Drive system with energy store and method for operating a drive system

Patent metadata

Field	Value
Publication number	US-9577564-B2
Application number	US-201314376691-A
Country	US
Kind code	B2
Filing date	Jan 28, 2013
Priority date	Feb 6, 2012
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A drive system with energy store and method for operating a drive system, an inverter powering an electric motor, the inverter being supplied from a unipolar DC-link voltage, an energy store being connected in parallel to the inverter, in particular, a film capacitor being connected in parallel to the inverter, the DC-link voltage being generated by a DC/DC converter which is supplied from an AC/DC converter, especially a rectifier, in particular, an electric current being able to be supplied to the DC link by the DC/DC converter.

First claim

What is claimed is:

1. A drive system, comprising:
an energy store;
an inverter powering an electric motor, wherein:
the inverter is supplied from a unipolar DC-link voltage,
the energy store is connected in parallel to the inverter, and
the DC-link voltage is generated by a DC/DC converter that is supplied from an AC/DC converter; and

an arrangement for detecting the DC-link voltage and connected to an arrangement of comparison, the arrangement of comparison being connected to the DC/DC converter.

2. The drive system as recited in claim 1 , wherein the energy store includes a film capacitor connected in parallel to the inverter.

3. The drive system as recited in claim 1 , wherein the AC/DC converter includes a rectifier.

4. The drive system as recited in claim 3 , wherein the rectifier is fed from a single-phase, three-phase or multiphase AC source or from a secondary winding that is coupled inductively to a primary conductor.

5. The drive system as recited in claim 1 , wherein an electric current is able to be supplied to a DC link providing the DC-link voltage by the DC/DC converter.

6. The drive system as recited in claim 4 , wherein the primary conductor is acted upon by an alternating current.

7. The drive system as recited in claim 1 , wherein the energy store includes at least one of at least one double-layer capacitor and at least one accumulator.

8. The drive system as recited in claim 1 , wherein the arrangement of comparison is connected to the DC/DC converter so that the DC/DC converter controls such a current in the DC link that a power fed into the DC link is regulated to a setpoint value.

9. The drive system as recited in claim 8 , wherein the setpoint value corresponds to one of a power setpoint value and a voltage setpoint value.

10. The drive system as recited in claim 8 , wherein the setpoint value is predefined by a primary control.

11. The drive system as recited in claim 10 , wherein the primary control determines the setpoint value predictively from a planned control sequence.

12. The drive system as recited in claim 1 , wherein the arrangement of comparison compares the detected DC-link voltage to at least one critical value.

13. A drive system, comprising:
an energy store;
an inverter powering an electric motor, wherein:
the inverter is supplied from a unipolar DC-link voltage,
the energy store is connected in parallel to the inverter, and

the DC-link voltage is generated by a DC/DC converter that is supplied from an AC/DC converter; and
a series circuit that includes a switch and a resistor, wherein the series circuit is connected in parallel to at least one of the DC link and the inverter.

14. A drive system, comprising:
an energy store;
an inverter powering an electric motor, wherein:
the inverter is supplied from a unipolar DC-link voltage,
the energy store is connected in parallel to the inverter, and
the DC-link voltage is generated by a DC/DC converter that is supplied from an AC/DC converter; and
a power able to be fed by the DC/DC converter into the DC link is limited to a limiting value, wherein at least one of:
the limiting value is greater than a power of the drive system, and
the limiting value is less than a peak power of the drive system.

15. The drive system as recited in claim 14 , wherein the power of the drive system is averaged over time.

16. The drive system as recited in claim 14 , wherein the power is a function of an operating state of the drive system.

17. A method for operating a drive system that includes an energy store, and an inverter powering an electric motor, the inverter being supplied from a unipolar DC-link voltage, the energy store being connected in parallel to the inverter, and the DC-link voltage being generated by a DC/DC converter that is supplied from an AC/DC converter, the method comprising:
feeding the inverter from a DC link that is able to be fed by the DC/DC converter, the DC/DC converter being able to be supplied from the AC/DC converter;
connecting the inverter to a control;
connecting the control, one of directly and indirectly, to the DC/DC converter and the inverter for transmitting signals so that the DC/DC converter supplies an electric power predefined by the control, to the DC link;
detecting the DC-link voltage; and
if a drop in the DC-link voltage is below a first value, feeding the electric power by the DC/DC converter into the DC link.

18. The method as recited in claim 17 , wherein the AC/DC converter includes a rectifier.

19. The method as recited in claim 17 , wherein if the DC-link voltage exceeds a second value, an energy from the DC link is supplied one of (1) to a resistor for conversion into ohmic heat, and (2) to a regenerative feedback unit for a recovery of energy into an AC system.

20. The method as recited in claim 19 , wherein the second value is greater than the first value.

21. The method as recited in claim 20 , further comprising:
taking into account a hysteresis in the comparison of the detected DC-link voltage to at least one of the first value and the second value.

22. The method as recited in claim 17 , wherein the control specifies to the DC/DC converter a value for a maximum permissible power at least one of able to be fed and fed by the DC/DC converter into the DC link, as a function of a state of the drive system.

23. A method for operating a drive system that includes an energy store, and an inverter powering an electric motor, the inverter being supplied from a unipolar DC-link voltage, the energy store being connected in parallel to the inverter, and the DC-link voltage being generated by a DC/DC converter that is supplied from an AC/DC converter, the method comprising:
feeding the inverter from a DC link that is able to be fed by the DC/DC converter, the DC/DC converter being able to be supplied from the AC/DC converter;
connecting the inverter to a control;
connecting the control, one of directly and indirectly, to the DC/DC converter and the inverter for transmitting signals so that the DC/DC converter supplies an electric power predefined by the control, to the DC link;
detecting the DC-link voltage, wherein if the DC-link voltage drops below a second value and exceeds a first value, no electric power is fed by the DC/DC converter into the DC link.

24. The method as recited in claim 23 , further comprising:
taking into account a hysteresis in the comparison of the detected DC-link voltage to at least one of the first value and the second value.

25. A method for operating a drive system that includes an energy store, and an inverter powering an electric motor, the inverter being supplied from a unipolar DC-link voltage, the energy store being connected in parallel to the inverter, and the DC-link voltage being generated by a DC/DC converter that is supplied from an AC/DC converter, the method comprising:
feeding the inverter from a DC link that is able to be fed by the DC/DC converter, the DC/DC converter being able to be supplied from the AC/DC converter;
connecting the inverter to a control; and
connecting the control, one of directly and indirectly, to the DC/DC converter and the inverter for transmitting signals so that the DC/DC converter supplies an electric power predefined by the control, to the DC link;
wherein at least one of:
a maximum permissible power at least one of able to be fed and fed by the DC/DC converter into the DC link is gre

Assignees

• Sew Eurodrive Gmbh & Co Kg

Inventors

• Schiffmann Sebastian
• Schmidt Josef
• Hauck Matthias
• Lampert Christian
• Tritschler Daniel
• Zöller Thomas

Classifications

• H02P27/06 Primary

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• H02M5/458 Primary

  using semiconductor devices only · CPC title

• H02H9/045

  adapted to a particular application and not provided for elsewhere · CPC title

• H02J7/345

  using capacitors as storage or buffering devices · CPC title

• H02P2201/03

  AC-DC converter stage controlled to provide a defined DC link voltage · CPC title