KR-20260066340-A - MOTOR AND METHOD OF CONTROLLING CURRENT OF MOTOR

KR20260066340AKR 20260066340 AKR20260066340 AKR 20260066340AKR-20260066340-A

Abstract

The present invention relates to a motor, and more specifically, to a technique for magnetizing or demagnetizing a magnet in a motor. According to an embodiment of the present invention, the motor comprises a stator including an armature winding to which an armature current can be applied; and a rotor rotatable with respect to the stator, comprising a field winding to which a field current can be applied; and a rotor including a first magnetized magnet, wherein the field winding may be positioned in the rotor such that the direction of the magnetizing force generated by the field winding coincides with the magnetization direction of the first magnet.

Inventors

허태관
이정석
송준영
임명섭
김기오
황윤재
이지훈
원윤재

Assignees

현대자동차주식회사
기아 주식회사
한양대학교 산학협력단

Dates

Publication Date: 20260512
Application Date: 20241104

Claims (15)

A stator comprising an armature winding to which an armature current can be applied; and As a rotor rotatable with respect to the above stator, A field winding capable of applying field current; and It includes a rotor comprising a first magnetized magnet, and A motor in which the field winding is positioned on the rotor such that the direction of the magnetizing force produced by the field winding matches the magnetization direction of the first magnet.
In claim 1, The above first magnet is a motor that is placed in the shoe of the rotor.
A motor according to claim 1, wherein the material of the first magnet is composed of a material having a lower coercivity than a neodymium magnet.
A motor according to claim 1, wherein the material of the first magnet comprises at least one selected from the group consisting of Alnico, SmCo, SmFeN, or FeN.
In claim 1, the rotor further comprises a second magnet, and The motor in which the second magnet mentioned above is a neodymium magnet.
A motor according to claim 5, wherein the second magnet is disposed on each side of the first magnet.
A current control method for a motor comprising the step of simultaneously applying current to the field winding of a rotor and the armature winding of a stator to magnetize a magnet placed in the rotor or to demagnetize the magnet.
In claim 7, the step of magnetizing or demagnetizing is, A step of inputting direct current to the field winding; and A method comprising the step of simultaneously inputting a preset armature current to the armature winding.
In claim 8, A method further comprising the step of applying a pulse current to the field winding and armature winding.
In claim 7, the step of magnetizing is, A method comprising the step of applying a magnetizing force by the armature winding to match the magnetization direction of the magnet.
In claim 10, the step of magnetizing is, A method further comprising the step of aligning the magnetization direction of the magnet with the magnetomotive force direction of the field winding.
In claim 10, A method in which the above armature current is the maximum current of the inverter for the motor.
In claim 7, the step of magnetizing is, Step of assembling a magnet before magnetization to the rotor above; and A method comprising the step of assembling the rotor and the stator.
In claim 7, the step of reducing the potato is, A method comprising the step of applying a magnetizing force by the armature winding in a direction opposite to the magnetization direction of the magnet.
In claim 14, the step of potatoing is, A method further comprising the step of forming the magnetization direction of the magnet and the magnetomotive force direction by the field winding in opposite directions.

Description

Motor and Method of Controlling Current of Motor The present invention relates to a motor, and more specifically, to a technique for magnetizing or demagnetizing a magnet in a motor. A motor consists of a stator and a rotor. Motors are applied in various fields because they can generate power through the rotation of the rotor relative to the stator, resulting from the electromagnetic interaction between the stator and the rotor. Among these, permanent magnet synchronous motors are widely used as drive motors for electric vehicles due to advantages such as excellent efficiency and the ability to be miniaturized. For permanent magnets used in permanent magnet synchronous motors, materials with high coercivity, such as neodymium, may be used. In addition, magnets with low coercivity may be used through magnetization. Magnetization can be achieved by mounting magnets with low coercivity on the rotor, assembling the stator and rotor, and then flowing a large current through the armature windings placed on the stator. However, when magnetizing low-coercivity magnets through the armature, an excessive armature current is applied, requiring the inverter capacity to be excessively large. Furthermore, it is difficult to fully magnetize or demagnetize permanent magnets with the maximum current specified by existing inverters. Additionally, if the rotor lacks a field winding, it is susceptible to unintended demagnetization. FIG. 1 illustrates a part of a cross-sectional view of a motor according to an embodiment of the present invention, and Figure 2a illustrates the magnetization distribution analysis diagram of a magnet during field magnetization, and FIG. 2b illustrates an analysis of the magnetization distribution of a magnet during field and armature magnetization according to an embodiment of the present invention, and Figure 3 shows a graph comparing the average torque for the electrical angle in the cases of Figures 2a and 2b. The specific structural or functional descriptions presented in the embodiments of the invention are merely illustrative for the purpose of explaining embodiments according to the concept of the invention, and embodiments according to the concept of the invention may be implemented in various forms. Furthermore, it should not be interpreted as being limited to the embodiments described herein, but should be understood to include all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. Meanwhile, in the present invention, terms such as "first" and/or "second" may be used to describe various components, but said components are not limited to said terms. For the sole purpose of distinguishing one component from other components, for example, without departing from the scope of rights according to the concept of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. Conversely, when it is stated that one component is "directly connected" or "directly in contact" with another component, it should be understood that there are no other components in between. Other expressions used to describe the relationship between components, such as "between" and "exactly between," or "adjacent to" and "directly adjacent to," should be interpreted in the same way. Throughout the specification, identical reference numbers denote identical components. Meanwhile, the terms used in this specification are for describing embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used in this specification, "comprises" and/or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and/or elements to the mentioned components, steps, actions, and/or elements. The present invention will be described in detail below with reference to the attached drawings. FIG. 1 shows a cross-sectional view of a motor (1) according to an embodiment of the present invention. The motor (1) is approximately cylindrical, FIG. 1 shows a part of the cross-sectional view of the motor (1), and the illustrated shape may be repeated along the circumferential direction. The motor (1) includes a stator (20) and a rotor (40). The rotor (40) is positioned radially inward with respect to the stator (20) and can rotate with respect to the stator (20). Specifically, the rotor (40) can rotate with respect to the stator (20) by means of electromagnetic interaction between the stator (20) and the rotor (40). The stator (20) includes a stator core (22) and an armature winding (24). The armature winding (24) may be wound on