non-linearity of the inverter, the parameter fluctuation of the PMSM 120, etc., the estimated position error value

An error component included in ? may be accumulated in an integrator of a PLL used for position/velocity estimation, and this phenomenon causes deterioration of sensorless control performance, particularly in a low-speed operation region. For this reason, it is necessary to set the bandwidth of the PLL used for position/velocity estimation low in the low-speed operation region, and as a result, it is difficult to obtain satisfactory sensorless control performance in the application field with a large load in the low-speed operation region.

항이 포함된다. SPM 타입 PMSM의 경우 Ld=Lq의 관계가 성립하기 때문에 수학식 7의

항이 사실상 상쇄된다. 그러나 IPM 타입 PMSP의 경우에는

항이 전압 방정식에 영향을 주기 때문에 실제 속도와 추정 속도 사이에 오차가 존재하는 과도 상태 또는 저속 운전 조건에서 센서리스 제어 성능이 저하될 수 있다.In the voltage equation of Equation 7, there is an error corresponding to the error between the actual speed and the estimated speed.

clause is included. In the case of the SPM type PMSM, since the relationship Ld = Lq is established, Equation 7

terms are virtually cancelled. However, in the case of IPM type PMSP,

Since the term affects the voltage equation, sensorless control performance may deteriorate in transient or low-speed driving conditions where there is an error between the actual speed and the estimated speed.

C. Sensorless control method based on magnetic flux estimation using stationary coordinate system voltage equation

축에서의 자속을

라 하고,

축에서의 자속을

이라 하면, PMSM(120)의 전압 방정식은 하기 수학식 10과 같이 주어진다. in a stationary coordinate system

magnetic flux on the axis

say,

magnetic flux on the axis

, the voltage equation of the PMSM 120 is given as in Equation 10 below.

[Equation 10]

축에서의 자속

및

축에서의 자속

과 DQ 축에서의 자속

사이에는 하기 수학식 11의 관계가 성립한다.At this time

magnetic flux on the axis

and

magnetic flux on the axis

and magnetic flux in the DQ axis

The relationship of the following formula (11) is established between

[Equation 11]

은 하기 수학식 12와 같이 나타내어진다.Flux in DQ axis

is represented by Equation 12 below.

[Equation 12]

를 하기 수학식 13과 같이 정의할 수 있다. At this time, the active flux

can be defined as in Equation 13 below.

[Equation 13]

축에서의 자속

및

축에서의 자속

을 하기 수학식 14와 같이 표현할 수 있다.Using the effective magnetic flux defined in Equation 13 above,

magnetic flux on the axis

and

magnetic flux on the axis

can be expressed as in Equation 14 below.

[Equation 14]

Using Equation 14, Equation 10 can be expressed as Equation 15 below.

[Equation 15]

축에서의 유효 자속

및

축에서의 유효 자속

을 하기 수학식 16 및 수학식 17과 같이 구할 수 있다. from Equation 15

Effective magnetic flux in the axis

and

Effective magnetic flux in the axis

can be obtained as in Equations 16 and 17 below.

[Equation 16]

[Equation 17]

축에서의 유효 자속

및

축에서의 유효 자속

을 이용하여 회전자 전기각

을 하기 수학식 18과 같이 구할 수 있다.

Effective magnetic flux in the axis

and

Effective magnetic flux in the axis

Rotor electric angle using

can be obtained as in Equation 18 below.

[Equation 18]

축에서의 유효 자속

및

축에서의 유효 자속

을 구하기 위해서는 적분이 필요하다. 전압과 전류에 포함된 작은 오차 성분들이 적분기에 누적이 되면 수학식 16 및 수학식 17을 통해 구한 자속에는 오차가 발생하게 된다. 이러한 문제점을 해결하기 위해 수학식 16 및 수학식 17의 적분기 출력에 고역 통과 필터(High Pass Filter, HPF)를 사용하여 적분기의 출력에서 DC 성분을 차단하는 방식이 일반적으로 사용되고 있다. 적분기와 HPF의 직렬 연결은 LPF와 동일한 특성을 제공하기 때문에 실제 구현에서는 적분기와 HPF 대신에 LPF를 사용한다.As shown in Equation 17 above,

Effective magnetic flux in the axis

and

Effective magnetic flux in the axis

An integral is needed to find When small error components included in voltage and current are accumulated in the integrator, an error occurs in the magnetic flux obtained through Equations 16 and 17. In order to solve this problem, a method of blocking the DC component at the output of the integrator by using a high pass filter (HPF) at the output of the integrator of Equations 16 and 17 is generally used. Since the serial connection of the integrator and the HPF provides the same characteristics as the LPF, the actual implementation uses the LPF instead of the integrator and the HPF.

When the HPF is used to block the DC component of the integrator in the magnetic flux estimation, a large phase lead occurs between the input signal and the output signal of the HPF below the cutoff frequency of the HPF. That is, when estimating magnetic flux by combining the integrator and HPF, an estimation error due to phase lead occurs between the actual magnetic flux and the estimated magnetic flux. , when the operating frequency of the PMSM 120 is sufficiently larger than the cut-off frequency of the HPF, an error due to the phase leading hardly occurs.

Since the sensorless control method based on the magnetic flux estimation using the stationary coordinate system voltage equation does not use the speed information of the PMSM 120, the effect due to an error between the actual speed and the estimated speed in a transient state can be ignored. However, in the low-speed operation region, as mentioned above, there is a disadvantage in that the sensorless control performance is deteriorated due to the phase lead in the magnetic flux estimator.

