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DE-102024133129-A1 - Rotor arrangement, electric machine and method

DE102024133129A1DE 102024133129 A1DE102024133129 A1DE 102024133129A1DE-102024133129-A1

Abstract

A rotor arrangement (50) comprises a rotor core (52), first permanent magnets (71) and second permanent magnets (72), wherein the first permanent magnets (71) have a first magnetic material with a first magnetic coercive field strength and the second permanent magnets (72) have a second magnetic material with a second magnetic coercive field strength, wherein the first magnetic coercive field strength is higher than the second magnetic coercive field strength, wherein the rotor arrangement (50) alternately comprises two adjacent first pole regions (68, 61; 64, 65) with the first permanent magnets (71) and two adjacent second pole regions (62, 63; 66, 67) with the second permanent magnets (72), wherein the two adjacent first pole regions (68, 61; 64, 65) are magnetized oppositely to each other in order to achieve the desired magnetic field strength by remagnetizing the second pole regions (62, 63, 66, 67). 67) to enable a first number of poles of the rotor arrangement (50) opposite to the respective adjacent first pole region (68, 61, 64, 65) and to enable a second number of poles of the rotor arrangement (50) by remagnetizing the second pole regions (62, 63, 66, 67) in accordance with the respective adjacent first pole region (68, 61, 64, 65), wherein the first number of poles is twice as large as the second number of poles.

Inventors

  • Raphael Oestreicher
  • Thomas Hubert

Assignees

  • DR. ING. H.C. F. PORSCHE AKTIENGESELLSCHAFT

Dates

Publication Date
20260513
Application Date
20241113

Claims (9)

  1. Rotor arrangement (50) comprising a rotor core (52), first permanent magnets (71) and second permanent magnets (72), wherein the first permanent magnets (71) comprise a first magnetic material with a first magnetic coercive field strength and the second permanent magnets (72) comprise a second magnetic material with a second magnetic coercive field strength, wherein the first magnetic coercive field strength is higher than the second magnetic coercive field strength, wherein the rotor arrangement (50) alternately comprises two adjacent first pole regions (68, 61; 64, 65) with the first permanent magnets (71) and two adjacent second pole regions (62, 63; 66, 67) with the second permanent magnets (72), wherein the two adjacent first pole regions (68, 61; 64, 65) are magnetized oppositely to each other in order to achieve remagnetization of the second pole regions (62, 63, 66, 67) to enable a first number of poles of the rotor arrangement (50) opposite to the respective adjacent first pole area (68, 61, 64, 65) and to enable a second number of poles of the rotor arrangement (50) by remagnetizing the second pole areas (62, 63, 66, 67) in accordance with the respective adjacent first pole area (68, 61, 64, 65), wherein the first number of poles is twice as large as the second number of poles.
  2. Rotor arrangement (50) according to Claim 1 , in which the first magnetic material is neodymium-iron-boron.
  3. Rotor arrangement (50) according to Claim 1 or 2 , in which the first magnetic material has a magnetic coercive field strength which is greater than at least one first limiting coercive field strength from a first group consisting of: - 400,000 A/m, - 500,000 A/m, - 600,000 A/m, and - 700,000 A/m.
  4. Rotor arrangement (50) according to one of the preceding claims, wherein the second magnetic material comprises at least one magnetic material from a group of magnetic materials consisting of: - aluminum nickel cobalt, and - iron nitride.
  5. Rotor arrangement (50) according to one of the preceding claims, wherein the second magnet material has a magnetic coercive field strength which is less than at least a second limiting coercive field strength from a second group consisting of: - 300,000 A/m, - 250,000 A/m, - 200,000 A/m, and - 150,000 A/m.
  6. An electric machine (20) comprising a rotor arrangement (50) according to one of the preceding claims, a stator arrangement (30), and a current supply arrangement (23), whereby the stator arrangement (30) comprises a winding arrangement (39), and whereby the current supply arrangement (23) is configured to: - in an operating mode, energize the winding arrangement (39) to generate torque in the rotor arrangement (50), and - in a configuration mode, perform a remagnetization of the second pole regions (62, 63, 66, 67) by energizing the winding arrangement (39).
  7. Method for operating an electric machine (20), wherein the electric machine (20) comprises a rotor arrangement (50), a stator arrangement (30) and a current supply arrangement (23), wherein the stator arrangement (30) comprises a winding arrangement (39), wherein the rotor arrangement (50) comprises a rotor core (52), first permanent magnets (71) and second permanent magnets (72), wherein the first permanent magnets (71) comprise a first magnetic material with a first coercive field strength and the second permanent magnets (72) comprise a second magnetic material with a second coercive field strength, wherein the first coercive field strength is higher than the second coercive field strength, wherein the rotor arrangement (50) alternately comprises two adjacent first pole regions (68, 61; 64, 65) with the first permanent magnets (71) and two adjacent second pole regions (62, 63; 66, 67) with the second permanent magnets (72) wherein the two adjacent first pole regions (68, 61; 64, 65) are magnetized oppositely to each other, the method comprising the following steps: A) under a predetermined first condition, the second pole regions (62, 63, 66, 67) are remagnetized by energizing the winding arrangement (39) by means of the energizing arrangement (23) into a first configuration state in which the second pole regions (62, 63, 66, 67) are magnetized oppositely to the respective adjacent first pole region (68, 61; 64, 65) in order to effect a first number of poles of the rotor arrangement (50), and B) under a predetermined second condition, the second pole regions (62, 63, 66, 67) are remagnetized by energizing the winding arrangement (39) by means of the energizing arrangement (23) into a second configuration state in which the second pole regions (62, 63, 66, 67) are magnetized according to the respective adjacent first pole region (68, 61, 64, 65) in order to form a second number of poles of the rotor arrangement (50) effect, where the first pole number is twice as large as the second pole number.
  8. Procedure according to Claim 7 , which includes the following step: C) the winding arrangement (39) is energized by the current-energizing arrangement (23) to generate a torque in the rotor arrangement (50), the energizing being carried out depending on whether the second pole regions (62, 63, 66, 67) are in the first configuration state or in the second configuration state.
  9. Procedure according to Claim 7 or 8 , which includes the following step: D) under a given third condition, the second pole regions (62, 63, 66, 67) are brought into a third configuration state by energizing the winding arrangement (39) using the energizing arrangement (23), in which the second pole regions (62, 63, 66, 67) are demagnetized.

