Patent ID: 11929619
Assignee: RAYTHEON COMPANY
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 18:
19. An energy storage power source, comprising:
a wound-rotor induction machine (WRIM) including a primary winding wound 360 degrees around a stationary magnetic core, a secondary winding wound 360 degrees around a rotating magnetic core separated from the stationary magnetic core by a radial airgap and coupled to a load producing output and N tertiary windings each wound 360/N degrees around the stationary magnetic core, 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 rotor shaft that is coupled to the rotating magnetic core;
a flywheel coupled to the rotor shaft;
a prime mover configured to rotate the rotor shaft and supply motive power to the WRIM;
an AC capacitor bank coupled to the primary winding;
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 energy storage elements;
a WRIM controller,
wherein in one or more charging states, the prime mover rotates the shaft to magnetize the radial airgap with reactive excitation supplied by the AC capacitor bank to self-excite the WRIM, said AC capacitor bank providing a leading power-factor reactive power to balance the lagging power-factor reactive power required to magnetize the radial airgap and leakage inductances of the prime and tertiary windings on the stationary magnetic core and to excite the tertiary windings to provide controlled power through the AC/DC converters to selectively charge the N ESEs or to create torque to charge the flywheel; and
wherein in one or more discharge states, at least some capacity of the N ESEs are discharged back through the AC/DC converters to excite the tertiary windings to create a revolving magnetic field to magnetize the radial airgap and to supply real power to the rotating magnetic core 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 multiplied by the respective step-up transformation ratios and deliver a portion of the N ESEs energy capacity as electrical energy to the load producing output or the flywheel discharges energy through the secondary winding to the load producing output.