Method and damping device for damping a torsional vibration in a rotating drivetrain

• US 20060244425A1
• Filed: 06/02/2004
• Published: 11/02/2006
• Est. Priority Date: 06/13/2003
• Status: Active Grant

• Current Assignee: Nuovo Pignone Tecnologie SRL (Nuovo Pignone International SRL)
• Original Assignee: Max-Planck-Gesellschaft Zur Foerderung Der Wissenschaften e.V. (Max-Planck-Gesellschaft zur Frderung der Wissenschaften e)
• Inventors: Sihler, Christof
• Granted Patent: US 7,518,344 B2
• Time in Patent Office: Days
• US Class Current: 322/58
• CPC Class Codes: H02P 9/105 for increasing the stability

Abstract

A method and a damping device are proposed for damping a torsional oscillation in a rotating drive train. Arranged on the drive train is an electrical machine (13), which is connected to an electrical multipole (31). A damping torque is generated in the electrical machine (13) by an electrical damping member connected to the electrical machine (13). It is proposed that the damping torque has a predetermined damping frequency and is antiphase to the angular velocity of the torsional oscillation.

Claims

1. A method for damping a torsional oscillation in a rotating drive train having at least one electrical machine, comprising the step of

applying a damping torque with the electrical machine to the drive train, wherein the damping torque is applied at a predetermined damping frequency and antiphase to an angular velocity of the torsional oscillation.

2. The method according to claim 1, wherein the predetermined damping frequency essentially corresponds to a resonant frequency of the drive train.

3. The method according to claim 1, wherein the torsional oscillation of the drive train without the damping torque applied has a quality factor of more than 500.

4. The method according to claim 1, wherein the quality factor with the damping torque applied lies below 200.

5. The method according to claim 1, further comprising the steps of:

determining at least one control variable, which represents a torsional loading at at least one site in the drive train, and

controlling of the damping torque depending on the control variable in a control circuit.

6. The method according to claim 5, wherein the control variable is determined from a measurement signal from one or more sensors.

7. The method according to claim 6, wherein the sensors are at least one of azimuthally and axially spaced from one another in relation to the drive train.

8. The method according to claim 6, wherein at least one of the sensors is a magnetostrictive sensor, a strain gauge or a sensor for angular velocity measurement.

9. The method according to claim 5, wherein a feedback variable is derived from the control variable, in that the control variable is filtered, phase-shifted and inverted, the overall phase shift in the control circuit substantially amounting to 90°

, the feedback variable representing the angular velocity produced by the torsional oscillation at the resonant frequency.

10. The method according to claim 1, wherein for applying the damping torque, energy is temporarily stored in a direct current circuit with a direct current component and an alternating current component, the temporarily stored energy being taken from an alternating current circuit to which the electrical machine is connected.

11. The method according to claim 10, wherein the energy is temporarily stored with at least one coil in the direct current circuit.

12. The method according to claim 10 wherein the energy is temporarily stored with at least one capacitor in the direct current circuit.

13. The method according to claim 10, further comprising the following steps:

providing a target value for current control or voltage control of the direct current circuit from the direct current component and the alternating current component, the alternating current component representing the feedback variable and having a frequency which substantially corresponds to the resonant frequency, and

controlling the direct current circuit with the target value via a current converter connected to the alternating current circuit, effective power being brought about in the electrical machine via the alternating current circuit.

14. The method according to claim 13, wherein the damping power is adjusted via the size of the direct current component, the size of the alternating current component or both.

15. The method according to claim 13, wherein a maximum of 5% of the power converted by the electrical machine is used via the current converter for damping the torsional oscillation.

16. The method according to claim 1, wherein the overall mass of the rotating components of the drive train is more than 20 tons.

17. The method according to claim 1, wherein the torsional oscillation of at least one further drive train which has at least one further electrical machine is damped, wherein the drive trains having different resonant frequencies.

18. The method according to claim 1, wherein the electrical machine is a synchronous machine.

19. The method according to claim 10, wherein current flows in the direct current circuit only on occurrence of the torsional oscillation in the drive train.

20. The method according to claim 1, wherein a plurality of torsional oscillations with different frequencies of the rotating drive train are damped, the damping torque containing damping frequency components with predetermined damping frequencies and the damping frequency components being each antiphase to the angular velocity of the corresponding torsional oscillation.

