KR102504872B1 - Double air gap Surface Permanent Magnet Synchronous Motor - Google Patents

Abstract

The present invention relates to a dual air-gap type surface permanent magnet synchronous motor, and more particularly, to have high efficiency and high power density satisfying the IEC international efficiency class IE5 while improving torque performance by implementing a double structure of a rotor and a stator. It relates to a double-gap type surface permanent magnet synchronous motor.
A dual air gap type surface permanent magnet synchronous motor according to an embodiment of the present invention includes a first stator in which a first protrusion is formed along a first inner circumferential surface; a first rotor having a first outer circumferential surface facing the first inner circumferential surface; a first permanent magnet arranged along the first outer circumferential surface; a second rotor integrally connected to the first rotor while corresponding inwardly to have a second inner circumferential surface thereof; a second permanent magnet arranged along the second inner circumferential surface; and a second stator in which a second protrusion is formed along a second outer circumferential surface formed to face the second inner circumferential surface, wherein a first air gap of a predetermined space is formed between the first stator and the first rotor, A second air gap of a predetermined space is formed between the second stator and the second rotor, the N poles and the S poles of the first permanent magnet are alternately arranged at equal intervals along the first outer circumferential surface, and the second permanent magnet is N poles and S poles are alternately arranged at equal intervals along the second inner circumferential surface and are arranged in opposite polarity to the first permanent magnet, the first protrusions are formed in the same number as the second protrusions, and the first permanent magnets are formed in the same number. The same number of magnets as the second permanent magnets is formed but smaller than the number of the first protrusions.

Description

Double air gap surface permanent magnet synchronous motor

The present invention relates to a dual air-gap type surface permanent magnet synchronous motor, and more particularly, by realizing a rotor and a stator structure as a pair, which improves torque performance and achieves high efficiency and high power density that satisfy the IEC international efficiency class IE5. It relates to a double-gap type surface permanent magnet synchronous motor for having

In general, a motor is a device that converts electrical energy into mechanical energy to obtain rotational force, and is widely used in household electronic products as well as industrial devices, and is largely divided into DC motors and AC motors.

That is, as production processes are automated and highly precise to improve productivity, AC/DC motors are widely used in various industries.

Surface Permanent [Multi-phase] Synchronous Motor (SPMSM) consists of a rotor with a permanent magnet and a stator with an armature wound around a core. ) is classified as a BLDC (brushless direct current) motor if the shape of the back electromotive force generated while rotating is SPMSM if the shape is a sine wave, and if it is a square wave.

In addition, the motor includes an Interior Permanent Magnet (IPM) motor in which permanent magnets are embedded in the rotor core according to the arrangement of permanent magnets in the rotor, and permanent magnets are arranged on the surface of the rotor core. It is divided into Surface Permanent Magnet (SPM) motors.

A conventional surface-attached magnet type motor will be described with reference to the accompanying drawings.

1 is a plan view showing a surface-attached magnet type motor according to the prior art.

As shown, in the conventional surface-attached magnet type motor 10, a rotor 13 is installed so as to be rotatable by a shaft 14 with an air gap inside the stator 12 on which a coil (not shown) is wound. , A plurality of permanent magnets 15 are arranged and fixed along the outer circumferential surface of the rotor 13.

In the stator 12, a plurality of teeth 12b are protruded at regular intervals along the inner circumferential surface of the yoke part 12a having a circular ring shape, and a coil (not shown) is wound for each tooth 12b to generate a motor 10 is fixed to the housing (not shown) of

The rotor 13 is manufactured by stacking a plurality of silicon steel plates, and a shaft hole 13a is formed in the center so that the shaft 14 penetrates and is fixed, and a magnet mounting groove 13b is formed along the circumference of the outer circumferential surface. , Permanent magnets 15 are fixed by press fitting in each magnet mounting groove 13b.

When AC power is applied to the coil (not shown) of the conventional surface-attached magnet type motor 10, magnetic flux is generated in a direction perpendicular to the shaft 14 to rotate, and this rotating magnetic flux is generated on the surface of the rotor 13. The rotor 13 is rotated by generating a torque in the rotor 13 by the magnetic flux of the permanent magnet 15 located on the .

On the other hand, as climate change due to excessive emission of greenhouse gases is on the rise, the paradigm of energy policy is rapidly shifting to energy demand management such as energy saving and improvement of use efficiency to reduce greenhouse gas emissions.

Motors (electric motors) account for more than 54% of total power consumption.

As the core technology of motors (electric motors) develops, performance improvements such as miniaturization, light weight, low noise, low vibration, and high efficiency of motors are steadily being made. are constantly being requested.

2 shows an IEC (International Electro-technical Commission) international efficiency rating, and a surface-attached magnet type motor that can satisfy the IE5 rating by improving the conventional technology is desperately needed.

Korean Patent Registration No. 10-1332523, Title of Invention "Electric motor with a structure that bisects the permanent magnet array of the rotor" (Announcement date 2013.11.22.)

The present invention was created due to the above needs, and a double air gap type surface permanent to have high efficiency and high power density that satisfies the IEC international efficiency class IE5 while improving torque performance by implementing a double structure of a rotor and a stator. Its purpose is to provide a magnet synchronous motor.

