Method of operating an electromechanical converter, a controller and a computer program product

• US 8,710,785 B2
• Filed: 12/18/2008
• Issued: 04/29/2014
• Est. Priority Date: 12/18/2007
• Status: Active Grant

• Current Assignee: Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno
• Original Assignee: Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno
• Inventors: Foster, Darren Leigh
• Primary Examiner(s): Santana, Eduardo Colon
• Assistant Examiner(s): DINH, THAI T
• Application Number:
  US12/808,842
• Publication Number:
  US 20120025747A1
• Time in Patent Office: 1,958 Days
• Field of Search: 318/400.02, 318/400.41, 318/716, 318/721, 318/722, 318/491, 318/493, 318/495, 310/109, 310/112, 310/113, 310/114, 310/115, 310/154.01, 310/154.08, 310/154.09, 310/154.33, 310/154.34, 310/266
• US Class Current: 318/495
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/44 related to combustion engines
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2270/145 Structure borne vibrations
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: H02K 16/025 with rotors and moving stators connected in a cascade cascade arrangement of an asynchronous motor with another dynamo-electric motor or converter H02K17/34
• CPC Class Codes: H02K 51/00 Dynamo-electric gears, i.e. dynamo-electric means for transmitting mechanical power from a driving shaft to a driven shaft and comprising structurally interrelated motor and generator parts
• CPC Class Codes: H02P 21/0089 using field weakening
• CPC Class Codes: H02P 21/22 Current control, e.g. using a current control loop
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

The invention relates to a method of operating an electromechanical converter, in particular an electric variable transmission, provided with a primary shaft having a rotor mounted thereon, a secondary shaft having an interrotor mounted thereon, and a stator, fixedly mounted to the housing of the electromechanical converter, wherein, viewed from the primary shaft in radial direction, the rotor, the interrotor and the stator are arranged concentrically relative to each other. The rotor and the stator are designed with one or more windings. Further, the interrotor forms one whole both mechanically and electromagnetically, and is arranged as a conductor for magnetic flux in an at least tangential direction. The method comprises the step of variably controlling a magnetic rotor flux.

Claims

1. A method of operating an electromechanical converter, in particular an electric variable transmission, provided with a primary shaft having a rotor mounted thereon, a secondary shaft having an interrotor mounted thereon, and a stator, fixedly mounted to the housing of the electromechanical converter, wherein, viewed from the primary shaft in radial direction, the rotor, the interrotor and the stator are arranged concentrically relative to each other, and wherein the rotor and the stator are designed with one or more windings, wherein the interrotor forms one whole both mechanically and electromagnetically, and is arranged as a conductor for magnetic flux in an at least tangential direction, the method comprising the step of variably controlling a magnetic rotor flux such that a magnetic saturation in the interrotor decreases, and the step of determining the magnetic rotor flux from desired parameters associated with the interrotor, wherein the magnetic rotor flux is determined by retrieving a value from a look-up table and/or by numerically modelling the physical behaviour of the electromechanical converter.

2. The method according to claim 1, wherein the one or more windings of the rotor and/or the stator are of a mono- or polyphase type, and are electrically accessible.

3. The method according to claim 2, wherein the interrotor further comprises a magnetic and an electric circuit, the magnetic circuit including a magnetic flux conducting cylinder and the electric circuit including a number of electric circuit-forming windings extending in the flux conducting cylinder, and wherein the interrotor is arranged as a conductor for the magnetic flux in a tangential and radial direction so that exertion of a direct torque between the rotor and the stator can occur upon magnetic saturation of the interrotor.

4. The method according to claim 2, wherein the magnetic rotor flux is reduced under stator field weakening conditions.

5. The method according to claim 2, wherein electrically accessible windings of the rotor and/or the stator are connected to a control unit for controlling electrical currents flowing in the windings.

6. The method according to claim 2, wherein the magnetic rotor flux is reduced the magnetic flux is reduced by reducing the direct-axis current in the rotor, preferably by implementing a vector control scheme.

7. The method according to claim 1, wherein the interrotor further comprises a magnetic and an electric circuit, the magnetic circuit including a magnetic flux conducting cylinder and the electric circuit including a number of electric circuit-forming windings extending in the flux conducting cylinder, and wherein the interrotor is arranged as a conductor for the magnetic flux in a tangential and radial direction so that exertion of a direct torque between the rotor and the stator can occur upon magnetic saturation of the interrotor.

8. The method according to claim 7, wherein the magnetic rotor flux is reduced under stator field weakening conditions.

9. The method according to claim 7, wherein electrically accessible windings of the rotor and/or the stator are connected to a control unit for controlling electrical currents flowing in the windings.

10. The method according to claim 7, wherein the magnetic rotor flux is reduced the magnetic flux is reduced by reducing the direct-axis current in the rotor, preferably by implementing a vector control scheme.

11. The method according to claim 1, wherein the magnetic rotor flux is reduced under stator field weakening conditions.

12. The method according to claim 11, wherein electrically accessible windings of the rotor and/or the stator are connected to a control unit for controlling electrical currents flowing in the windings.

13. The method according to claim 11, wherein the magnetic rotor flux is reduced the magnetic flux is reduced by reducing the direct-axis current in the rotor, preferably by implementing a vector control scheme.

14. The method according to claim 1, wherein electrically accessible windings of the rotor and/or the stator are connected to a control unit for controlling electrical currents flowing in the windings.

15. The method according to claim 14, wherein the magnetic rotor flux is reduced the magnetic flux is reduced by reducing the direct-axis current in the rotor, preferably by implementing a vector control scheme.

16. The method according to claim 1, wherein the magnetic rotor flux is reduced the magnetic flux is reduced by reducing the direct-axis current in the rotor, preferably by implementing a vector control scheme.

17. A controller comprising a processor arranged for operating an electromechanical converter, in particular an electric variable transmission, provided with a primary shaft having a rotor mounted thereon, a secondary shaft having an interrotor mounted thereon, and a stator, fixedly mounted to the housing of the electromechanical converter, wherein, viewed from the primary shaft in radial direction, the rotor, the interrotor and the stator are arranged concentrically relative to each other, and wherein the rotor and the stator are designed with one or more windings, wherein the interrotor forms one whole both mechanically and electromagnetically, and is arranged as a conductor for magnetic flux in an at least tangential direction, wherein the processor is arranged for variably controlling a magnetic rotor flux such that a magnetic saturation in the interrotor decreases and determining the magnetic rotor flux from desired parameters associated with the interrotor, wherein the magnetic rotor flux is determined by retrieving a value from a look-up table and/or by numerically modelling the physical behaviour of the electromechanical converter.

18. A computer program embodied on a non-transitory computer readable medium comprising computer readable code for causing a processor to perform a method of operating an electromechanical converter, in particular an electric variable transmission, provided with a primary shaft having a rotor mounted thereon, a secondary shaft having an interrotor mounted thereon, and a stator, fixedly mounted to the housing of the electromechanical converter, wherein, viewed from the primary shaft in radial direction, the rotor, the interrotor and the stator are arranged concentrically relative to each other, and wherein the rotor and the stator are designed with one or more windings, wherein the interrotor forms one whole both mechanically and electromagnetically, and is arranged as a conductor for magnetic flux in an at least tangential direction, the method comprising the step of variably controlling a magnetic rotor flux such that a magnetic saturation in the interrotor decreases and the step of determining the magnetic rotor flux from desired parameters associated with the interrotor, wherein the magnetic rotor flux is determined by retrieving a value from a look-up table and/or by numerically modelling the physical behaviour of the electromechanical converter.