21. The method according to claim 20, wherein the predetermined damping frequencies substantially correspond to resonant frequencies of the drive train.

22. The method according to claim 20, further comprising the following steps:

determining a plurality of control variables

providing a plurality of feedback variables from the control variables for the torsional oscillations, each feed back variable having a frequency that is substantially equal to the frequency of the corresponding torsional oscillations, providing the target value for current control or voltage control of the direct current circuit from the direct current component and the alternating current component, the alternating current component representing the sum of the feed back variables, and

controlling the direct current circuit with the target value via the current converter connected to the alternating current circuit, effective power being brought about in the electrical machine via the alternating current circuit.

23. A damping device for damping a torsional oscillation in a rotating drive train having an electrical machine and an electrical multipole connected to the electrical machine

the damping device being connected via the electrical multipole to the electrical machine and being arranged for generating a damping torque in the electrical machine wherein the damping torque has a predetermined damping frequency and is antiphase to the angular velocity of the torsional oscillation.

24. The damping device according to claim 23, wherein the predetermined damping frequency substantially corresponds to a resonant frequency of the drive train.

25. The damping device according to claim 23 wherein the torsional oscillation of the drive train without the damping torque applied has a quality factor of more than 500.

26. The damping device according to claim 25, wherein the quality factor with the damping torque applied lies below 200.

27. The damping device according to claim 23, further comprising a controller, which controls the strength of the damping torque depending on a control variable.

28. The damping device according to claim 27, further comprising measuring equipment and at least one sensor for determining the control variable, the measuring equipment being linked on the input side to the sensor.

29. The damping device according to claim 28, wherein a plurality of sensors are provided, which are azimuthally or axially spaced from one another in relation to the drive train.

30. The damping device according to claim 28, wherein the at least one sensor is a magnetostrictive sensor or a strain gauge or an angular velocity sensor.

31. The damping device according to claim 28, wherein the measuring equipment has at least one of a filter, which is tuned to the resonant frequency, a phase-shifter and an inverter for creating a feedback variable, the feedback variable being an oscillating signal at the damping frequency.

32. The damping device according to claim 23, further comprising an energy storage for intermediate storage of energy, the energy being drawn from the electrical machine or the multipole.

33. The damping device according to claim 32, wherein the energy storage has at least one coil, which is arranged in a direct current circuit with an alternating current component.

34. The damping device according to claim 32 further comprising a current converter, via which the energy storage is connectable to the multipole under current control or voltage control.

35. The damping device according to claim 34, wherein the energy storage has at least one capacitor, which is arranged on the direct current side of the current converter.

36. The damping device according to claim 32, wherein the controller has an adder with two inputs, whose one input is connected to the measuring equipment which outputs the feedback variable and to whose other input a direct current component to be added is applied, the output issuing a target value for a control system of the current converter.

37. The damping device according to claim 36, wherein the damping power is controllable in that in the controller the amplification factor of the feedback variable and the size of the direct current component are controllable.

38. The damping device according to claim 35, wherein the current converter controls a maximum power level of 5% of the power converted by the electrical machine.

39. The damping device according to claim 23, wherein the drive train has an overall mass of over 20 tons.

40. The damping device according to claim 23, wherein one control module and a plurality of power modules are provided, where the power modules can be controlled in parallel by the control module in order to achieve a larger damping power.

41. The damping device according to claim 23, wherein the electrical machine is a synchronous machine.

42. The damping device according to claim 33, wherein the direct current circuit is current-free when no torsional oscillation occurs.

43. The damping device according to claim 28, further comprising a plurality of measuring equipments with which feedback variables may be determined for various torsional oscillations of the drive train at different frequencies and which are connected to the one or the plurality of sensors.

44. The damping device according to claim 43, wherein the plurality of sensors are arranged at sites on the drive train at which the deformations caused by the torsional oscillations are maximal.

45. The damping device according to claim 43, further comprising a feedback variable adder, which adds the feedback variables output by measuring equipment and whose output is linked to the input of the adder of the controller.

47. A method of using a damping device according to claim 23 for damping a torsional oscillation in a drive train of a turbine or wind power generator, a ship drive system, a helicopter drive system or a lift drive system or in an upright shaft.

46. (canceled)