In order to achieve the above object, a dual air gap type surface permanent magnet synchronous motor according to an embodiment of the present invention includes a first stator in which a first protrusion is formed along a first inner circumferential surface; a first rotor having a first outer circumferential surface facing the first inner circumferential surface; a first permanent magnet arranged along the first outer circumferential surface; a second rotor integrally connected to the first rotor while corresponding inwardly to have a second inner circumferential surface thereof; a second permanent magnet arranged along the second inner circumferential surface; And a second stator formed with a second protrusion along a second outer circumferential surface formed to face the second inner circumferential surface;

A first air gap of a predetermined space is formed between the first stator and the first rotor, a second air gap of a predetermined space is formed between the second stator and the second rotor, and the first permanent magnet is 1 N poles and S poles are alternately arranged at equal intervals along the outer circumferential surface, and N poles and S poles of the second permanent magnet are alternately arranged at equal intervals along the second inner circumferential surface, but have opposite polarity to the first permanent magnet. The first protrusions are formed in the same number as the second protrusions, and the first permanent magnets are formed in the same number as the second permanent magnets, but are smaller than the number of the first protrusions.
Another embodiment of the present invention, a double-gap type surface permanent magnet synchronous motor
a first stator in which a T-shaped first protrusion is formed along a first inner circumferential surface;
a first rotor having a first outer circumferential surface facing the first inner circumferential surface;
a first permanent magnet arranged along the first outer circumferential surface;
a second rotor integrally connected to the first rotor while corresponding inwardly to have a second inner circumferential surface thereof;
a second permanent magnet arranged along the second inner circumferential surface;
a second stator having a T-shaped second protrusion formed along a second outer circumferential surface formed to face the second inner circumferential surface;
a barrier rib portion formed at a boundary between the first rotor and the second rotor;
a first sleeve part made of metal that surrounds the outer periphery of the first permanent magnet in a hollow cylindrical shape with front and rear openings and prevents and protects the first permanent magnet from coming off;
a second sleeve part made of a metal material having a hollow cylindrical shape with front and rear openings, which surrounds and supports the inside of the second permanent magnet to prevent and protect the second permanent magnet from falling out;
a first control device controlling a first winding wound around the first protrusion; and
A second control device for controlling the second winding wound around the second protrusion; includes,
A first air gap having a gap of 0.8 ± 0.1 mm is formed between the first stator and the first rotor,
A second air gap having an air gap of 0.8 ± 0.1 mm is formed between the second stator and the second rotor,
In the first permanent magnet, N poles and S poles are alternately arranged at equal intervals along the first outer circumferential surface,
In the second permanent magnet, N poles and S poles are alternately arranged at equal intervals along the second inner circumferential surface, but are arranged in opposite polarities to those of the first permanent magnet;
The first protrusion is 24, which is the same number as the second protrusion,
The number of the first permanent magnets is equal to that of the second permanent magnets, but is 20 smaller than the number of the first protrusions.
When one of the first and second control devices fails, the other controls rotation of the first and second rotors integrally formed,
The barrier rib portion made of a non-magnetic material blocks mutual magnetic flux generated from the first and second permanent magnets,
The first and second rotors 120 and 140 are electrical steel sheets each having a thickness of 0.20±0.05 mm, density of 7.65±0.1 kg/cm2, core loss of 15.0 W/kg or less, magnetic flux density of 1.62 or more, and space factor. Characterized in that it is 93% or more.

According to the present invention, since it has a double-gap structure, it has an advantage of having high power density and torque.

In addition, there is an advantage in that cogging torque can be lowered than before due to the double-gap structure.

In addition, there is an advantage of increasing efficiency by improving the material of the double-gap structure under the same conditions.

1 is a view showing a surface-attached magnet type motor according to the prior art.
2 is a diagram showing an IEC (International Electrotechnical Commission) international efficiency class.
3 is an exemplary cross-sectional view showing a conventional SPMSM and a proposed double-gap type SPMSM.
4 is a graph showing the counter electromotive force of the conventional SPMSM and the proposed double-gap type SPMSM.
5 is a graph showing the cogging torque of the conventional SPMSM and the proposed double-gap type SPMSM.
6 is a graph showing the core loss (iron loss) of the conventional SPMSM and the proposed double-gap type SPMSM.
7 is a graph showing the magnetic flux density of the conventional SPMSM and the proposed double-gap type SPMSM.
8 is a graph showing the permanent magnet loss of the conventional SPMSM and the proposed double-gap type SPMSM.
9 is a graph showing the torque of the conventional SPMSM and the proposed double-gap type SPMSM.
10 is a diagram showing the specifications of a conventional SPMSM (I).
11 is a graph showing the results of conventional SPMSM (I).
12 is a diagram showing a specification of a conventional SPMSM (II).
13 is a graph showing the results of conventional SPMSM (II).
12 is a diagram showing specifications of conventional SPMSMs (II, III).
13 is a graph showing the results of conventional SPMSM (II).
14 is a graph showing the results of conventional SPMSM (III).
15 is a diagram showing the specifications of the proposed double-gap type SPMSM (IV).
16 is a graph showing the results of the proposed double-pore type SPMSM (IV).
17 is a diagram showing the specifications of the proposed double-gap type SPMSM (V).
18 is a graph showing the results of the proposed double-pore type SPMSM (V).
19 is an exemplary cross-sectional view showing a double-gap type SPMSM according to an embodiment of the present invention.
FIG. 20 is an enlarged view of part “Q” in FIG. 19 .
21 is an exemplary longitudinal cross-sectional view showing a double-gap type SPMSM according to an embodiment of the present invention.
22 is a diagram showing a magnetic flux direction for explaining a double-gap type SPMSM according to an embodiment of the present invention.
23 is a diagram showing the winding direction of illustratively A phase among three phases for explaining a double-gap type SPMSM according to an embodiment of the present invention.
24 and 25 are circuit diagrams for explaining a double-gap SPMSM according to an embodiment of the present invention.
26 is an exemplary view showing a partition wall of a double-gap type SPMSM according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

The terminology used herein is only for referring to specific embodiments and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. As used herein, the meaning of "comprising" specifies specific characteristics, regions, integers, steps, operations, elements, and/or components, and other specific characteristics, regions, integers, steps, operations, elements, elements, and/or groups. does not exclude the presence or addition of

Although not defined differently, all terms including technical terms and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with related technical literature and currently disclosed content, and are not interpreted in ideal or very formal meanings unless defined.

