System and method for damping of torsional oscillations in large inertial energy storage systems

Patent metadata

Field	Value
Publication number	US-11038398-B2
Application number	US-201816019206-A
Country	US
Kind code	B2
Filing date	Jun 26, 2018
Priority date	Jun 26, 2018
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

An energy storage system includes a power source configured to generate power. The energy storage system also includes an induction machine coupled to an inertial flywheel, the induction machine configured to receive electrical energy from the power source, store the energy in the flywheel, and deliver a first portion of the energy to a first pulsed load. The energy storage system further includes a damping network configured to receive and absorb a second portion of the energy at a controlled rate to regulate torsional oscillations in a rotary motion of the flywheel caused by load swings or pulsations of the first pulsed load.

First claim

What is claimed is:

1. A rotating energy storage system comprising:
a power source configured to generate power;
an induction machine coupled to an inertial flywheel, the induction machine configured to receive electrical energy from the power source, store the energy in the flywheel, and deliver a first portion of the energy to a first pulsed load; and
a damping network configured to receive and absorb a second portion of the energy at a controlled rate to regulate torsional oscillations in a rotary motion of the flywheel caused by load swings or pulsations of the first pulsed load.

2. The rotating energy storage system of claim 1 , wherein the damping network comprises a polyphase network with a controllable range of leading VAR, lagging VAR, and multiple power dissipation elements, wherein the multiple power dissipation elements comprise:
a saturable polyphase inductor controlled by an external DC bias power supply and configured to vary inductance over a range;
a polyphase resistance bank in series with the saturable polyphase inductor; and
a capacitor bank comprising a combination of fixed and variable capacitors.

3. The rotating energy storage system of claim 1 , wherein the induction machine is a wound-rotor induction machine that comprises:
a first stator port configured to receive the energy from the power source;
a second stator port configured to output the first portion of the energy to the first pulsed load; and
a first rotor port coupled to an bidirectional AC power converter providing excitation to the induction machine.

4. The rotating energy storage system of claim 3 , wherein the induction machine further comprises:
a third stator port coupled to the damping network.

5. The rotating energy storage system of claim 3 , wherein the induction machine further comprises:
a second rotor port coupled to the damping network; and
a third stator port coupled to a second pulsed load, wherein the first pulsed load comprises a DC pulsed load and the second pulsed load comprises an AC pulsed load,
wherein the first stator port includes a shunt resistive polyphase network connected in parallel to lower an effective input impedance of the induction machine.

6. The rotating energy storage system of claim 5 , wherein the first rotor port comprises a first winding centered on a rotor direct axis, and the second rotor port comprises a second winding centered on a rotor quadrature axis,
wherein the first and second windings are independently operable for providing rotor excitation or receiving energy from windings of the stator ports.

7. The rotating energy storage system of claim 5 , wherein an overall principal resonant speed of the flywheel is altered by operation of the damping network due to changes of a characteristic electrical impedance of a winding of the first stator port or the third stator port.

8. The rotating energy storage system of claim 1 , wherein the second portion of the energy received at the damping network comprises both real and reactive power with a leading or lagging power factor.

9. The rotating energy storage system of claim 1 , further comprising:
a control system configured to detect oscillations in a rotation speed of the flywheel, determine a frequency of the oscillations, and control operation of the damping network to change a torsional damping response and improve system stability for dynamic load perturbations.

10. The rotating energy storage system of claim 9 , wherein the control system comprises:
a load controller configured to switch pulsed loads responsive to both real and reactive power output of a triply-fed induction machine; and
a torsional oscillation damping controller configured to receive input signals of shaft speed, flywheel torque, and line or load power and commands gating and a current level of the damping network, the torsional oscillation damping controller configured to modulate both real and reactive power draw or regeneration at a line input of the triply-fed induction machine to dampen or suppress oscillations in shaft speed or torque.

11. A rotating energy storage system comprising:
a power source configured to generate AC power;
a triply-fed induction machine coupled to an inertial flywheel and comprising multiple stator ports and at least one rotor port, the triply-fed induction machine configured to receive energy from the power source, store the energy in the flywheel, and deliver a first portion of the energy to a first pulsed load; and
a damping network configured to receive a second portion of the energy at a torsional damping voltage to regulate oscillations in a rotation speed of the flywheel caused by load swings or pulsations of the first pulsed load.

12. The rotating energy storage system of claim 11 , wherein the damping network comprises a polyphase network with a controllable range of leading VAR, lagging VAR, and multiple power dissipation elements, wherein the multiple power dissipation elements comprise:
a saturable polyphase inductor controlled by an external DC bias power supply and configured to vary inductance over a range;
a polyphase resistance bank in series with the saturable polyphase inductor; and
a capacitor bank comprising a combination of fixed and variable capacitors.

13. The rotating energy storage system of claim 11 , wherein the triply-fed induction machine is a wound-rotor induction machine that comprises:
a first stator port configured to receive the energy from the power source;
a second stator port configured to output the first portion of the energy to the first pulsed load; and
a first rotor port coupled to an bidirectional AC power converter providing excitation to the induction machine.

14. The rotating energy storage system of claim 13 , wherein the triply-fed induction machine further comprises:
a third stator port coupled to the damping network.

15. The rotating energy storage system of claim 13 , wherein the triply-fed induction machine further comprises:
a second rotor port coupled to the damping network; and
a third stator port coupled to a second pulsed load, wherein the first pulsed load comprises a DC pulsed load and the second pulsed load comprises an AC pulsed load,
wherein the first stator port includes a shunt resistive polyphase network connected in parallel to lower an effective input impedance of the induction machine.

16. The rotating energy storage system of claim 15 , wherein the first rotor port comprises a first winding centered on a rotor direct axis, and the second rotor port comprises a second winding centered on a rotor quadrature axis,
wherein the first and second windings are independently operable for providing rotor excitation or receiving energy from windings of the stator ports.

17. The rotating energy storage system of claim 15 , wherein an overall principal resonant speed of the flywheel is altered by operation of the damping network due to changes of a characteristic electrical impedance of a winding of the first stator port or the third stator port.

18. The rotating energy storage system of claim 11 , wherein the second portion of the energy received at the damping network comprises both real and reactive power with a leading or lagging power factor.

19. The rotating energy storage system of claim 11 , further comprising:
a control system configured to detect the oscillations in the rotation speed of the flywheel, determine a frequency of the oscillations, and control operation of the damping network to change a torsional damping response and improve system

Assignees

• Raytheon Co

Inventors

• Kuznetsov Stephen

Classifications

• F03G3/08

  using flywheels · CPC title

• F16F15/30

  Flywheels (F16F15/16, F16F15/28 take precedence; suppression of vibrations in rotating systems using elastic members or friction-damping members moving with the system, {i.e. split flywheels or single masses connected to a hub by elastic members or friction-damping members} F16F15/12; rotary-body aspects in general F16C13/00, F16C15/00) · CPC title

• H02P25/062 Primary

  of the induction type · CPC title

• H02K47/22

  Single-armature frequency converters with or without phase-number conversion · CPC title

• H02K7/025 Primary

  for power storage · CPC title