WO2019245112A1

WO2019245112A1 - Rotor structure for detecting position of motor

Info

Publication number: WO2019245112A1
Application number: PCT/KR2018/013205
Authority: WO
Inventors: 강동우; 설현수
Original assignee: 계명대학교 산학협력단
Priority date: 2018-06-20
Filing date: 2018-11-01
Publication date: 2019-12-26
Also published as: KR102038084B1

Abstract

According to a rotor structure for detecting a position of a motor proposed by the present invention, a rotor shape structure for detecting a position of a Brushless DC (BLDC) motor is implemented, wherein notches are configured to be arranged on the q-axes of the rotor and an auxiliary rotor, respectively. Therefore, the rotor structure can remove a cause of signal distortion, increase torque, and decrease torque ripple.

Description

Rotor structure for position detection of motor

The present invention relates to a rotor structure for detecting a position of an electric motor, and more particularly, to implement a rotor shape structure for detecting a position of a brushless DC (BLDC) motor, wherein the notch is formed on the q axis of the rotor and the auxiliary rotor. The arrangement relates to a rotor structure for detecting a position of an electric motor that can eliminate a signal distortion factor and reduce torque rise and torque ripple.

In general, a BLDC motor removes a brush that acts as a commutator in a DC motor and maintains the properties of the DC motor. The BLDC motor includes a stator made of a three-phase coil, a rotor made of a permanent magnet, and a position detecting device. The BLDC motor rotates the rotor by flowing a current to each phase of the stator side coil of the BLDC motor and causing a magnetic field to be generated by the current. At this time, the BLDC motor detects the strength of the magnetic field of the rotor, and the rotor continues in one direction by sequentially turning on / off switching elements for changing the direction of the current flowing in each phase of the coil according to the detected magnetic field. To rotate.

That is, the BLDC motor does not use a brush, but detects the position of the rotor performed by the brush through a Hall sensor using the magnetic field and strength of the rotor, and uses the detected signal to position the rotor of the BLDC motor. It generates a signal for position control to control the.

As such, the structure of the BLDC motor using the Hall sensor for detecting the position of the rotor can be largely divided into two types. The first method is to design the stacking length of the rotor a little higher than the stator. In this case, the three Hall sensors are electrically placed on the stator at 120-degree intervals to detect the position of the rotor. The second method is to apply the auxiliary rotor. In this case, the shape of the ring magnet or SPM (Surface Permanent Magnet) type is mainly used. Will be placed.

In addition, conventionally, when using the auxiliary rotor when detecting the position of the BLDC motor, it can be divided into two types according to the shape of the rotor. The first is to use a ring magnet or SPM type auxiliary rotor regardless of the shape of the rotor. The second case uses the same type as the shape of the rotor. If the shape of the rotor is an IPM (Interior Permanent Magnet) type, the rotor and the position detecting rotor have the same shape.

1 is a diagram showing a perspective view of a rotor structure having a conventional position detecting auxiliary rotor, and FIG. 1 (a) shows a structure of a rotor having a ring magnet type position detecting auxiliary rotor. The structure is shown, and FIG. 1 (b) has shown the structure of the rotor structure provided with the auxiliary rotor for position detection of IPM type. 2 is a view showing the waveform of the pore magnetic flux density of the conventional auxiliary rotor for IPM type position detection, Figure 3 is a view showing the Hall sensor waveform of the conventional rotor for the IPM type position detection.

With the conventional position detection rotor structure, a problem when using the IPM type is the occurrence of signal distortion due to leakage magnetic flux. That is, the problem caused by the leakage magnetic flux will cause the sensor to malfunction. The Hall sensor is a sensor whose output is '1' when a specific magnetic flux value is measured, and the distortion of the air gap magnetic flux density waveform (see FIG. 2) caused by the leakage magnetic flux causes distortion of the Hall sensor signal (see FIG. 3).

If the shape of the position detecting rotor is the same as that of the rotor as in the conventional art, the manufacturing process can be simplified and the cost can be reduced. However, when the shape of the rotor is IPM type, the signal distortion of the hall sensor is distorted. There was a problem that caused the phenomenon. Korean Unexamined Patent Publication No. 10-2010-0109693 has been disclosed as a prior art document.