Embodiments of the present invention described with reference to the drawings specifically represent ideal embodiments of the present invention. As a result, various modifications of the illustrations are expected, for example, modifications of manufacturing methods and/or specifications. Therefore, the embodiment is not limited to the specific shape of the illustrated area, and includes, for example, modification of the shape by manufacturing. Regions shown or described as flat may have generally straddling and/or non-linear characteristics.

Also, parts shown as having sharp angles may be rounded. Accordingly, the regions shown in the drawings are only approximate in nature and their shapes are not intended to depict the exact shape of the region, nor are they intended to narrow the scope of the present invention.

It is advised that the drawings are schematic and not drawn to scale. Relative dimensions and proportions of parts in the drawings are shown exaggerated or reduced in size for clarity and convenience in the drawings, and any dimensions are illustrative only and not limiting. In addition, the same reference numerals appearing in two or more drawings of the same structure, element or part are used to indicate corresponding or similar features in different embodiments.

The present invention meets the IEC (International Electro-technical Commission) International Efficiency Class IE5, as the efficiency improvement of motors (motors), which account for more than 54% of power consumption, is continuously required as an effective means of reducing greenhouse gases. It is to propose a double air gap surface permanent magnet synchronous motor (SPMSM) design with high efficiency and high power density.

As shown in (a) of FIG. 3, a conventional Surface Permanent Magnet Synchronous Motor (SPMSM) has an external or internal rotor and has an external or internal rotational structure.

The structure proposed by the present invention is a double-gap structure using a rotor yoke as shown in (b) of FIG. have

The conventional structure and the proposed structure of the present invention were analyzed through FEM (Finite Elements Mehod), and the results were compared as follows.

1. Introduction

As climate change due to excessive emission of greenhouse gases has emerged as a serious problem, the paradigm of energy policy is rapidly shifting to energy demand management such as energy saving and improvement of use efficiency to reduce greenhouse gas emissions.

Motors (electric motors) account for more than 54% of total power consumption.

As the core technology of motors (electric motors) develops, performance improvements such as miniaturization, light weight, low noise, low vibration, and high efficiency of motors (motors) are steadily being made. Efficiency improvements are continuously required.

2 shows the IEC (International Electro-technical Commission) international efficiency class, and the present invention is proposed by designing a double air surface permanent magnet synchronous motor (SPMSM) to satisfy the IE5 class.

According to the present invention, the efficiency and power density of the conventional and proposed structures were analyzed based on FEM, and their performances were compared.

2. Body

2.1 Conventional and Proposed SPMSM's Structure and Characteristics Analysis

In the case of the conventional and proposed SPMSM, the outer diameter and stacking length of the stator are the same, and the detailed design structures of each are shown in Table 1.

Parameter Value Unit Number of stator slots 24 slot Number of poles 20 pole Stator outer diameter 200 mm Shaft outer diameter 20 mm Air-gap 0.8 mm PM height 4 mm Stack length 15 mm Number of turns per phase 16 turn Number of parallel paths 2 path Number of parallel wires
(strands in hand) 10 turn

3 shows the structure of a conventional and proposed 24 slot, 20 pole SPMSM.

In the case of materials of the conventional and proposed structures, POSCO's 35PN380 was applied and compared.

In addition, in the case of the proposed structure, 20PN1500 was additionally applied, and according to the material, the characteristics of 35PN380 of the conventional SPMSM and 35PN380 and 20PN1500 of the proposed SPMSM were analyzed and the performance was compared.

For reference, 35PN380 is a non-oriented electrical steel sheet produced by a company (POSCO). It has a thickness of 0.35±0.05mm, a density of 7.65±0.1kg/cm ² , a core loss of 3.80W/kg or less, a magnetic flux density of 1.62 or more, and an area ratio of 95% or more. As such, it has standard dimensions and magnetic properties.

In addition, 20PN1500 is a non-oriented electrical steel sheet produced by a company (POSCO), with a thickness of 0.20±0.05mm, a density of 7.65±0.1kg/cm ² , a core loss of 15.0W/kg or less, a magnetic flux density of 1.62 or more, and an area ratio of 93% or more. , standard dimensions, and magnetic properties.

Figure 4 is a diagram showing the counter electromotive force of the conventional and proposed SPMSM, the maximum voltage of the conventional SPMSM is 12.01 [V], the maximum voltage of 35PN380 of the proposed SPMSM is 20 [V], and the maximum voltage of 20PN1500 is 20.32 [V] .

Figure 5 shows the cogging torque of the conventional and proposed SPMSM.

In the case of the conventional SPMSM, the cogging torque is 145.68 [mNm], and in the case of the SPMSM proposed by the present invention, it is 102.37 [mNm] when the material is 35PN380 and 93.4 [mNm] when the material is 20PN1500.

Compared to the conventional case, the cogging torque of the proposed SPMSM with material 35PN380 was reduced by 29.7% compared to the conventional SPMSM, and in the case of SPMSM with material 20PN1500, the cogging torque was reduced by 35.9%.

Figure 6 shows the iron loss of the conventional and proposed SPMSM.

In the case of the conventional SPMSM, the core loss is 51.52 [W], and in the case of the material 35PN380 of the SPMSM proposed by the present invention, it is 91.4 [W], and in the case of 20PN1500, it is 67.8 [W].

Core loss (core loss) increased by 43.6% in the case of 35PN380, the material of the proposed SPMSM, and 24.01% in the case of 20PN1500, compared to the conventional SPMSM.