등) 값들을 정확하게 구할 수 없고, 적분기 drift를 방지하기 위해 별도의 제어기를 추가해야 하므로 그 구성이 복잡해지는 단점이 있다.For the purpose of improving the problems of the existing magnetic flux estimation method, prior literature (I. Boldea, MC Paicu, and GD Andreescu, "Active flux concept for motion-sensorless unified AC drives," IEEE Trans. Power Electron., vol. 23, no 5, pp. 2612-2618, Sep. 2008) calculates the magnetic flux using the parameters of the PMSM 120 based on the estimated rotor electric angle, and uses the error between the calculated magnetic flux and the magnetic flux obtained through the integrator. Therefore, a method to prevent DC drift in the integrator used for magnetic flux estimation is presented. This method can show superior performance at low speed compared to the simple integration-based magnetic flux estimation method. However, the actual parameters (Ld, Lq, and

etc.) values cannot be accurately obtained, and a separate controller must be added to prevent integrator drift, so the configuration becomes complicated.

It can be seen that the characteristics of PMSM sensorless control methods based on counter electromotive force or magnetic flux estimation are determined according to the coordinate system in which the voltage equation corresponding to the mathematical model of the motor is expressed. Since the model-based PMSM sensorless control methods of the prior art are based on one of the above-mentioned three mathematical models, it is difficult to implement stable sensorless control performance in a wide operation range ranging from low-speed and high-speed operation areas.

For example, the stationary coordinate system-based back EMF estimation method has the advantage of directly obtaining rotor position information from the estimated back EMF, whereas the position estimation error as the operation speed of the PMSM 120 increases due to the phase delay characteristic of the back EMF estimator may increase. In addition, in the case of the IPM type PMSM, since the estimated speed is used for estimating the back EMF, the sensorless control performance can be controlled in a low speed region. Due to this, there is a disadvantage that the bandwidth of the back EMF estimator and the PLL may be limited in the low speed region.

In addition, the synchronous coordinate system-based back EMF estimation method has an advantage in that performance degradation due to phase delay in the back EMF estimator is very small because the estimated back EMF is a DC signal. However, noise signals included in the estimated error error are accumulated in the integrator of the PLL, and sensorless control performance may be degraded in the low-speed region. Due to this, there is a disadvantage in that the bandwidth of the back EMF estimator and the PLL is limited in the low-speed region.

Meanwhile, in the static coordinate system-based magnetic flux estimation method, 1) there is no performance degradation due to an error in the estimation speed because velocity information is not used in the magnetic flux estimation, and 2) the HPF bandwidth is There is an advantage of no phase delay in the high-speed region out of . On the other hand, this method has a disadvantage in that a position estimation error due to a phase lead occurs significantly in the low-speed region.

According to the embodiments of the present invention, since the magnetic flux estimation (or counter electromotive force estimation) based on the stationary coordinate system voltage equation and the counter electromotive force estimation method based on the synchronous coordinate system voltage equation are combined and used in a hybrid form, each disadvantage is taken advantage of while taking advantage of each disadvantage. can complement each other. As a result, according to the embodiments of the present invention, there is no need to selectively apply the sensorless control method according to the operation area, and it is possible to realize stable sensorless control performance while using a single sensorless control method over a wide operation area. have.

5 is a block diagram illustrating a PMSM sensorless control apparatus according to an embodiment of the present invention.

The PMSM sensorless control apparatus of the present invention may particularly relate to the rotor position/speed estimator 110 of FIG. 1 .

The PMSM sensorless control apparatus of the present invention includes a first estimator 510 for estimating first physical quantity information describing the operation of the PMSM motor 120 in a stationary coordinate system, and a PMSM motor 120 obtained based on the first physical quantity information. A second estimator 530 for estimating second physical quantity information representing the back electromotive force of the PMSM motor 120 in a synchronous coordinate system based on a first estimated value for the angle of the rotor, and a first estimated value using the second physical quantity information and a position/speed detector 550 for generating position and speed information of the rotor of the PMSM motor 120 for which an error included in the angle of Δ is compensated. In this case, the synchronous coordinate system of the second estimator may be understood as a synchronous coordinate system based on the angle of the first physical quantity information. Also, the position/velocity detector may be understood to generate position and velocity information of the rotor in which an error included in the angle of the first physical quantity information is compensated.

The first physical quantity information may be a magnetic flux of the PMSM motor 120 .

The first physical quantity information may be a counter electromotive force of the PMSM motor 120 .

FIG. 6 is a detailed block diagram illustrating a first embodiment of the sensorless control device of FIG. 5 .

The first embodiment of FIG. 6 is an embodiment on the assumption that the first physical quantity information is the magnetic flux of the PMSM motor 120 . The first estimator 510 includes a magnetic flux estimator 612 for estimating the magnetic flux of the PMSM motor 120 as first physical quantity information in the stationary coordinate system, and the angle of the rotor of the PMSM motor 120 based on the first physical quantity information. and a magnetic flux angle calculator 614 that generates a first estimate for .

The second estimator 530 includes a second counter electromotive force estimator 632 for estimating second physical quantity information representing the counter electromotive force of the PMSM motor 120 in a synchronous coordinate system based on the first estimated value, and PMSM based on the first physical quantity information. A (magnetic flux) angular velocity calculator 636 that calculates the angular velocity of the rotor of the electric motor 120 and transfers the angular velocity to the second counter electromotive force estimator 632, and the angular velocity and the second physical quantity information are included in the angle of the first estimated value It may include an angle error calculator 634 for calculating the calculated error.