The present invention has been proposed to solve the above problems of the conventionally proposed methods, and implements a rotor-shaped structure for detecting the position of a brushless DC (BLDC) motor, but the q-axis of the rotor and the auxiliary rotor It is an object of the present invention to provide a rotor structure for detecting the position of an electric motor by arranging each notch so as to eliminate a signal distortion factor and reduce torque rise and torque ripple.

In addition, the present invention is configured by inserting the notch into the q-axis of the auxiliary rotor and the rotor for detecting the position of the motor, the magnetic resistance of the q-axis increases, thereby controlling the magnetic resistance and the air gap magnetic flux through the torque ripple It is another object of the present invention to provide a rotor structure for detecting the position of an electric motor, which can reduce the signal distortion, and in particular the signal distortion phenomenon in the hall sensor can be eliminated.

In addition, the present invention, by configuring the auxiliary rotor and rotor for the position detection of the IPM type in the same shape, the cost reduction through the reduction in manufacturing process and cost reduction as well as the torque is increased compared to the conventional IPM type It is another object of the present invention to provide a rotor structure for detecting the position of an electric motor, which can achieve a remarkable effect of reducing torque ripple.

Rotor structure for detecting the position of the motor according to a feature of the present invention for achieving the above object,

Rotor structure for position detection of the motor,

A rotor in which a rotating shaft is press-fitted in the center and radially disposed with respect to the center of rotation and a plurality of permanent magnets are disposed in the rotor core having a rotation radius; And

It is characterized by including the auxiliary rotor which is press-fitted and fixed to the upper part of the rotary shaft press-fitted to the center of the rotor, and functions to detect the position of the electric motor.

Preferably, the rotor,

The plurality of permanent magnets may be embedded in an IPM (Interior Permanent Magnet) type.

More preferably, the rotor,

In order to reduce torque ripple and torque ripple of the electric motor, the notch may be inserted into the q-axis of the rotor core.

Even more preferably, the rotor,

The notch increases the magnetoresistance of the q-axis, thereby controlling the magnetoresistance and the air gap magnetic flux, thereby reducing the torque ripple.

Preferably, the auxiliary rotor,

In order to remove the signal distortion of the Hall sensor provided for the position detection of the motor may be configured to insert a notch (notch) in the q axis of the auxiliary rotor core.

More preferably, the auxiliary rotor,

It can be configured to have the same shape structure as the rotor.

More preferably, the auxiliary rotor,

Press-fit fixed to the upper portion of the rotary shaft indented in the center of the rotor, it may be configured to have a structure in which a plurality of auxiliary permanent magnets are disposed on the auxiliary rotor core having a radial radius is disposed radially based on the rotation center.

Even more preferably, the auxiliary rotor,

The plurality of auxiliary permanent magnets may be embedded in an IPM (Interior Permanent Magnet) type.

More preferably, the auxiliary rotor,

It is configured to have the same shape structure as the rotor, it is possible to reduce the manufacturing process and cost reduction.

More preferably, the auxiliary rotor,

It may be disposed at a position higher than the stator to enable position detection through three Hall sensors provided in the motor.

Even more preferably, the stator is

The three Hall sensors can be electrically arranged at 120 degree intervals to detect the position of the auxiliary rotor.

More preferably, the rotor structure,

The notch inserted into the rotor core of the rotor and the notch inserted into the auxiliary rotor core of the auxiliary rotor may be positioned in the same position.

Even more preferably, the rotor core,

Consisting of an integral laminated structure using an electrical steel sheet, the electrical steel sheet of the rotor core may be composed of a non-oriented silicon steel sheet material.

Even more preferably, the auxiliary rotor core,

Consisting of an integral laminated structure using an electrical steel sheet, the electrical steel sheet of the auxiliary rotor core may be made of a non-oriented silicon steel sheet material.

Even more preferably, the plurality of permanent magnets,

It can be composed of rare earth permanent magnets.