As shown in FIG. 7, this is due to the high magnetic flux density saturation of the iron core due to the winding [Fig. 7 (b), (c)] in which the core loss (iron loss) is increased compared to the conventional SPMSM [Fig. is considered to have increased.

Figure 8 shows the permanent magnet loss of the conventional and proposed SPMSM.

Conventional SPMSM has a permanent magnet loss of 9.14 [W], 35PN380 of the proposed SPMSM has 14.4 [W], and 20PN1500 has 17.78 [W].

It is judged that the loss of the permanent magnet in the proposed SPMSM is increased due to the permanent magnet increased by 1.7 times compared to the conventional SPMSM.

In the proposed SPMSM, the permanent magnet loss of 20PN1500 was higher than that of 35PN380.

This is the result of the increase in the burden of the permanent magnet due to the low saturation level of the magnetic flux density of the iron core.

Figure 9 shows the rated torque (Torque) of the conventional and proposed SPMSM.

The rated torque of the conventional SPMSM is 4.42 [Nm].

Compared to the conventional SPMSM, the rated torque of the material 35PN380 of the proposed SPMSM increased by 37% to 7.02Nm, and the rated torque of the material 20PN1500 increased by 36.67% to 6.98Nm.

Table 2 below shows a performance comparison table of the conventional and proposed SPMSM.

Parameter Conventional
( 35PN380 ) Proposed
( 35PN380 ) Proposed
( 20PN1500 ) Stator current frequency, Hz 500 ← ← Rotor speed, rpm 3,000 ← ← Electromagnetic torque, Nm 4.42 7.02 6.98 Output power, W 1301.96 2058.35 2066.24 Input, power, W 1413.33 2249.65 2237.08 Efficiency, % 92.12 91.45 94.23 Wingding losses, W 24.7 44.25 44.25 Core losses, W 51.52 91.4 67.8 Losses in PMs, W 9.14 14.4 17.78 Mechanical losses, W 25.96 41.24 41.01 Stator current density, A/mm² 4.818 9.636 9.636 Mass of Cu, kg 0.4421 0.7032 0.7032 Mass of Fe, kg 0.1958 4.2376 4.2376 Mass of PM, kg 0.1958 0.4945 0.4945 Total mass, kg 4.4036 5.4353 5.4353 Power density, kW/kg 0.2956 0.3787 0.3801

In the conventional case, iron loss is 51.52 [W], permanent magnet loss is 9.14 [W], and mechanical loss is 25.96 [W], which is lower than the proposed structure, while power density is 0.2956 kW/kg, which is lower than the proposed structure. get

In the case of 35PN380, the material of the proposed SPMSM, the power density is 0.3801kW/kg, which is higher than the conventional one, but the iron loss due to the double stator structure is 91.4W, the permanent magnet loss is 14.4W, and the mechanical loss is 41.24W. With W, the efficiency is 91.45%, slightly lower than the conventional SPMSM by 0.72%, but similar efficiencies are obtained.

In the case of 20PN1500, the material of the proposed SPMSM, the core loss is 67.8%, which is greater than the conventional SPMSM, but the same output as 35PN380 is 2066.24W, which is 37% higher than the conventional SPMSM.

In addition, the efficiency of the proposed SPMSM material 20PN1500 increased by 2.23% to 94.23%, and the power density increased by 22.23% to 0.3801kW/kg.

Then, more specifically, as shown in FIG. 10, the internal type [conventional SPMSM (I)] composed of a rotor facing the inner circumferential surface of the stator and having a permanent magnet is as follows.

SPMSM (Ⅰ) Parameter Value Stator current frequency, Hz 500 Rotor speed, rpm 3,000 Shaft torque, Nm 4.14 Electromagnetic torque, Nm 4.42 Shaft power (Output Power), W 1301.96
Input electric power, W (2π×(3000/60)×4.42)+(50×50×0.0033×3) 1413.33
Efficiency, % (1301.96/1413.33)×100 92.12
Winding losses, W (50×50×0.0033×3) 24.75 Core losses, W 51.52 Losses in PMs, W 9.14 Mechanical losses, W 25.96 Stator current, A rms 50
Stator current density, A/mm ² (50/2)/(0.4064×0.4064×3.14)×10=4.818 4.818 Mass of Cu, kg 0.4421
Mass of Fe, kg (Stator_Fe(1.7886)+Rotor_Fe(1.9771)) 2.0937 Mass of PM, kg 0.1958 Total mass (Eim components), kg 4.4036
Power density, kW/kg (1.30196/4.4036) 0.2956

10 shows the structure of a conventional SPMSM (I) having 24 slots and 20 poles.

In addition, the material of the conventional SPMSM (I) is 35PN380.

For reference, 35PN380 is a non-oriented electrical steel sheet produced by a company (POSCO). It has a thickness of 0.35mm, density of 7.65kg/cm ² , core loss of 3.80W/kg or less, magnetic flux density of 1.62 or more, and area coverage of 95% or more. Standard dimensions , has magnetic properties, etc.

11 shows Back EMF, core loss, permanent magnet loss, and rated torque of the conventional SPMSM (I).

In addition, the conventional SPMSM (Ⅰ) has a counter electromotive force of 12.01 [V] at the maximum voltage, an iron loss of 51.52 [W], a permanent magnet loss of 9.14 [W], a cogging torque of 145.68 [mNm], etc., and a rated torque of 4.42 [Nm].

In addition, the conventional SPMSM (I) produced similar or lower results in the material 20PN1500.

Next, as shown in FIG. 12, among conventional SPMSMs, an external type [conventional SPMSM (II)] composed of a rotor facing the outer circumferential surface of the stator and having permanent magnets is as follows.