The second estimator 530 converts the voltage and current values of the PMSM motor 120 in the stationary coordinate system into the voltage and current values of the PMSM motor 120 in the synchronous coordinate system and transmits them to the second counter electromotive force estimator 632 . (638) may be further included.

축)을 기준으로 하는 추정 동기 좌표계(

)를 설정하고, 추정 동기 좌표계를 PMSM 전동기(120)의 전압 및 전류 값을 변환하는 동기 좌표계로서 이용할 수 있다. 이때 축 변환기는 제1 물리량 정보에서 얻어지는 PMSM 전동기(120)의 회전자의 각도에 대한 제1 추정값을 기준으로 추정 동기 좌표계를 설정할 수 있다. The axis converter 638 provides an estimated D-axis (

The estimated synchronous coordinate system (

), and the estimated synchronous coordinate system can be used as a synchronous coordinate system for converting voltage and current values of the PMSM motor 120 . In this case, the axis converter may set the estimated synchronization coordinate system based on the first estimated value for the angle of the rotor of the PMSM motor 120 obtained from the first physical quantity information.

축에서의 유효 자속

및

축에서의 유효 자속

을 추정한다. 자속 추정기(612)의 입력은

좌표계에서 전압 (

), 및 전류(

)이고, 출력은

좌표계 기준으로 추정된 유효 자속 (

)이다.

좌표계에서 전압 (

)은 3상 인버터(142)의 상 전압 지령 (

)으로부터 하기 수학식 19 및 수학식 20을 이용하여 구할 수 있다. The magnetic flux estimator 612 uses the voltage equation in the stationary coordinate system as shown in Equations 15 to 17.

Effective magnetic flux in the axis

and

Effective magnetic flux in the axis

to estimate The input of the magnetic flux estimator 612 is

voltage in the coordinate system (

), and the current (

), and the output is

Estimated effective magnetic flux based on the coordinate system (

)to be.

voltage in the coordinate system (

) is the phase voltage command (

) can be obtained using Equations 19 and 20 below.

[Equation 19]

[Equation 20]

좌표계에서 전류(

)는 3상 인버터(142)의 상 전류(

)로부터 하기 수학식 21 및 수학식 22를 이용하여 구할 수 있다.

In the coordinate system, the current (

) is the phase current (

) can be obtained using Equations 21 and 22 below.

[Equation 21]

[Equation 22]

FIG. 7 is a block diagram illustrating an embodiment of a detailed configuration of the magnetic flux estimator 612 of FIG. 6 .

)와 HPF(

)의 곱에 대응하는 LPF(

)으로 구현된다. 따라서 PMSM(120)의 운전 주파수가 LPF의 차단 주파수(

) 이하인 저속 운전 영역에서 도 6의 자속 추정기(612)가 출력하는 유효 자속의 위상은 실제 값보다 앞서게 된다.Referring to FIG. 7 , the integrator for estimating the effective magnetic flux is an integrator (

) and HPF(

) corresponding to the product of LPF(

) is implemented. Therefore, the operating frequency of the PMSM 120 is the cutoff frequency of the LPF (

) or less, the phase of the effective magnetic flux output from the magnetic flux estimator 612 of FIG. 6 is ahead of the actual value.

에서 자속 각도(

)를 계산할 수 있다.Referring back to FIG. 6 , the magnetic flux angle calculator 614 performs an inverse tangent operation on the output signals of the magnetic flux estimator 612 as shown in Equation 18 to perform a stationary coordinate system.

at the magnetic flux angle (

) can be calculated.

)의 각속도(

)를 계산할 수 있다. 자속 각속도 연산기(636)는 자속 각도(

)의 미분을 통해 각속도(

)를 구할 수 있고, 미분에 의한 노이즈의 영향이 크게 발생하는 경우 별도의 PLL을 이용하여 각속도(

)를 구할 수 있다. 각도 정보에 대한 PLL을 통해 각속도를 구하는 방법은 모터 구동 분야에서 통상의 지식으로 구현할 수 있기에 이에 대한 자세한 설명은 생략하기로 한다.The magnetic flux angular velocity calculator 636 calculates the magnetic flux angle (

) of the angular velocity (

) can be calculated. The magnetic flux angular velocity calculator 636 calculates the magnetic flux angle (

) through the derivative of the angular velocity (

) can be obtained, and if the influence of noise due to differentiation is large, use a separate PLL to obtain the angular velocity (

) can be obtained. Since the method of obtaining the angular velocity through the PLL for the angle information can be implemented by common knowledge in the field of motor driving, a detailed description thereof will be omitted.

)를 하기 수학식 23 및 수학식 24에 적용하여 자속 기반 추정 동기 좌표계(

) 기준 전압(

) 및 전류(

)에 대한 축 변환을 수행할 수 있다.The axis transducer 638 is the magnetic flux angle (

) by applying the following Equations 23 and 24 to the magnetic flux-based estimated synchronization coordinate system (

) reference voltage (

) and current (

) for axis transformation.

[Equation 23]

[Equation 24]

)를 기준으로 하는 추정 동기 좌표계(

)에서 전압 방정식과 관측기를 이용하여 회전자 전기각(

) 및 자속 각도(

) 사이의 오차 정보(

)를 포함하는 역기전력을 추정할 수 있다.The second back electromotive force estimator 632 is the magnetic flux angle (

) based on the estimated synchronous coordinate system (

) using the voltage equation and the observer in the rotor electric angle (

) and the magnetic flux angle (

) between the error information (

) can be estimated.