Even more preferably, the plurality of permanent magnets,

It is composed of a rare earth permanent magnet, but may be composed of neodymium (NdFeB) magnet material.

Even more preferably, the plurality of auxiliary permanent magnets,

It can be composed of rare earth permanent magnets.

Even more preferably, the plurality of auxiliary permanent magnets,

The rare earth rare earth permanent magnets are buried, but may be composed of neodymium (NdFeB) magnet material.

Even more preferably, the rotor structure is

It may be disposed and installed in the inner center of the stator fixedly installed in the motor housing of the motor.

Even more preferably, the stator is

It may be composed of a stator core in which a coil is wound around a cylindrical stator body.

Even more preferably, the rotor structure is

It is disposed at the inner center of the stator fixedly installed in the motor housing of the motor, and can be applied to a BLDC motor system that detects the position of the rotor using a hall sensor.

According to the rotor structure for detecting the position of the motor proposed by the present invention, while implementing a rotor-shaped structure for the position detection of the brushless DC (BLDC) motor, each notch ( By arranging Notch), it is possible to eliminate the signal distortion factor and reduce the torque rise and the torque ripple.

In addition, according to the present invention, by inserting the notch into the q-axis of the auxiliary rotor and the rotor for detecting the position of the motor, the magnetic resistance of the q-axis increases, thereby controlling the magnetic resistance and the air gap magnetic flux through the torque Ripple can be reduced, and in particular the signal distortion in the Hall sensor can be eliminated.

In addition, the present invention, by configuring the auxiliary rotor and rotor for the position detection of the IPM type in the same shape, the cost reduction through the reduction in manufacturing process and cost reduction as well as the torque is increased compared to the conventional IPM type In addition, a remarkable effect of reducing torque ripple can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the perspective view of the rotor structure provided with the conventional rotor for position detection.

Fig. 2 is a view showing waveforms of air gap magnetic flux density of a conventional rotor for IPM type position detection.

3 is a view showing a Hall sensor waveform of a conventional rotor for IPM type position detection.

4 is a diagram showing a perspective view of the rotor structure for detecting the position of the motor according to an embodiment of the present invention.

5 is a plan view showing the auxiliary rotation of the rotor structure for detecting the position of the motor according to an embodiment of the present invention.

FIG. 6 is a view showing a pore flux density waveform of an auxiliary rotor for IPM type position detection in a rotor structure for detecting a position of an electric motor according to an embodiment of the present invention; FIG.

FIG. 7 is a view illustrating a hall sensor waveform of an auxiliary rotor for detecting an IPM type position in a rotor structure for detecting a position of an electric motor according to an embodiment of the present invention. FIG.

8 is a diagram illustrating a comparison of torque waveforms of an IPM type rotor model and a conventional IPM type rotor model applied to a rotor structure for detecting a position of an electric motor according to an embodiment of the present invention.

100: rotor structure for detecting the position of the motor according to an embodiment of the present invention

110: rotor

111: axis of rotation

112: rotor core

113: permanent magnet

114: notch

120: auxiliary rotor

121: auxiliary rotor core

122: auxiliary permanent magnet

123: notch

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. However, in describing the preferred embodiment of the present invention in detail, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions.

In addition, in the specification, when a part is 'connected' to another part, it is not only 'directly connected' but also 'indirectly connected' with another element in between. Include. In addition, the term "comprising" a certain component means that the component may further include other components, except for the case where there is no contrary description.

4 is a diagram showing a perspective view of the rotor structure for detecting the position of the motor according to an embodiment of the present invention, Figure 5 is a secondary rotation of the rotor structure for detecting the position of the motor according to an embodiment of the present invention 6 is a view showing a planar configuration of FIG. 6 is a view showing a pore flux density waveform of an auxiliary rotor for IPM type position detection in a rotor position detecting rotor structure of an electric motor according to an embodiment of the present invention. 7 is a view showing a hall sensor waveform of the IPM type position detecting auxiliary rotor in the rotor structure for detecting the position of the motor according to an embodiment of the present invention, Figure 8 is a motor according to an embodiment of the present invention Fig. 1 shows the comparison of the torque waveforms of the IPM type rotor model and the conventional IPM type rotor model applied to the rotor structure for position detection. As shown in FIGS. 4 and 5, the rotor structure 100 for detecting the position of the electric motor according to an embodiment of the present invention includes a rotor 100 and an auxiliary rotor 120. Can be.