The conventional SPMSM (II) is formed in the direction in which the windings come out, that is, in the direction in which torque collision occurs.

SPMSM (Ⅱ) Parameter Value Stator current frequency, Hz 500 Rotor speed, rpm 3,000 Shaft torque, Nm 5.27 Electromagnetic torque, Nm 5.69 Shaft power (output power), W 1656.49
Input electric power, W (2π×(3000/60)×5.69)+(50×50×0.0026×3) 1,807.06
Efficiency, % (1,656.49/1,807.06)×100% 91.66
Winding losses, W (50×50×0.0026)×3 19.5 Core losses, W 77.78 Losses in PMs, W 19.87 Mechanical losses, W 33.42 Stator current, A rms 50
Stator current density, A/mm ² (50/2)/(0.4064×0.4064×3.14)×10=4.818 4.818 Mass of Cu, kg 0.2611 Mass of Fe, kg (Stator_Fe(1.6047)+Rotor_Fe(0.5392)) 2.1439 Mass of PM, kg 0.2987 Total mass (Eim components), kg 2.7037
Power density, kW/kg (1.65649/2.7037) 0.6126

12 shows the structure of a conventional SPMSM (II) having 24 slots and 20 poles.

In addition, the material of the conventional SPMSM (II) is 35PN380.

13 shows Back EMF, core loss, permanent magnet loss, and rated torque of the conventional SPMSM (II).

In addition, the conventional SPMSM (II) has a maximum voltage of 17.01 [V] in counter-electromotive force, 77.78 [W] in iron loss, 19.87 [W] in permanent magnet loss, etc., and a rated torque of 5.69 [Nm], but actually collides with magnetic flux. This occurs and cancels out.

In addition, the conventional SPMSM (II) produced similar or lower results in the material 20PN1500.

Next, among conventional SPMSMs, an external type [conventional SPMSM (III)] composed of a rotor facing the outer circumferential surface of the stator and having permanent magnets is as follows.

The conventional SPMSM (III) is formed in a winding direction.

SPMSM (Ⅲ) Parameter Value Stator current frequency, Hz 500 Rotor speed, rpm 3,000 Shaft torque, Nm 2.6 Electromagnetic torque, Nm 2.73 Shaft power (output power), W 817.75
Input electric power, W (2π×(3000/60)×2.73)+(50×50×0.0026×3) 877.15
Efficiency, % (817.75/877.15)×100% 93.22
Winding losses, W (50×50×0.0026)×3 19.5 Core losses, W 26.55 Losses in PMs, W 6.97 Mechanical losses, W 16.4 Stator current, A rms 50
Stator current density, A/mm ² (50/2)/(0.4064×0.4064×3.14)×10=4.818 4.818 Mass of Cu, kg 0.2611
Mass of Fe, kg (Stator_Fe(1.6047)+Rotor_Fe(0.5392)) 2.1439 Mass of PM, kg 0.2987 Total mass (Eim components), kg 2.7037
Power density, kW/kg (0.81775/2.7037) 0.3024

14 shows Back EMF, core loss, permanent magnet loss, and rated torque of the conventional SPMSM (III).

In addition, the conventional SPMSM (III) has a maximum voltage of 8.01 [V] in counter electromotive force, an iron loss of 26.55 [W], a permanent magnet loss of 6.97 [W], a cogging torque of 50.68 [mNm], etc., and a rated torque of 2.73 [Nm].

In addition, the conventional SPMSM (III) produced similar or lower results in the material 20PN1500.

Next, as shown in FIG. 15, the proposed SPMSM (IV) is a double-pore type as follows.

In addition, the proposed SPMSM (IV) has a pair of 24 slots and 20 poles.

Here, the material of the SPMSM (IV) is 35PN380.

SPMSM (IV) Parameter Value Stator current frequency, Hz 500 Rotor speed, rpm 3,000 Shaft torque, Nm 6.55 Electromagnetic torque, Nm 7.02 Shaft power, W 2058.35
Input electric power, W (2π×(3000/60)×7.02)+(50×50×(0.0033+0.0026)×3) 2,249.65
Efficiency, % (2058.35/2,249.64)×100% 91.45
Winding losses, W (50×50×(0.0033+0.0026)×3) 44.25 Core losses, W 91.4 Losses in PMs, W 14.4 Mechanical losses, W 41.24 Stator current, A rms 50
Stator current density, A/mm ² (50/2)/(0.4064×0.4064×3.14)×10×2=9.636 9.636
Mass of Cu, kg Outer_Stator_Cu(0.4421)+Inner_Rotor_Fe(0.2611) 0.7032
Mass of Fe, kg (Outer_Stator_Fe(1.7886)+Outer_Rotor_Fe(0.3051)+
Inner_Stator_Fe(1.6047)+Inner_Rotor Fe(0.5392)) 2.0937+2.1439 = 4.2376
Mass of PM, kg Outer_Stator_PM(0.1958)+Inner_Rotor_PM(0.2987) 0.4945 Total mass (EIm components), kg 5.4353
Power density, kW/kg (2.05835/5.4353) 0.3787

As shown in FIG. 16, the SPMSM (IV) proposed by the present invention has a maximum voltage of 20 [V] and a cogging torque of 102.37 [mNm], which is 29.7% lower than that of the conventional SPMSM (I), and the iron loss is 91.4 [W], and the permanent magnet loss is 14.4 [W], etc.

In addition, the SPMSM (IV) proposed by the present invention has a rated torque of 7.02 Nm, which is 37% higher than the conventional one.

In addition, as shown in FIG. 17, the proposed SPMSM (V) is a double-pore type and is as follows.

In addition, the proposed SPMSM (V) has a pair of 24 slots and 20 poles.

Here, the material of the SPMSM (V) is 20PN1500.

