Flywheel systems with multiple generator coils
Flywheel systems with multiple generator coils are provided with a rotor disk configured to rotate about a rotational axis; a plurality of magnets disposed in the rotor disk, the plurality of magnets angularly distributed around the rotational axis, and the plurality of magnets magnetically aligned such that respective magnetic north poles of each magnet of the plurality of magnets face a same direction; and a coil disposed adjacent to the rotor disk, the coil extending axially away from the rotor disk, and the coil positioned to sequentially overlap each magnet of the plurality of magnets in response to rotation of the rotor disk about the rotational axis.
1 . A device comprising:
a rotor disk configured to rotate about a rotational axis;
a plurality of magnets disposed in the rotor disk, the plurality of magnets angularly distributed around the rotational axis; and
a coil disposed adjacent to the rotor disk, the coil extending axially away from the rotor disk, and the coil positioned to sequentially overlap each magnet of the plurality of magnets in response to rotation of the rotor disk about the rotational axis, wherein the coil is positioned to overlap with a single magnet of the plurality of magnets on the rotor disk at any given time to be within a magnetic gap threshold of the one single magnet.
2 . A system comprising:
one or more rotor disks configured to rotate about a rotational axis, wherein each of the one or more rotor disks includes a respective plurality of magnets angularly distributed about the rotational axis;
a plurality of coils, each respective coil of the plurality of coils positioned to overlap with a single magnet of the plurality of magnets on a respective rotor disk of the one or more rotor disks at any given time to be within a magnetic gap threshold of the single magnet, the respective coil extending axially from a proximal end of the respective coil facing the respective disk to a distal end of the respective coil opposite the proximal end in a direction parallel to the rotational axis;
a load bus configured to transport electrical power;
a plurality of switches, each of the plurality of switches having a respective switch output that is electrically connected to the load bus; and
a controller coupled to the plurality of switches and configured to selectively connect at least one of the plurality of coils to the load bus by operating the plurality of switches.
3 . The system of claim 2 , wherein the controller is configured to select the at least one of the plurality of coils based on one or more of:
measurements of load level at the load bus;
expected characteristics of a load connected to the load bus;
predetermined characteristics of the plurality of coils; and
a time-of-day.
4 . The system of claim 2 , further comprising a converter disposed between the load bus and at least one of the plurality of switches to convert Alternating Current (AC) current output from at least one of the plurality of coils into a Direct Current (DC) current input into the load bus.
5 . The system of claim 2 , wherein the respective plurality of magnets for each of the one or more rotor disks includes magnets that are aligned so that magnetic north poles of the magnets each face a same direction, and wherein the one or more rotor disks comprise a first rotor disk and a second rotor disk that are configured to rotate at a shared rotational speed about the rotation axis.
6 . The system of claim 2 , further comprising a plurality of magnetic cores each magnetic core of the plurality of magnetic cores disposed inside a respect coil of the plurality of coils.
7 . The system of claim 6 , further comprising a wall disposed outside and adjacent to the plurality of coils, the wall formed from a magnetic material, wherein the wall and the plurality of magnetic cores have a same magnetic permeability.
8 . The system of claim 2 , further comprising:
a plurality of stator magnets each stator magnet disposed adjacent to a respective coil of the plurality of coil and extending from the proximal end to the distal end, wherein a first magnetic pole of the stator magnet is at the proximal end facing the respective rotor disk.
9 . The system of claim 8 , wherein each stator magnet of the plurality of stator magnets is aligned such that the first magnetic pole has a same polarity as respective magnetic poles of the plurality of magnets that face the plurality of coil during rotation of the respective rotor disk about the rotational axis.
10 . The system of claim 8 , wherein the each stator magnet of the plurality of stator magnets has a round shape at the proximal end facing the respective rotor disk.
11 . The system of claim 2 , further comprising:
a stator disposed adjacent to the rotor disk, the stator shaped to receive and support the plurality of coils, and the stator positioned to define the magnetic gap distance between the plurality of coils and the rotor disk while the rotor disk is rotating about the rotational axis.
12 . The system of claim 11 , wherein the stator is a stator disk extending around the rotational axis.
13 . The system of claim 11 , wherein the stator flexibly mounts the plurality of coils relative to the respective rotor disk to vary the magnetic gap distance in response to movement of the plurality of coils during rotation of the respective rotor disk about the rotational axis.
14 . The system of claim 2 , wherein a first coil of the plurality of coils is electrically connected in series with a second coil of the plurality of coils, wherein the first coil and the second coil are arranged on one side of the respective rotor risk.
15 . The system of claim 2 , wherein a first coil of the plurality of coils is electrically connected in series with a second coil of the plurality of coils, wherein the first coil and the second coil are arranged on opposing sides of the respective rotor risk.
16 . The system of claim 2 , wherein a first coil of the plurality of coils is electrically connected in parallel with a second coil of the plurality of coils, wherein the first coil and the second coil are arranged on one side of the respective rotor risk.
17 . The system of claim 2 , wherein a first coil of the plurality of coils is electrically connected in parallel with a second coil of the plurality of coils, wherein the first coil and the second coil are arranged on opposing sides of the respective rotor risk.
18 . A system, comprising:
a plurality of rotor disks, including:
a first rotor disk including a first plurality of magnets angularly distributed relative to a rotation axis;
a second rotor disk including a second plurality of magnets angularly distributed relative to the rotation axis;
a plurality of coils, including:
a first coil positioned to be within a magnetic gap distance of each magnet of the first plurality of magnets, wherein the first coil is positioned to overlap with a single magnet of the first plurality of magnets on the first rotor disk at any given time to be within the magnetic gap threshold of the single magnet of the first plurality of magnets; and
a second coil positioned to be within the magnetic gap distance of each magnetic of the second plurality of magnets, wherein second first coil is positioned to overlap with a single magnet of the second plurality of magnets on the second rotor disk at any given time to be within the magnetic gap threshold of the single magnet of the first plurality of magnets; and
wherein the first rotor disk and the first coil are positioned relative to the second rotor disk and the second coil to sequentially overlap the first plurality of magnets with the first coil relative to overlapping the second plurality of magnets with the second coil while rotating the first rotor disk and the second rotor disk at shared rotational speed about the rotation axis.
19 . The system of claim 18 , wherein each magnet of the first plurality of magnets is positioned with a non-zero angular offset relative to a corresponding magnetic from the second plurality of magnets, and wherein the first coil fully overlaps the second coil.
20 . The system of claim 18 , wherein each magnetic of the first plurality of magnets is positioned to fully overlap a corresponding magnet from the second plurality of magnets and the first coil is positioned with a non-zero angular offset relative to the second coil.
21 . The system of claim 19 , further comprising:
a third coil that fully overlaps the first coil and is positioned to be within the magnetic gap distance of each magnetic of the second plurality of magnets;
wherein the first coil is wired in series with the second coil and is connected to a load bus via a first switch, different from a second switch that connects the third coil to the load bus.