At this time, as an observer used for back EMF estimation, the preceding literature (Lee, Kwang-Woon and Ha, Jung-Ik, "Evaluation of Back-EMF Estimators for Sensorless Control of Permanent Magnet Synchronous Motors," Journal of Power Electronics., vol. 12 , no. 4, pp. 604-614, Jul. 2012.), various observers for estimating the back EMF from the voltage equation can be used. Since these observers can be regarded as general knowledge in the field related to sensorless control, a detailed description thereof will be omitted in the present invention.

)에서 성립하는 전압 방정식은 하기 수학식 25와 같이 나타낼 수 있다.Estimated Synchronous Coordinate System (

) can be expressed as Equation 25 below.

[Equation 25]

)의 역기전력 성분(

)은 확장된 역기전력 Eex에 대하여 하기 수학식 26과 같은 관계를 가진다.Estimated Synchronous Coordinate System (

) of the back EMF component (

) has the same relation as in Equation 26 below for the extended back electromotive force Eex.

[Equation 26]

If Equation 25 is expressed for an SPM type PMSM in which the relationship Ld=Lq is established, it can be simplified as Equation 27.

[Equation 27]

성분은 0이 아니지만, 수학식 25의 오른쪽 마지막 항에서는 전동기 회전자의 각속도(

) 및 제1 추정값(

)으로부터 얻어지는 각속도 성분(

) 간의 오차

와

이 곱해진 값이 포함된다. 이때 IPM 타입 PMSM에서 Ld와 Lq 간의 차이는 크지 않으므로 수학식 25의 오른쪽 마지막 항이 제1 추정값(

)을 기준으로 하는 추정 동기 좌표계(

)에서 역기전력 추정에 미치는 영향은 무시할 수 있을 정도로 작다. 따라서 수학식 27에서처럼

항의 영향이 제거되는 SPM 타입 PMSM 뿐 아니라, IPM 타입 PMSM 에서도

의 영향은 무시할 수 있을 정도로 작은 것을 알 수 있다.In the IPM type PMSM

The component is not 0, but in the last term on the right of Equation 25, the angular velocity (

) and the first estimate (

) from the angular velocity component (

) between

Wow

This multiplied value is included. At this time, since the difference between Ld and Lq in the IPM type PMSM is not large, the last term on the right of Equation 25 is the first estimated value (

) based on the estimated synchronous coordinate system (

), the effect on the back EMF estimation is negligible. Therefore, as in Equation 27

In addition to the SPM type PMSM in which the effect of the term is removed, the IPM type PMSM

It can be seen that the effect of is small enough to be negligible.

및 제1 추정값(

) 사이의 오차 정보

를 구할 수 있다.The angle error calculator 634 performs an inverse tangent operation on the output signals of the second counter electromotive force estimator 632 as shown in Equation 28.

and the first estimate (

) between the error information

can be obtained

[Equation 28]

를 제1 추정값(

)에 합산하면 수학식 29와 같이 원하는 위치 추정값

을 얻을 수 있다.Error information obtained through Equation (28)

is the first estimate (

), the desired position estimate value as shown in Equation 29

can get

[Equation 29]

)은 적분기와 HPF의 조합으로 구하는 경우가 많으므로 PMSM(120)의 운전 주파수가 HPF의 차단 주파수 이하인 경우 위상 앞섬으로 인한 오차가 발생된다. 이러한 위상 앞섬으로 인한 오차에 대한 정보는 제1 추정값(

)을 기준으로 하는 추정 동기 좌표계(

)에서의 전압 방정식으로부터 추정한 역기전력에 포함된다. 따라서 수학식 29와 같이 회전자 위치

를 구하면 위상 앞섬으로 인하여 발생하는 센서리스 위치 추정 오차를 보상할 수 있다.As previously described, the first estimate (

) is often obtained by a combination of the integrator and the HPF, so when the operating frequency of the PMSM 120 is less than or equal to the cutoff frequency of the HPF, an error due to the phase lead occurs. Information on the error due to this phase leading is the first estimate (

) based on the estimated synchronous coordinate system (

) is included in the back EMF estimated from the voltage equation in Therefore, the rotor position as in Equation 29

By obtaining , it is possible to compensate for the sensorless position estimation error caused by the phase lead.

에 PLL 기법을 적용하여 PMSM(120)의 센서리스 벡터 제어에 필요한 회전자 위치 및 속도에 대한 추정 값

을 출력할 수 있다. The position/velocity detector 550 is

Estimated values of rotor position and speed required for sensorless vector control of PMSM 120 by applying the PLL technique to

can be printed out.

8 is a block diagram illustrating an embodiment of a detailed configuration of the position/velocity detector 550 of FIG. 6 .

을 수신하고, 비례-적분 방식의 제어(PI 제어)를 통하여 각속도 추정값

을 얻는 비례-적분 제어기(810)를 포함한다. 또한 위치/속도 검출기(550)는 각속도 추정값

으로부터 위치 추정값

을 얻는 적분기(820)를 포함할 수 있다. 도 8의 위치/속도 검출기(550)의 동작의 상세한 원리는 모터 제어 분야에서는 일반화된 통상적인 지식으로 볼 수 있으므로 본 출원명세서에서는 이에 대한 자세한 설명은 생략한다. The position/velocity detector 550 is

, and the angular velocity estimate value through proportional-integral control (PI control)

and a proportional-integral controller 810 to obtain The position/velocity detector 550 also provides an angular velocity estimate.

position estimate from

It may include an integrator 820 to obtain Since the detailed principle of the operation of the position/speed detector 550 of FIG. 8 can be viewed as general knowledge in the field of motor control, a detailed description thereof will be omitted in the present specification.

