Energy storage power source using a wound-rotor induction machine (WRIM) to charge and discharge energy storage elements (ESEs)

Patent metadata

Field	Value
Publication number	US-12136844-B2
Application number	US-202117557758-A
Country	US
Kind code	B2
Filing date	Dec 21, 2021
Priority date	Dec 21, 2021
Publication date	Nov 5, 2024
Grant date	Nov 5, 2024

Abstract

A stored energy power source uses a wound-rotor induction machine (WRIM) to receive energy from an external source, store the energy in N energy storage elements (ESEs) via tertiary windings, and discharge the ESEs to deliver energy via a secondary winding to a load producing output. Each discharging ESE contributes to a total flux at the secondary winding to sum the individual ESEs voltages. These voltages can be stepped up or down by a transformation ratio between the secondary winding and each of the tertiary windings. A flywheel may be coupled to the secondary to store and delivery energy. Load factor power control can be used to stabilize the output voltage. The source may be configured to allow for the bi-directional flow of energy between an external power source, the ESEs, the flywheel and the load. The WRIM provides a safe, reliable and efficient system to provide high-level AC and DC output voltages.

First claim

I claim:

1. An energy storage power source, comprising:
a machine input configured to receive a variable AC input voltage Vin at a variable frequency;
a wound-rotor induction machine (WRIM) including a primary winding that is wound 360 degrees around a first magnetic core and coupled to the input to receive the AC input voltage Vin, a secondary winding that is wound 360 degrees around a second magnetic core configured to rotate relative to the first magnetic core and coupled to a load producing output and N tertiary windings each wound 360/N and distributed around the first magnetic core and magnetically coupled to both the primary and secondary windings;
N energy storage elements (ESEs);
N bi-directional AC/DC converters that each couple one of the tertiary windings to a respective one of the ESEs; and
a WRIM controller,
wherein in a charging state, the AC input voltage is coupled to the primary winding to create a traveling magnetic field to provide relative rotation between the first and second magnetic cores and to magnetize the tertiary windings to provide power through the AC/DC converters to selectively charge one or more of the N ESEs; and
wherein in a discharge state, one or more of the N ESEs discharge energy back through the respective AC/DC converters to excite the respective tertiary windings to create a traveling magnetic field to magnetize an airgap to assist the relative rotation between the first and second magnetic cores and to individually contribute to a total machine magnetic flux to magnetize the secondary winding to induce an AC output voltage on the secondary winding proportional to the sum of the voltages from the discharging ESEs and deliver energy to the load producing output.

2. The energy storage power source of claim 1 , further comprising:
an AC/AC converter that is configured to receive an AC voltage at a fixed frequency f 1 from an external AC power source and convert that AC voltage into the variable AC input voltage at variable frequency f 2 at the input.

3. The energy storage power source of claim 1 , further comprising:
a DC/AC converter that is configured to receive a DC voltage from an external DC power source and convert that DC voltage into the variable AC input voltage at variable frequency at the input.

4. The energy storage power source of claim 1 , wherein the AC output voltage is scaled by a transformation ratio determined by turns ratios of the secondary winding to the N tertiary windings.

5. The energy storage power source of claim 4 , wherein the transformation ratio is on average for all N ESEs greater than 1:1 to increase the AC output voltage.

6. The energy storage power source of claim 1 , wherein the load producing output is configured for a bi-directional flow of energy, wherein the WRIM is configured to selectively receive energy from the load producing output to charge the ESEs.

7. The energy storage power source of claim 6 , further comprising:
a flywheel coupled to the second magnetic core, said flywheel configured to selectively store energy from the AC input voltage, the ESEs or the load producing output via the secondary winding and to selectively deliver energy to at least the ESEs and the load producing output via the secondary winding.

8. The energy storage power source of claim 6 , wherein the machine energy input is configured for a bi-directional flow of energy, wherein the WRIM is configured to receive energy from the load producing output and deliver the energy back to the input.

9. The energy storage power source of claim 1 , wherein the N ESEs are electrically isolated from each other and the primary, secondary and N tertiary windings are electrically isolated from each other.

10. The energy storage power source of claim 1 , wherein a primary-to-tertiary turns ratio Np/Nt(i) for i=1 to N is independently configured to deliver a specified DC voltage VDC(i) to each of the N ESEs.

11. The energy storage power source of claim 1 , wherein the N bi-directional AC/DC converters are independently controllable to selectively charge one or more ESEs exclusively or (XOR) independently controllable to selectively discharge the one or more ESEs.

12. The energy storage power source of claim 1 , wherein the primary winding is segmented into M primary windings, each primary winding is coupled to a respective machine energy input to receive the AC input voltage, each primary winding is magnetically coupled to one or more of the tertiary windings, wherein the WRIM controller is configurable to simultaneously charge one or more ESEs coupled to a first subset of the M primary windings and to discharge one or more ESEs coupled to a second subset of the M primary windings in which the first and second subsets do not overlap.

13. The energy storage power source of claim 1 , further comprising:
a load factor power controller coupled to the load producing output to modulate an inductive-resistive load to actively adjust a power factor of the WRIM to vary a rotational speed and maintain the AC output voltage within a specified tolerance of a target voltage.

14. The energy storage power source of claim 1 , further comprising:
a flywheel coupled to the second magnetic core to store energy and to deliver kinetic energy to the ESEs or the load producing output.

15. The energy storage power source of claim 14 , wherein the WRIM controller is configured to discharge one or more ESEs to deliver energy to the load producing output with a first time constant and decelerate the flywheel to deliver energy to the load producing output at a second time constant wherein the second time constant is longer than said first time constant.

16. The energy storage power source of claim 1 , wherein in the discharging state the WRIM controller is configured to selectively decouple the AC input voltage from the primary winding.

17. The energy storage power source of claim 1 , wherein in the discharging state the WRIM controller is configured to leave the AC input voltage coupled to the primary winding to deliver additional energy via the secondary winding to the load producing output.

18. An energy storage power source, comprising:
a machine input configured to receive a variable AC input voltage Vin at a variable frequency;
a wound-rotor induction machine (WRIM) including a primary winding that is wound 360 degrees around a first magnetic core and coupled to the input to receive the AC input voltage Vin, a secondary winding that is wound 360 degrees around a second magnetic core configured to rotate relative to the first magnetic core and coupled to a load producing output and N tertiary windings each wound 360/N and distributed around the first magnetic core and magnetically coupled to both the primary and secondary windings, wherein a turns ratio of a number of secondary turns Ns to a number of tertiary turns Nt(i) i=1 to N defines an average step-up transformation ratio greater than one;
a flywheel mechanically coupled to the second magnetic core;
N energy storage elements (ESEs) that are electrically isolated from each other;
N bi-directional AC/DC converters that each couple one of the tertiary winding to a respective one of the ESEs; and
a WRIM controller,
wherein in one or more charging states, the AC input voltage is coupled to the primary winding to create a traveling magnetic field to provide the relative rotation between the first and second magnetic cores and to magnetize the tertiary windings to provide power through the AC/DC converters to selectively charge one or more of the N ESEs or to magnetize the s

Assignees

• Raytheon Co

Inventors

• Kuznetsov Stephen B

Classifications

• H02J7/50 Primary

  acting upon multiple batteries simultaneously or sequentially · CPC title

• H02J7/02

  for charging batteries from AC mains by converters · CPC title

• H02P2207/01

  Asynchronous machines · CPC title

• H02J2207/20

  Charging or discharging characterised by the power electronics converter · CPC title

• H02K7/025

  for power storage · CPC title