DRIVE CIRCUIT FOR AN AIR BEARING MOTOR

• US 20150130384A1
• Filed: 09/02/2014
• Published: 05/14/2015
• Est. Priority Date: 08/30/2013
• Status: Active Grant

• Current Assignee: Liebherr-Elektronik GmbH (Liebherr-International AG)
• Original Assignee: Liebherr-Elektronik GmbH (Liebherr-International AG)
• Inventors: Mahdavi, Nejat, Cremer, Ralf, Brodeau, Pierre
• Granted Patent: US 9,571,014 B2
• Time in Patent Office: Days
• US Class Current: 318/442
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2220/50 Structural details of electrical machines
• CPC Class Codes: B60L 2240/34 Cabin temperature
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 9/00 Electric propulsion with power supply external to the vehicle electric propulsion for monorail vehicles, suspension vehicles or rack railways B60L13/00; in combination with batteries or fuel cells within the vehicle B60L50/53
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems
• CPC Class Codes: H02P 23/00 Arrangements or methods for the control of AC motors characterised by a control method other than vector control
• CPC Class Codes: H02P 29/025 the fault being a power interruption
• CPC Class Codes: H02P 4/00 Arrangements specially adapted for regulating or controlling the speed or torque of electric motors that can be connected to two or more different electric power supplies vector control H02P21/00
• 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 10/72 Electric energy management in electromobility

Abstract

The invention relates to a drive circuit for an electric motor having an aerodynamic support of the motor shaft, wherein the drive circuit comprises at least one storage means for storing electrical energy by which the electric motor can be fed with electrical energy on a failure of the supply voltage or intermediate circuit voltage to obtain a minimum speed of the motor shaft required for the air support at least at times.

Claims

1. A drive circuit for an electric motor having an aerodynamic support of the motor shaft, wherein

the drive circuit comprises at least one means for storing electrical energy by which the electric motor is supplied with electrical energy on a failure of the supply voltage or intermediate circuit voltage to obtain a minimum speed of the motor shaft required for the air support at least at times.

2. A drive circuit in accordance with claim 1, wherein the at least one storage means can be charged by the supply voltage or intermediate circuit voltage.

3. A drive circuit in accordance with claim 2, wherein means are provided for measuring the temperature of the at least one storage means and the charging voltage of the at least one storage means can be selected in dependence on the measured temperature.

4. A drive circuit in accordance with claim 1, wherein a control is provided which recognizes a voltage failure and switches to the emergency supply of the electric motor by the at least one storage means.

5. A drive circuit in accordance with claim 1, wherein a control is provided which recognizes a falling below of a minimum voltage by the supply voltage/intermediate circuit voltage and connects the at least one storage means to keep the intermediate circuit voltage constantly over the minimum value.

6. A drive circuit in accordance with claim 1, wherein the control actuates a coupling of the electric motor at the output side on a voltage failure to switch the motor load-free.

7. A drive circuit in accordance with claim 1, wherein the at least one electrical storage means comprises a low voltage store or a high voltage store.

8. A drive circuit in accordance with claim 1, wherein the at least one electrical storage means comprises at least one double layer capacitor and/or at least one rechargeable chemical battery cell, in particular an Li ion cell.

9. A drive circuit in accordance with claim 1, wherein the at least one storage means comprises a low voltage store and is connected to the supply voltage or to the intermediate circuit via a bidirectional galvanically separated DC/DC converter.

10. A drive circuit in accordance with claim 1, wherein the at least one storage means comprises a high voltage store and is connected to the supply voltage or to the intermediate circuit via a bidirectional DC/DC converter not galvanically separated.

11. A drive circuit in accordance with claim 1, wherein the at least one storage means comprises a high voltage store and is connected to the supply voltage or to the intermediate circuit for charging the storage means via a unidirectional DC/DC converter and the store feeds the electric motor via a diode on a failure of the supply voltage/intermediate circuit voltage.

12. A drive circuit in accordance with claim 1, wherein the at least one storage means comprises a high voltage store and is connected via a resistor element, in particular a connected resistor element, to the supply voltage or to the intermediate circuit for charging the storage means and the store feeds the electric motor via a diode on a failure of the supply voltage/intermediate circuit voltage.

13. A drive circuit in accordance with claim 1, wherein the charge state of the at least one storage means can be monitored by the control and the DC/DC converter or the switchable resistor element can be controlled by the control unit in dependence on the charge state.

14. A drive circuit in accordance with claim 1, wherein the electric motor is fed via an inverter by the supply voltage/intermediate circuit voltage and the inverter can preferably be controlled or regulated by the control in dependence on the detected motor speed.

15. A drive circuit in accordance with claim 14, wherein the inverter is or can be connected to the at least one storage means, in particular via a DC/DC converter, to ensure an emergency supply of the inverter on a failure of the supply voltage/intermediate circuit voltage.

16. An air-conditioning system, in particular for a rail vehicle, comprising an air-supported electric motor for driving a compressor and a drive circuit in accordance with claim 1.

17. An air-conditioning system in accordance with claim 16, wherein the electric motor is connected to the compressor via at least one coupling means and can be decoupled from the compressor at the output side on a failure of the supply voltage/intermediate circuit voltage.

18. A drive circuit in accordance with claim 3, wherein a control is provided which recognizes a voltage failure and switches to the emergency supply of the electric motor by the at least one storage means.

19. A drive circuit in accordance with claim 2, wherein a control is provided which recognizes a voltage failure and switches to the emergency supply of the electric motor by the at least one storage means.

20. A drive circuit in accordance with claim 18, wherein a control is provided which recognizes a falling below of a minimum voltage by the supply voltage/intermediate circuit voltage and connects the at least one storage means to keep the intermediate circuit voltage constantly over the minimum value.