9 is a detailed block diagram illustrating a second embodiment of the sensorless control apparatus of FIG. 5 .

The second embodiment of FIG. 9 is an embodiment on the assumption that the first physical quantity information is the counter electromotive force of the PMSM motor 120 . Since the operation of the position/velocity detector 550 of FIG. 9 is not significantly different from the operation of the position/velocity detector 550 of FIG. 6 , a redundant description will be omitted.

을 생성하는 역기전력 각도 연산기(914)를 포함할 수 있다. When the first physical quantity information is the counter electromotive force of the PMSM motor 120, the first estimator 510 includes a first counter electromotive force estimator 912 for estimating the counter electromotive force of the PMSM motor 120 as the first physical quantity information in the stationary coordinate system; and a first estimate for the angle of the rotor of the PMSM electric motor 120 based on the first physical quantity information.

It may include a back electromotive force angle calculator 914 that generates

에 대한 역기전력 추정값

을 얻을 수 있다. 앞에서 설명한 바와 같이 정지 좌표계

에 대한 역기전력 추정값

에는 회전자 위치 정보가 포함된다. 그러나 관측기가 LPF의 특성을 가지는 경우가 일반적이므로 PMSM(120)의 운전 주파수가 증가할수록 역기전력 추정값

의 위상 지연으로 인한 오차가 증가한다.The first back EMF estimator 912 is a stationary coordinate system using Equation 5 from an observer using Equation 4

Estimated back EMF for

can get As described earlier, a stationary coordinate system

Estimated back EMF for

includes rotor position information. However, since the observer generally has LPF characteristics, as the operating frequency of the PMSM 120 increases, the estimated value of the back EMF

The error due to the phase delay of

을 기준으로 하는 추정 동기 좌표계(

)의 전압 방정식으로부터 추정한 역기전력을 이용하여 역기전력 추정값

의 위상 지연으로 인한 오차를 보상할 수 있다.In the second embodiment of FIG. 9 , a first estimate of the rotor position obtained by the first estimator 510 is

Estimated synchronization coordinate system based on (

) using the back EMF estimated from the voltage equation of

It is possible to compensate for the error due to the phase delay of .

의 각속도 연산기(936)는 제1 추정값

의 각속도

를 계산할 수 있다. 축 변환기(938)는 제1 추정값

에 기반하여 설정된 추정 동기 좌표계(

)를 기준으로 전압 및 전류를 변환한다. 이러한 변환 과정은 하기 수학식 30 및 수학식 31에 의하여 표현될 수 있다.Back EMF based first estimate

Angular velocity calculator 936 of the first estimate

angular velocity of

can be calculated. Axis transducer 938 provides a first estimate

Estimated synchronization coordinate system established based on (

) to convert voltage and current. This conversion process can be expressed by Equations 30 and 31 below.

[Equation 30]

[Equation 31]

를 기준으로 하는 추정 동기 좌표계(

)에서 전압 방정식과 관측기를 이용하여 회전자 위치

및 제1 추정값

사이의 오차 정보

를 포함하는 역기전력

을 추정한다.The second back electromotive force estimator 932 included in the second estimator 530 is the first estimate value.

Estimated synchronization coordinate system based on (

) using the voltage equation and the observer to position the rotor

and a first estimate

error information between

back electromotive force including

to estimate

를 기준으로 하는 추정 동기 좌표계(

)에서 전압 방정식은 하기 수학식 32와 같이 나타내어질 수 있다. first estimate

Estimated synchronization coordinate system based on (

), the voltage equation may be expressed as Equation 32 below.

[Equation 32]

은 오차 정보

와 하기 수학식 33과 같은 관계를 가진다. back electromotive force

silver error information

and Equation 33 below.

[Equation 33]

에 대한 역탄젠트 연산을 수행하여 회전자 위치

및 제1 추정값

사이의 오차 정보

를 구할 수 있다. The angle error calculator 934 outputs signals of the second back EMF estimator 932 .

Perform an inverse tangent operation on the rotor position

and a first estimate

error information between

can be obtained

는 수학식 34와 같이 표현된다.In this case, the error information

is expressed as in Equation 34.

[Equation 34]

는 제1 추정값

에 합산되어 위치/속도 검출기(550)에 입력되고, 위치/속도 검출기(550)는 입력된 정보로부터 PLL을 이용하여 PMSM(120)의 센서리스 벡터 제어에 필요한 회전자 위치 및 속도에 대한 추정 값

을 출력할 수 있다. In the embodiment of Fig. 9, error information

is the first estimate

is added to and input to the position/speed detector 550, and the position/velocity detector 550 uses the PLL from the input information to estimate the rotor position and speed required for sensorless vector control of the PMSM 120

can be printed out.

As described above, in the prior art stationary coordinate system-based sensorless control using only the first estimator 510 of the present invention, for example, in the sensorless method based on the back EMF estimation using the stationary coordinate system voltage equation, the speed increases due to the characteristics of the back EMF observer. There is a disadvantage in that the phase delay increases as the frequency increases, and thus the position estimation error increases.