The rotor 110 is a configuration in which a plurality of permanent magnets 113 are disposed in the rotor core 112 having a rotation radius radially disposed with respect to the center of rotation and the rotary shaft 111 is pressed in the center. The rotor 110 may be a plurality of permanent magnets 113 is embedded in an IPM (Interior Permanent Magnet) type. Here, as shown in FIG. 4, the rotor 110 may be configured to insert the notch 114 into the q-axis of the rotor core 112 to increase torque and reduce torque ripple of the motor. . At this time, the rotor 110 increases the magnetic resistance of the q-axis through the notch 114, thereby controlling the magnetic resistance and the air gap magnetic flux to function to reduce the torque ripple.

In addition, the rotor core 112 of the rotor 110 is composed of an integral laminated structure using an electrical steel sheet, the electrical steel sheet of the rotor core 112 may be composed of a non-oriented silicon steel sheet material.

In addition, the plurality of permanent magnets 113 of the rotor 110 may be composed of a rare earth permanent magnet. Preferably, the plurality of permanent magnets 113 may be embedded with rare earth permanent magnets, but may be made of neodymium (NdFeB) magnet material.

The auxiliary rotor 120 is press-fitted and fixed to the upper portion of the rotary shaft 111 press-fitted to the center of the rotor 110, and is configured to function for position detection of the electric motor. As shown in FIGS. 4 and 5, the auxiliary rotor 120 is notched on the q-axis of the auxiliary rotor core 121 to eliminate signal distortion of the hall sensor provided for position detection of the motor. (Notch) 123 may be formed to insert the structure. Here, the auxiliary rotor 120 has a large magnetic resistance of the q-axis through the notch 123, thereby controlling the magnetic resistance and the air gap magnetic flux to function to reduce the torque ripple.

In addition, the auxiliary rotor 120 may be configured to have the same shape structure as the rotor 110, as shown in FIG. The auxiliary rotor 120 is press-fitted and fixed to the upper portion of the rotary shaft 111 press-fitted to the center of the rotor 110, radially disposed with respect to the center of rotation to the auxiliary rotor core 121 having a rotation radius It may be configured in a structure in which a plurality of auxiliary permanent magnets 122 are arranged.

In addition, the auxiliary rotor 120, like the plurality of permanent magnets 113 of the rotor 110 may be a plurality of auxiliary permanent magnets 122 are embedded in an IPM (Interior Permanent Magnet) type. Since the auxiliary rotor 120 is configured to have the same shape structure as the rotor 110, it is possible to reduce the manufacturing process and cost reduction.

In addition, the auxiliary rotor 120 is preferably disposed at a position higher than the stator (not shown) to enable the position detection through three Hall sensors (not shown) provided in the motor. At this time, the stator is a general configuration of the electric motor, it is possible to detect the position of the auxiliary rotor 120 by placing three Hall sensors electrically 120 degrees apart. In addition, the stator may be composed of a stator core in which a coil is wound around a cylindrical stator body. Here, the three Hall sensors and the stator correspond to the general configuration of the motor, so unnecessary description thereof will be omitted.

In addition, the auxiliary rotor core 121 of the auxiliary rotor 120 is composed of an integral laminated structure using an electrical steel sheet, the electrical steel sheet of the auxiliary rotor core 121 may be composed of a non-oriented silicon steel sheet material have.

In addition, the plurality of auxiliary permanent magnets 122 of the auxiliary rotor 120 may be composed of a rare earth permanent magnet. In this case, the plurality of auxiliary permanent magnets 122 may be buried as rare earth rare earth permanent magnets, but may be made of neodymium (NdFeB) magnet material.

In addition, as shown in FIG. 4, the rotor structure 100 includes a notch 114 inserted into the rotor core 112 of the rotor 110 and an auxiliary rotor core of the auxiliary rotor 120. The location of the notch 123 inserted into the 121 may be the same.