SPMSM (V) Parameter Value Stator current frequency, Hz 500 Rotor speed, rpm 3,000 Shaft torque, Nm 6.57 Electromagnetic torque, Nm 6.98 Shaft power (output power), W 2066.24
Input electric power, W (2π×(3000/60)×6.98)+(50×50×(0.0033+0.0026)×3) 2237.08
Efficiency, % (2066.24/2192.83)×100% 94.23
Winding losses, W (50×50×(0.0033+0.0026)×3) 44.25 Core losses, W 67.8 Losses in PMs, W 17.78 Mechanical losses, W 41.01 Stator current, A rms 50
Stator current density, A/mm ² (50/2)/(0.4064×0.4064×3.14)×10×2=9.636 9.636
Mass of Cu, kg Outer_Stator_Cu(0.4421)+Inner_Rotor_Fe(0.2611) 0.7032
Mass of Fe, kg (Outer_Stator_Fe(1.7886)+Outer_Rotor_Fe(0.3051)+
Inner_Stator_Fe(1.6047)+Inner_Rotor Fe(0.5392)) 2.0937+2.1439 = 4.2376 Mass of PM, kg Outer_Stator_PM(0.1958)+Inner_Rotor_PM(0.2987) 0.4945 Total mass (EIm components), kg 5.4353
Power density, kW/kg (2.06624/5.4353) 0.3801

As shown in FIG. 18, the SPMSM (V) proposed by the present invention has a maximum voltage of 20.32 [V] and a cogging torque of 93.4 [mNm], which is 35.9% lower than that of the conventional SPMSM (I), and the iron loss is 67.8 [W], and the permanent magnet loss is 17.78 [W], etc.

In addition, the SPMSM (V) proposed by the present invention has a rated torque of 6.98Nm, which is 36.67% higher than the conventional one.

3. Conclusion

In the case of the conventional SPMSM, core loss (iron loss), permanent magnet loss, mechanical loss, etc. are low, but power density, torque, etc. are also low.

On the other hand, in the case of the proposed motor (electric motor), when 35PN380, which is the same material as the conventional SPMSM, is used, core loss (iron loss) is large and permanent magnet loss is increased due to the double stator structure, but high power density is obtained, and it is different from the conventional one. get similar efficiencies.

In addition, as a result of applying 20PN1500 to reduce core loss (iron loss), iron loss was reduced, but permanent magnet loss increased. However, comparing efficiency and power density, efficiency increased by 2.23% compared to conventional SPMSM, and power density increased by 2.23%. A 22.23% increase can be obtained.

19 is an exemplary cross-sectional view showing a double-gap type SPMSM according to an embodiment of the present invention, FIG. 20 is an enlarged view of part “Q” in FIG. 19, and FIG. 21 is a view according to an embodiment of the present invention. It is an exemplary longitudinal cross-sectional view showing a double-gap type SPMSM, and FIG. 22 is a view showing magnetic flux directions for explaining the double-gap type SPMSM according to an embodiment of the present invention.

In addition, FIG. 23 is a diagram showing the winding direction of illustratively the A phase among the three phases for explaining the double-gap type SPMSM according to an embodiment of the present invention, and FIGS. 24 and 25 are an embodiment of the present invention. It is a circuit diagram for explaining the double-gap type SPMSM according to , and FIG. 26 is an exemplary view showing the partition wall of the double-gap type SPMSM according to an embodiment of the present invention.

On the other hand, in order to easily understand the drawings, there is an exaggeratedly expressed part as shown in FIG. 21 .

In this way, based on the above experimental results, the present invention is proposed as follows.

As shown in FIG. 19, the double-gap surface permanent magnet synchronous motor 100 according to an embodiment of the present invention includes a first stator 110, a first rotor 120, and a first permanent magnet 130. , a second rotor 140, a second permanent magnet 150, and a second stator 160, and the like.

As shown in FIGS. 19 and 20 , the first stator 110 has a first protrusion 110p formed along the first inner circumferential surface 110s.

Here, the first protrusions 110p are 'T' shaped protrusions and are spaced apart from each other at predetermined intervals along the first inner circumferential surface 110s.

In addition, the first rotor 120 faces the first inner circumferential surface 110s to form a first outer circumferential surface 120s.

On the other hand, the first rotor 120 is manufactured by multiple stacking of silicon steel sheets or is a non-oriented electrical steel sheet produced by a company (POSCO), such as 35PN380, with a thickness of 0.35±0.05mm and a density of 7.65±0.1kg/cm ² . , core loss of 3.80W/kg or less, magnetic flux density of 1.62 or more, and space factor of 95% or more, standard dimensions and magnetic properties.

In addition, a plurality of first permanent magnets 130 are arranged along the first outer circumferential surface 120s.

In particular, in the first permanent magnet 130, N poles (blue) and S poles (red) are alternately arranged at equal intervals along the first outer circumferential surface 120s.

In addition, the second rotor 140 is integrally connected while corresponding to the inside of the first rotor 120 to form a second inner circumferential surface 140s.

On the other hand, the second rotor 140 is manufactured by multiple stacking of silicon steel sheets, or is a non-oriented electrical steel sheet produced by a company (POSCO) such as 35PN380, with a thickness of 0.35±0.05mm and a density of 7.65±0.1kg/cm ² . , core loss of 3.80W/kg or less, magnetic flux density of 1.62 or more, and space factor of 95% or more, standard dimensions and magnetic properties.

In addition, a plurality of second permanent magnets 150 are arranged along the second inner circumferential surface 140s.

In particular, in the second permanent magnet 150, the N pole (blue) and the S pole (red) are alternately arranged at equal intervals along the second inner circumferential surface 140s, but the polarity is opposite to that of the first permanent magnet 130.