On the other hand, the sensorless method based on magnetic flux estimation using the stationary coordinate system voltage equation, which is another example of the prior art using only the first estimator 510 of the present invention, is higher than the bandwidth of HPF due to the characteristics of the magnetic flux estimator composed of a combination of an integrator and HPF. There is a disadvantage in that a position estimation error occurs due to a phase lead at a low speed.

10 is a block diagram illustrating a PMSM sensorless control apparatus using a back EMF estimator in a general synchronization coordinate system in the technical field of the present invention as a comparative example of the present invention.

The comparative example of FIG. 10 may be understood as a sensorless control device using only the second estimator 530 and the position/velocity detector 550 in the configuration of FIGS. 5 to 9 of the present invention.

In the comparative example shown in FIG. 10, that is, in the sensorless method based on the counter electromotive force estimation using the synchronous coordinate system voltage equation, the bandwidth of the PLL used for position/velocity estimation in the low speed region is limited, and the low speed driving performance is deteriorated. have.

,

)을 축 변환기(1038)가 추정된 DQ축에 대한 전압 및 전류 값(

,

)으로 변환하고, 역기전력 추정기(1032)는 추정된 DQ축을 기준으로 역기전력을 추정한다. 추정 과정은 앞에서 설명한 수학식 7 내지 수학식 9에 의하여 수행된다.In the comparative example of FIG. 10, the rotor winding voltage and current values (

,

) to the voltage and current values (

,

), and the back EMF estimator 1032 estimates the back EMF based on the estimated DQ axis. The estimation process is performed according to Equations 7 to 9 described above.

축)이고, PLL 처리기(1050)에 의하여 위치 오차를 반영하여 추정된 DQ축(

축)과 실제의 DQ축 간의 오차를 줄이는 것이 도 10의 비교례에서의 목표이다. 도 10의 비교례에서 상기 수학식 7 내지 수학식 9에서 제시된 수학적 모델의 특성 상 추정된 역기전력에 이미 위치 오차 정보가 반영되었다고 생각할 수 있다. 따라서 정지 좌표계 기반 방식의 종래 기술들에서 나타나는 위상 지연 등의 영향을 줄일 수 있다. 다만 앞에서 설명한 것처럼 도 10의 PLL 처리기(1050)에 도 4의 적분기(420)와 같은 구성을 사용하는 경우 위치 오차가 이미 반영된 상태에서 위치 오차가 계속 누적될 수 있다.The angle error calculator 1034 generates an angle error by performing an arctan operation on the back electromotive force, and the angle error (position error) is transmitted back to the axis converter 1038 by the PLL processor 1050 . At this time, the back EMF estimator 1032 uses the estimated DQ axis (not the actual DQ axis)

axis), and the DQ axis (

axis) and the actual DQ axis is a goal in the comparative example of FIG. 10 . In the comparative example of FIG. 10 , it can be considered that the position error information has already been reflected in the estimated back electromotive force due to the characteristics of the mathematical models presented in Equations 7 to 9 above. Accordingly, it is possible to reduce the effect of phase delay, etc., which appears in the prior art of the stationary coordinate system-based method. However, as described above, when the PLL processor 1050 of FIG. 10 uses the same configuration as the integrator 420 of FIG. 4 , the position error may be continuously accumulated while the position error is already reflected.

Referring again to the configuration of FIGS. 5 to 9 of the present invention, in the comparative example shown in FIG. 10 , information on position estimation is fed back from the PLL processor 1050 to the axis converter 1038 , whereas in the present invention, the first estimator There is a difference in that the position of the rotor estimated at 510 , that is, the first estimate value is transmitted to the axis converters 638 and 938 of the second estimator 530 .

At this time, in the present invention, the sensorless position estimation error due to the phase delay (or phase lead) that appears when estimating the back electromotive force (or magnetic flux) based on the stationary coordinate system voltage equation in the first estimator 510 is primarily estimated A method for compensating for a sensorless position estimation error is proposed using a physical law that is included in the back electromotive force estimated by the second estimator 530 from the voltage equation in the synchronous coordinate system based on the angle.

In the comparative example of FIG. 10 , since the PLL processor 1050 generally uses the integrator 420 as shown in FIG. 4 , there is a problem that the position error may be continuously accumulated while the position error is already reflected as described above. . 5 to 9 of the present invention, a means for separately estimating the location information is introduced as the first estimator 510 so that the location error is not continuously accumulated, and the first estimator 510 performs the first operation for the location information. By passing the estimated value to the second estimator 530, the second estimator 530 provides a reference value for calculating the position error, while blocking the position error within the mathematical model used by the second estimator 520 from continuously accumulating. do. Meanwhile, in the first estimator 510, a phase delay may occur during high-speed operation (back EMF) or a phase lead may occur at low speed/low frequency (magnetic flux) depending on whether the first physical quantity information to be estimated is back EMF or magnetic flux. As the first estimated value of 510 is passed through the mathematical model of the second estimator 530 and the second estimated value is generated by the second estimator 530, the problem of phase delay or phase lead can be solved.

The present invention is significantly different from the methods of the prior art that simply operate a plurality of sensorless control methods using voltage equations in different coordinate systems at the same time and selectively use a sensorless control method that is advantageous at a corresponding speed according to the driving speed. For example, as a simple combination of conventional techniques, a case in which a back EMF estimation method based on a stationary coordinate system voltage equation is used in a low speed region and a magnetic flux estimation method based on a stationary coordinate system voltage equation is used in a high speed region may be considered. Although these prior art combinations may bring their respective advantages, they cannot compensate for their respective disadvantages. In the combination of the prior art, the stationary coordinate system back EMF estimation method still has a problem in the high-speed region, and the stationary coordinate system magnetic flux estimation method still has a problem in the low-speed region.