In addition, the rotor structure 100 is disposed in the inner center of the stator fixedly installed in the motor housing of the motor, is disposed in the inner center of the stator fixedly installed in the motor housing of the motor, It can be applied to BLDC motor system for detecting the position of the rotor. In other words, the rotor structure 100 may be implemented as a system in which a BLDC motor is used in a field such as a household washing machine, an air conditioner, and a vehicle electric appliance.

FIG. 6 illustrates a pore flux density waveform of an auxiliary rotor for detecting an IPM type in a rotor structure for detecting a position of an electric motor according to an embodiment of the present invention, and FIG. 7 illustrates an electric motor according to an embodiment of the present invention. In the position detecting rotor structure, the hall sensor waveform of the IPM type position detecting auxiliary rotor is shown. That is, as shown in Figures 6 and 7, implement a rotor-shaped structure for the position detection of the brushless DC (BLDC) motor of the present invention, each notch (notch) on the q-axis of the rotor and the auxiliary rotor By arranging), it can be seen that the waveform of the pore magnetic flux density due to the leakage magnetic flux and the distortion of the measured signal of the Hall sensor are eliminated.

8 illustrates a comparison of torque waveforms of an IPM type rotor model and a conventional IPM type rotor model applied to a rotor structure for detecting a position of an electric motor according to an embodiment of the present invention.

In addition, the results of comparing the rotor structure to which the improved IPM type model for detecting the position of the motor according to an embodiment of the present invention and the conventional IPM type model by finite element analysis are shown in Table 1 below.

Table 1

That is, the rotor structure according to the present invention can be seen that the effect of increasing the torque, the torque ripple is reduced than the conventional IPM type model can be seen.

As described above, the rotor structure for detecting the position of the motor according to an embodiment of the present invention, while implementing a rotor shape structure for detecting the position of the brushless DC (BLDC) motor, q of the rotor and the auxiliary rotor By arranging each notch on the shaft, it is possible to eliminate the signal distortion factor and to reduce the torque rise and the torque ripple, and also the q of the auxiliary rotor and rotor for position detection of the motor. By inserting the notch into the shaft and arranging it, the magnetoresistance of the q axis is increased, and the torque ripple can be reduced by controlling the magnetoresistance and the air gap magnetic flux. It becomes possible. In particular, by configuring the auxiliary rotor and rotor for the position detection of the IPM type in the same shape, the cost reduction through the reduction in manufacturing process and cost reduction, as well as the torque is increased compared to the conventional IPM type, torque ripple It is possible to obtain a noticeable effect of decreasing.

The present invention described above may be variously modified or applied by those skilled in the art, and the scope of the technical idea according to the present invention should be defined by the following claims.

Claims

As the rotor structure 100 for detecting the position of an electric motor,

A rotor 110 in which a rotating shaft 111 is press-fitted in the center and radially disposed with respect to the center of rotation, and a plurality of permanent magnets 113 are disposed in the rotor core 112 having a rotation radius; And

An auxiliary rotor 120, which is press-fitted and fixed to an upper portion of the rotary shaft 111 press-fitted to the center of the rotor 110, serves to detect the position of the motor. Electronic structure.
The method of claim 1, wherein the rotor 110,

The plurality of permanent magnets 113 is embedded in an IPM (Interior Permanent Magnet) type, characterized in that the rotor structure for detecting the position of the motor.
The method of claim 2, wherein the rotor 110,

The rotor structure for detecting the position of the motor, characterized in that it is configured to insert the notch 114 in the q-axis of the rotor core 112 to increase the torque of the motor and reduce the torque ripple.
The method of claim 3, wherein the rotor 110,

The notch 114 increases the magnetoresistance of the q-axis, thereby controlling the magnetic resistance and the air gap magnetic flux to reduce the torque ripple, characterized in that the rotor structure for detecting the position of the motor.
The auxiliary rotor 120 according to any one of claims 1 to 4,