In addition, the second permanent magnets 150 are formed in the same number as the first permanent magnets 130, but smaller than the number of the first protrusions 110p or the second protrusions 160p.

In addition, the number of poles proposed by the present invention becomes the number of first permanent magnets 130 or second permanent magnets 150 .

In addition, the second stator 160 has a second protrusion 160p formed along the second outer circumferential surface 160s formed to face the second inner circumferential surface 140s.

Here, the second protrusions 160p are 'T' shaped protrusions and are spaced apart at predetermined intervals along the second outer circumferential surface 160s.

In addition, the same number of second protrusions 160p as the number of first protrusions 110p is formed.

On the other hand, the present invention is carried out with 24 first protrusions 110p, 24 second protrusions 160p, 20 first permanent magnets 130 and 20 second permanent magnets 150, Quantity can be changed as needed.

As shown in FIG. 20, in the first air gap t01, an air gap is formed between the first stator 110 and the first rotor 120, and an air gap of 0.8±0.1 mm is formed. have

In addition, the second air gap t02 has a predetermined air gap formed between the second stator 160 and the second rotor 140, and has an air gap of 0.8±0.1 mm.

In addition, the first and second rotors 120 and 140 according to another embodiment of the present invention are electrical steel sheets laminated to a thickness of 0.20 ± 0.05 mm, a density of 7.65 ± 0.1 kg / cm2, and a core loss of 15.0 W / kg or less. , a magnetic flux density of 1.62 or more, and a space factor of 93% or more.

That is, the first and second rotors 120 and 140 are non-oriented electrical steel sheets produced by a company (POSCO), such as 20PN1500, with a thickness of 0.20±0.05mm, a density of 7.65±0.1kg/cm ² , and core loss (core loss). ) 15.0W/kg or less, magnetic flux density of 1.62 or more, space factor of 93% or more, standard dimensions, magnetic properties, etc.

As shown in FIG. 21 , the first and second rotors 120 and 140 rotate while being fixed to a circular plate member 170 having a rotational shaft 170r formed on one side thereof.

That is, according to the present invention, the force for rotating the first and second rotors 120 and 140 by the current applied from the windings 110w and 160w of the first and second stators 110 and 160 is the circular plate member 170 ) to rotate.

In particular, as shown in FIG. 22, since the partition wall portion 180 according to the embodiment of the present invention is formed at the boundary between the first and second rotors 120 and 140, the first and second permanent magnets It blocks mutual magnetic flux generated from (130, 150) to prevent mutual collision while improving performance such as power density.

At this time, the partition wall portion 180 is formed of a non-magnetic material such as stainless to prevent the magnetic flux of the first permanent magnet 130 from invading the second rotor 140, and The magnetic flux of the permanent magnet 150 is prevented from invading the first rotor 120 .

As shown in FIGS. 21 and 23 to 25, the present invention further includes first and second control devices 210 and 220.

In addition, the first control device 210 is connected to the first winding 110w, and the second control device 220 is connected to the second winding 160w.

Here, FIG. 23 schematically shows winding speed in case of phase A among the three phases, and circuit diagrams accordingly are shown in FIGS. 24 and 25. )

Conventionally, since the entire flow of current is controlled by one control device, there is a problem in that the entire motor cannot be operated if a part of the motor connected in multiple complexes is damaged or damaged.

Therefore, the present invention includes two control devices, the first control device 210 controls the first winding 110w wound around the first protrusion 110p, and the second control device 220 controls the first winding 110w. Since the second winding 160w wound around the second protrusion 160p is controlled, even if one of the first and second control devices 210 and 220 fails, the first and second control devices 210 and 220 are integrally formed with the other one. Rotation of the two rotors 120 and 140 can be controlled.

As shown in FIG. 26, in the present invention, the sleeve part 190 is further included, so that the first permanent magnet 130 on the outside is easily dislodged by centrifugal force or is damaged by being bumped during rotation. Alternatively, the conventional problem of the rotation direction of the second permanent magnet 150 in the inner part being out of rotation due to the centripetal force or being damaged by colliding with the surroundings has been solved.

That is, the sleeve part 190 proposed by the present invention includes a first sleeve part 190a and a second sleeve part 190b.

In addition, the first sleeve portion 190a has a hollow cylindrical shape with front and rear openings, and has a predetermined thickness to protect the first permanent magnet 130 while preventing it from coming off by wrapping around the outside of the first permanent magnet 130. It is a metal material having a predetermined tensile force and can firmly cover the first permanent magnet 130.

In addition, the second sleeve part 190b has a hollow cylindrical shape with front and rear openings, and protects the second permanent magnet 150 while preventing it from falling out by wrapping and supporting the inner circumference of the second permanent magnet 150. A metal material having a predetermined thickness and having a predetermined tensile force can firmly cover and support the second permanent magnet 150 .

In summary, the dual air gap type surface permanent magnet synchronous motor 100 according to an embodiment of the present invention includes a first stator 110 in which a first protrusion 110p is formed along a first inner circumferential surface 110s; a first rotor 120 having a first outer circumferential surface 120s facing the first inner circumferential surface 110s; a first permanent magnet 130 arranged along the first outer circumferential surface 120s; a second rotor 140 integrally connected to the first rotor 120 and having a second inner circumferential surface 140s; a second permanent magnet 150 arranged along the second inner circumferential surface 140s; and a second stator 160 having a second protrusion 160p along the second outer circumferential surface 160s formed to face the second inner circumferential surface 140s.

In addition, a first air gap t01 of a predetermined space is formed between the first stator 110 and the first rotor 120, and between the second stator 160 and the second rotor 140. A second air gap t02 of a predetermined space is formed.