As an example of another method of simply combining and applying the conventional sensorless control methods, one sensorless control method is used as the main method, and another There may be cases where one sensorless control method is used as an auxiliary method. In KR 10-1961106, a method of calculating the rotor position using the Matsui algorithm in a synchronous rotational coordinate system is used as the main sensorless control method, but a stationary coordinate system-based magnetic flux estimation method is used in parallel as an auxiliary means for detecting whether a step-out has occurred. apply Even in a parallel coupling method such as KR 10-1961106, the synchronous rotational coordinate system counter electromotive force estimation method and the stationary coordinate system magnetic flux estimation method operate independently of each other and then compare the calculated rotor angle/position, so the advantages and disadvantages of each are maintained. However, the disadvantages of each sensorless control technique are not cured by parallel combination as in KR 10-1961106.

On the other hand, according to the embodiments of the present invention, since the magnetic flux estimation (or counter electromotive force estimation) based on the stationary coordinate system voltage equation and the counter electromotive force estimation method based on the synchronous coordinate system voltage equation are combined and used in a hybrid form, each There are features that complement each other's shortcomings. As a result, according to the embodiments of the present invention, there is no need to selectively apply the sensorless control method according to the operation area, and it is possible to realize stable sensorless control performance while using a single sensorless control method over a wide operation area. have.

In the embodiments of the present invention, the synchronous coordinate system set when estimating the synchronous coordinate system-based back EMF is set based on the first estimated value for the angle of the rotor of the motor obtained based on the magnetic flux or the back EMF estimated in the stationary coordinate system, at this time Estimate the back electromotive force of the motor in the synchronous coordinate system, and use the counter electromotive force estimated in the synchronous coordinate system to generate position and speed information of the rotor in which the error included in the angle of the first estimated value is compensated. Although the concept and configuration of the conventional sensorless control schemes are used in these embodiments of the present invention, these configurations are complementary and organically combined, and in this process, unlike the conventional sensorless control scheme, a very wide operation It is possible to realize stable sensorless control performance in the field.

In addition, as can be seen by comparing the comparative example of FIG. 10 and the embodiments of FIGS. 5 to 9 , the embodiments of the present invention organically combine various sensorless control techniques of the prior art, but in this process the prior art sensorless control The technique is not applied as it is, but some changes are made to meet the purpose of the present invention, so that the configuration of the present invention is differentiated from the prior art.

11 is a diagram illustrating a waveform of a simulation result of PMSM sensorless control according to an embodiment of the present invention.

Referring to FIG. 11, in the first embodiment of FIG. 5, when the present invention is implemented based on magnetic flux estimation, the bandwidth of the PLL used for position/velocity estimation in a low-speed region can be set to be larger than that of other methods, , it is possible to secure better sensorless control performance in applications with large load fluctuations at low speeds (eg, the washing mode of a drum washing machine employing a DD motor). The waveform diagram of FIG. 11 shows the results of computer simulation using the washing load of the drum washing machine as a model for the sensorless control method proposed in the first embodiment of the present invention. Referring to FIG. 11 , in the case of the sensorless control method using only the conventional magnetic flux estimator, it can be seen that the estimated rotor position deviates significantly from the actual rotor position after 0.2 seconds. On the other hand, it can be seen that in the method proposed in the present invention, although there are some sections in which the position estimation error increases as the transient section is repeated, the overall sensorless position estimation error maintains a small value.

As described above, a sensorless control apparatus for an electric motor according to an embodiment of the present invention has been disclosed through FIGS. 1 to 11 . On the other hand, in the sensorless control method of the present invention, each functional element may be implemented as hardware by a processor, a controller, and/or distributed designed logic, but the functional elements performing the same function are loaded into the memory in the form of program instructions, and the processor, It may be called and executed by a controller, and/or distributed designed logic. This embodiment implements another embodiment of the present invention as a model-based sensorless control method of a permanent magnet motor (PMSM).

For example, the operation of the first estimator 510 and its sub-functional elements shown in FIG. 5 may be implemented in the form of program instructions and executed as a first estimation step executed by a processor, a controller, and/or distributed designed logic. have.

In addition, the operations of the second estimator 530 and its sub-functional elements shown in FIG. 5 may be implemented in the form of program instructions and executed as a second estimation step executed by a processor, a controller, and/or distributed designed logic.

In addition, the operation of the lower functional elements of the position/velocity detector 550 shown in FIG. 5 may be implemented in the form of a program instruction and executed as a position/velocity detection step executed by a processor, a controller, and/or distributed designed logic.

The operations of the sub-functional elements of the first estimator 510, the second estimator 530, and the position/velocity detector 550 shown in FIGS. 4 and 6 to 9 are implemented in the form of program instructions so that the processor, the controller, and/or distributed design logic, etc., and each sub-functional element may constitute a detailed step of the first estimation step, the second estimation step, or the position/velocity detection step, respectively, according to the coupling relationship thereof.

The sensorless control method of an electric motor according to an embodiment of the present invention may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

However, the present invention is not limited or limited by the examples. Like reference numerals in each figure indicate like elements. Length, height, size, width, etc. introduced in the embodiments and drawings of the present invention may be exaggerated to help understanding.