The motor is characterized in that it is configured to insert a notch (123) in the q-axis of the auxiliary rotor core 121 to remove the signal distortion of the Hall sensor provided for the position detection of the motor, Rotor structure for position detection.
The method of claim 5, wherein the auxiliary rotor 120,

The magnetic resistance of the q-axis is increased through the notch 123, thereby controlling the magnetic resistance and the air gap magnetic flux to reduce the torque ripple, the rotor structure for detecting the position of the motor.
The method of claim 5, wherein the auxiliary rotor 120,

Rotor structure for detecting the position of the motor, characterized in that it has the same shape structure as the rotor (110).
The method of claim 5, wherein the auxiliary rotor 120,

A plurality of auxiliary permanent magnets 122 are fixed to the upper part of the rotating shaft 111 press-fitted to the center of the rotor 110, and are radially disposed with respect to the center of rotation, to the auxiliary rotor core 121 having a rotation radius. Rotor structure for detecting the position of the electric motor, characterized by comprising a structure arranged).
The method of claim 8, wherein the auxiliary rotor 120,

The plurality of auxiliary permanent magnets 122 is embedded in an IPM (Interior Permanent Magnet) type, characterized in that the rotor structure for detecting the position of the motor.
The method of claim 5, wherein the auxiliary rotor,

Rotor structure for detecting the position of the electric motor, characterized in that configured to have the same shape structure as the rotor, to reduce the manufacturing process and cost reduction.
The method of claim 5, wherein the auxiliary rotor 120,

The rotor structure for detecting the position of the motor, characterized in that disposed in a position higher than the stator to enable the position detection through three Hall sensors provided in the motor.
The method of claim 11, wherein the stator,

A rotor structure for detecting the position of an electric motor, characterized in that the three Hall sensors are electrically arranged at intervals of 120 degrees to detect the position of the auxiliary rotor (120).
The method of claim 5, wherein the rotor structure 100,

The notch 114 inserted into the rotor core 112 of the rotor 110 and the notch 123 inserted into the auxiliary rotor core 121 of the auxiliary rotor 120 have the same position. Rotor structure for detecting the position of the electric motor, characterized in that positioned to be.
The method of claim 13, wherein the rotor core 112,

Rotor structure for detecting the position of the electric motor, characterized in that the electric steel sheet of the rotor core 112 is composed of an integrally laminated structure using an electric steel sheet, characterized in that the non-oriented silicon steel sheet material.
The method of claim 13, wherein the auxiliary rotor core 121,

Rotor structure for detecting the position of the electric motor, characterized in that it is composed of an integral laminated structure using an electrical steel sheet, wherein the electrical steel sheet of the auxiliary rotor core 121 is made of a non-oriented silicon steel sheet material.
The method of claim 13, wherein the plurality of permanent magnets 113,

A rotor structure for detecting the position of an electric motor, characterized by comprising a rare earth permanent magnet.
The method of claim 16, wherein the plurality of permanent magnets 113,

Rotor structure for detecting the position of the electric motor, characterized in that made of a rare earth permanent magnet buried, consisting of a neodymium (NdFeB) magnet material.
The method of claim 13, wherein the plurality of auxiliary permanent magnets 122,

A rotor structure for detecting the position of an electric motor, characterized by comprising a rare earth permanent magnet.
The method of claim 18, wherein the plurality of auxiliary permanent magnets 122,

A rotor structure for detecting the position of an electric motor, wherein the rare earth rare earth permanent magnet is buried and made of a neodymium (NdFeB) magnet material.
The method of claim 13, wherein the rotor structure 100,

The rotor structure for detecting the position of the electric motor, characterized in that disposed in the inner center of the stator fixedly installed in the motor housing of the electric motor.
The method of claim 20, wherein the stator,

A rotor structure for detecting a position of an electric motor, characterized in that the stator core is wound around a cylindrical stator body.
The method of claim 21, wherein the rotor structure 100,

A rotor structure for position detection of an electric motor, characterized in that it is disposed in an inner center of a stator fixedly installed in a motor housing of an electric motor, and is applied to a BLDC motor system that detects the position of a rotor using a hall sensor.