In addition, the first permanent magnet 130 has N poles and S poles alternately arranged at equal intervals along the first outer circumferential surface 120s, and the second permanent magnet 150 has the second inner circumferential surface 140s. N poles and S poles are alternately arranged at regular intervals according to the polarity opposite to that of the first permanent magnet 130 .

In addition, the same number of first protrusions 110p as the second protrusions 160p is formed, and the same number of first permanent magnets 130 as the second permanent magnets 150 is formed. It is smaller than the number of protrusions 110p.

In addition, the first protrusion 110p is a 'T'-shaped protrusion and is spaced apart from the predetermined interval along the first inner circumferential surface 110s, and the second protrusion 160p is a 'T'-shaped protrusion. It is spaced apart at a predetermined interval along the second outer circumferential surface (160s).

In addition, the number of first protrusions 110p is 24, and the number of first permanent magnets 130 is 20.

In addition, the first and second rotors 120 and 140 are electrical steel sheets laminated to a thickness of 0.20 ± 0.05 mm, a density of 7.65 ± 0.1 kg / cm2, a core loss of 15.0 W / kg or less, a magnetic flux density of 1.62 or more, and a drop It is a material with a rate of 93% or more.

In addition, the first and second rotors 120 and 140 are fixed to and rotated on a circular plate member 170 having a rotation shaft 170r formed on one side thereof.

In addition, a barrier rib portion 180 formed at the boundary between the first and second rotors 120 and 140 is further included.

In addition, the barrier rib portion 180 blocks mutual magnetic flux generated from the first and second permanent magnets 130 and 150 .

In addition, the barrier rib portion 180 is formed of a non-magnetic material.

In addition, a first control device 210 for electrically controlling the first winding 110w wound around the first protrusion 110p; and a second control device 220 electrically controlling the second winding 160w wound around the second protrusion 160p. When is out of order, the other one controls rotation of the first and second rotors 120 and 140 integrally formed.

In addition, a first sleeve portion 190a having a predetermined thickness that surrounds the outside of the first permanent magnet 130 in a hollow cylindrical shape open at the front and rear to prevent and protect it from falling off, and a hollow cylinder open at the front and rear. It further includes a second sleeve part 190b having a predetermined thickness to surround and support the inside of the second permanent magnet 150 in a shape to prevent and protect it from falling out.

Also, the first and second sleeve parts 190a and 190b are made of metal.

Therefore, the dual air gap type surface permanent magnet synchronous motor 100 according to an embodiment of the present invention can expect the following effects.

According to the present invention, since it has a double-gap structure, it has an advantage of having high power density and torque.

In addition, there is an advantage in that cogging torque can be lowered than before due to the double-gap structure.

In addition, there is an advantage of increasing efficiency by improving the material of the double-gap structure under the same conditions.

In addition, since the partition wall portion 180 blocks mutual magnetic flux generated from the first and second permanent magnets, there is an advantage in that high torque can be generated.

In addition, there is an advantage that the other one can control even if one of the two is broken by having a dual control device.

In addition, there is an advantage in preventing the first and second permanent magnets 130 and 150 from falling out through the cylindrical sleeve part 190 .

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art can make various modifications, changes, and substitutions without departing from the essential characteristics of the present invention. will be.

Therefore, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings. .

The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: motor proposed by the present invention
110: first stator
120: first rotor
130: first permanent magnet
140: second rotor
150: second permanent magnet
160: second stator
170: circular plate member
180: partition wall
190: sleeve part
210: first control device
220: second control device

Claims (3)

a first stator in which a T-shaped first protrusion is formed along a first inner circumferential surface;
a first rotor having a first outer circumferential surface facing the first inner circumferential surface;
a first permanent magnet arranged along the first outer circumferential surface;
a second rotor integrally connected to the first rotor while corresponding inwardly to have a second inner circumferential surface thereof;
a second permanent magnet arranged along the second inner circumferential surface;
a second stator having a T-shaped second protrusion formed along a second outer circumferential surface formed to face the second inner circumferential surface;
a barrier rib portion formed at a boundary between the first rotor and the second rotor;
a first sleeve part made of metal that surrounds the outer periphery of the first permanent magnet in a hollow cylindrical shape with front and rear openings and prevents and protects the first permanent magnet from coming off;
a second sleeve part made of a metal material having a hollow cylindrical shape with front and rear openings, which surrounds and supports the inside of the second permanent magnet to prevent and protect the second permanent magnet from falling out;
a first control device controlling a first winding wound around the first protrusion; and
A second control device for controlling the second winding wound around the second protrusion; includes,
A first air gap having a gap of 0.8 ± 0.1 mm is formed between the first stator and the first rotor,
A second air gap having an air gap of 0.8 ± 0.1 mm is formed between the second stator and the second rotor,
In the first permanent magnet, N poles and S poles are alternately arranged at equal intervals along the first outer circumferential surface,
In the second permanent magnet, N poles and S poles are alternately arranged at equal intervals along the second inner circumferential surface, but are arranged in opposite polarities to those of the first permanent magnet;
The first protrusion is 24, which is the same number as the second protrusion,
The number of the first permanent magnets is equal to that of the second permanent magnets, but is 20 smaller than the number of the first protrusions.
When one of the first and second control devices fails, the other controls rotation of the first and second rotors integrally formed,
The barrier rib portion made of a non-magnetic material blocks mutual magnetic flux generated from the first and second permanent magnets,
The first and second rotors 120 and 140 are electrical steel sheets each having a thickness of 0.20±0.05 mm, density of 7.65±0.1 kg/cm2, core loss of 15.0 W/kg or less, magnetic flux density of 1.62 or more, and space factor. A double air gap surface permanent magnet synchronous motor, characterized in that more than 93%.
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