As described above, in the present invention, specific matters such as specific components, etc., and limited embodiments and drawings have been described, but these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , various modifications and variations are possible from these descriptions by those of ordinary skill in the art to which the present invention pertains.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and not only the claims to be described later, but also all those with equivalent or equivalent modifications to the claims will be said to belong to the scope of the spirit of the present invention. .

110: rotor position/speed estimator
510: first estimator
530: second estimator
550: position/velocity detector

Claims (12)

In a model-based sensorless control device using voltage and current supplied to a permanent magnet motor (PMSM),
a first estimator for estimating first physical quantity information describing the operation of the electric motor in a stationary coordinate system;
a second estimator for estimating second physical quantity information representing the counter electromotive force of the electric motor in a synchronous coordinate system based on a first estimated value for an angle of a rotor of the electric motor obtained based on the first physical quantity information; and
a position/speed detector for generating position and speed information of a rotor of the electric motor in which an error included in the angle of the first estimated value is compensated by using the second physical quantity information;
A sensorless control device of a permanent magnet motor comprising a. According to claim 1,
The first physical quantity information is a sensorless control device of a permanent magnet motor that is a magnetic flux of the motor. According to claim 1,
The first physical quantity information is a sensorless control device of a permanent magnet motor that is a counter electromotive force of the motor. 3. The method of claim 2,
The first estimator,
a magnetic flux estimator for estimating the magnetic flux of the electric motor as the first physical quantity information in the stationary coordinate system; and
a magnetic flux angle calculator for generating the first estimated value for the angle of the rotor of the electric motor based on the first physical quantity information;
A sensorless control device of a permanent magnet motor comprising a. 4. The method of claim 3,
The first estimator,
a first counter electromotive force estimator for estimating the back electromotive force of the electric motor as the first physical quantity information in the stationary coordinate system; and
a back electromotive force angle calculator for generating the first estimated value for the angle of the rotor of the electric motor based on the first physical quantity information;
A sensorless control device of a permanent magnet motor comprising a. The method of claim 1,
The second estimator is
a second counter electromotive force estimator for estimating the second physical quantity information of the electric motor in a synchronous coordinate system based on the first estimated value;
an angular velocity calculator for calculating the angular velocity of the rotor of the electric motor based on the first physical quantity information and transmitting the angular velocity to the second counter electromotive force estimator; and
an angle error calculator for calculating an error included in the angle of the first estimated value based on the angular velocity and the second physical quantity information;
A sensorless control device of a permanent magnet motor comprising a. 7. The method of claim 6,
The second estimator is
an axis converter that converts the voltage and current values of the motor in the stationary coordinate system into voltage and current values of the motor in the synchronous coordinate system and transmits them to the second counter electromotive force estimator;
further comprising,
The shaft converter
Setting an estimated synchronous coordinate system based on the estimated D-axis with respect to the actual D-axis of the rotor of the motor, and using the estimated synchronous coordinate system as the synchronous coordinate system for converting voltage and current values of the motor,
setting the estimated synchronization coordinate system based on the first estimated value for the angle of the rotor of the electric motor obtained from the first physical quantity information
Sensorless control device for permanent magnet motors. In a model-based sensorless control method using voltage and current supplied to a permanent magnet motor (PMSM),
a first estimation step of estimating first physical quantity information describing the operation of the electric motor in a stationary coordinate system;
a second estimation step of estimating second physical quantity information representing the counter electromotive force of the electric motor in a synchronous coordinate system based on a first estimated value for an angle of a rotor of the electric motor obtained based on the first physical quantity information; and
a position/speed detection step of generating position and speed information of a rotor of the electric motor in which an error included in the angle of the first estimated value is compensated by using the second physical quantity information;
A sensorless control method of a permanent magnet motor comprising a. 9. The method of claim 8,
The first estimation step is
a magnetic flux estimation step of estimating the magnetic flux of the electric motor as the first physical quantity information in the stationary coordinate system; and
a magnetic flux angle calculation step of generating the first estimated value for the angle of the rotor of the electric motor based on the first physical quantity information;
A sensorless control method of a permanent magnet motor comprising a. 9. The method of claim 8,
The first estimation step is
a first counter electromotive force estimating step of estimating the back electromotive force of the electric motor as the first physical quantity information in the stationary coordinate system; and
a counter electromotive force angle calculation step of generating the first estimate value for the angle of the rotor of the electric motor based on the first physical quantity information;
A sensorless control method of a permanent magnet motor comprising a. 9. The method of claim 8,
The second estimation step is
a second counter electromotive force estimating step of estimating the second physical quantity information of the electric motor in a synchronous coordinate system based on the first estimated value;
an angular velocity calculation step of calculating an angular velocity of a rotor of the electric motor based on the first physical quantity information and transferring the angular velocity to the second counter electromotive force estimating step; and
an angle error calculation step of calculating an error included in the angle of the first estimated value based on the angular velocity and the second physical quantity information;
A sensorless control method of a permanent magnet motor comprising a. 12. The method of claim 11,
The second estimation step is
an axis conversion step of converting the voltage and current values of the motor in the stationary coordinate system into voltage and current values of the motor in the synchronous coordinate system before the second counter electromotive force estimating step;
further comprising,
The axis transformation step is
Setting an estimated synchronous coordinate system based on the estimated D-axis with respect to the actual D-axis of the rotor of the motor, and using the estimated synchronous coordinate system as the synchronous coordinate system for converting voltage and current values of the motor,
setting the estimated synchronization coordinate system based on the first estimated value for the angle of the rotor of the electric motor obtained from the first physical quantity information
Sensorless control method of permanent magnet motor.

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