Description

The invention relates to a rotor arrangement, an electric machine and a method for operating an electric machine. The EP 2 246 961 A1 shows a permanent magnet rotor in which a magnetic pole is formed from a first permanent magnet (71) and a second permanent magnet (72), wherein the products of the coercive force are different with the magnetization direction. The JP 5 355 055 B2 shows a rotor that has magnets with variable magnetic force and magnets with fixed magnetic force. The JP 6 371 550 B2 Figure 1 shows an electric machine in which a permanent magnet is magnetized by a magnetic field, the magnetic field being formed by an armature current. The EP 2 360 814 B1 shows a rotor with a rotor core and rotor poles, using two or more types of permanent magnets. The EP 2 136 467 B1 shows a permanent magnet rotor arrangement in which two types of permanent magnets with different shapes or different magnetic properties are used. The CN 114 498 983 B shows a motor with adjustable magnetic flux and variable magnetic circuit with three sections and series/parallel connection. It is therefore an object of the invention to provide a new rotor arrangement, a new electric machine and a new method for operating an electric machine. This problem is solved by the subject matter of claim 1 and the dependent claims. A rotor assembly comprises a rotor core, first permanent magnets, and second permanent magnets, wherein the first permanent magnets have a first magnetic material with a first magnetic coercive field strength, and the second permanent magnets have a second magnetic material with a second magnetic coercive field strength, the first magnetic coercive field strength being higher than the second magnetic coercive field strength. The rotor assembly alternately has two adjacent first pole regions with the first permanent magnets and two adjacent second pole regions with the second permanent magnets. The two adjacent first pole regions are magnetized oppositely to each other. A first number of poles of the rotor assembly can be achieved by remagnetizing the second pole regions in the opposite direction to the respective adjacent first pole region. A second number of poles of the rotor assembly can be achieved by remagnetizing the second pole regions in the same direction as the respective adjacent first pole region. The first number of poles is twice the second number of poles. The rotor assembly allows the number of rotor poles to be changed, requiring the remagnetization of only half of the pole regions. Changing the number of poles can influence machine characteristics such as the torque-speed characteristic or the efficiency. According to a preferred embodiment, the first magnet material comprises neodymium-iron-boron. This magnet material has a high coercive field strength and enables a high torque. According to a preferred embodiment, the first magnetic material has a magnetic coercive field strength which is greater than at least one first limiting coercive field strength from a first group consisting of: - 400,000 A/m, - 500,000 A/m, - 600,000 A/m, and - 700,000 A/m. Magnet reversal can be easily avoided at these coercive field strengths. According to a preferred embodiment, the second magnetic material comprises at least one magnetic material from a group of magnetic materials consisting of: - Aluminum-nickel-cobalt, and - Iron nitride. These magnetic materials can be easily remagnetized. According to a preferred embodiment, the second magnetic material has a magnetic coercive field strength which is smaller than at least a second limiting coercive field strength from a second group consisting of: - 300,000 A/m, - 250,000 A/m, - 200,000 A/m, and - 150,000 A/m. A remagnetization can be achieved in this way. According to a preferred embodiment, an electric machine has such a rotor arrangement, a stator arrangement and a current supply arrangement, wherein the stator arrangement has a winding arrangement, and wherein the current supply arrangement is configured to - in an operating mode to energize the winding arrangement to generate torque in the rotor arrangement and - to perform a remagnetization of the second pole areas in a configuration mode by energizing the winding arrangement. Such an electric machine has many uses. A method for operating an electric machine, wherein the electric machine comprises a rotor arrangement, a stator arrangement, and a current supply arrangement, wherein the stator arrangement comprises a winding arrangement, wherein the rotor arrangement comprises a rotor core, first permanent magnets, and second permanent magnets, wherein the first permanent magnets comprise a first magnetic material with a first coercive field strength, and the second permanent magnets comprise a second magnetic material with a second coercive field strength, wherein the first coercive field strength is higher than the second coercive field strength, and wherein the rotor arrangement alternately comprises tw