On-pulse transition times for pulsed controlled electric machines using boost voltages
AssigneeTula eTechnology, Inc.
InventorPaul Carvell
Life of this patent
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Abstract
Various boost circuits that are used to improve or reduce the time needed to transition an electric machine from an off-state to an on-state at the start of a next pulse during pulsed controlled operation. With these various boost circuits, the naturally generated Back Electromotive Force or “BEMF” that is induced when an electrical machine transitions from the on state to the off state at the end of an on pulse is harvested, rectified, and stored on a storage device. The harvested energy is then made available to the electric machine as a “boost” voltage at the onset of the next on pulse, resulting in a reduced transition time from the off-state to the on-state.
Claims35
An apparatus, comprising:
- a power supply for providing a power supply voltage;
- an electric machine;
- a power converter couple between the power supply and the electric machine;
- a pulse controller configured to selectively operate the electric machine in a pulsed mode where a work output is generated during on pulses when the electric machine is in an on-state and little to no work output is generated when the electric machine is in an off-state between on pulses;
- and
- a boost circuit, coupled to the electric machine, the boost circuit configured to:
- (a) harvest and store energy in a storage device when Back Electromagnetic Force (BEMF) energy from the electric machine exceeds the power supply voltage when the electric machine is in the off-state between pulses or transitioning from the on-state to the off-state following the end of the on pulses, and
- (b) apply the stored energy from the storage device to the electric machine when transitioning from the off-state to the on-state at the onset of subsequent on pulses respectively.
An Externally Excited Synchronous Machine (EESM), comprising:
- a stator;
- a rotor having coils configured to be energized by an external current source;
- a stator converter coupled to the stator of the EESM;
- a rotor power converter couple to the rotor of the EESM;
- a power supply for providing a power supply voltage to the EESM;
- a pulse controller for selectively operating the EESM in a pulsed mode where a work output is generated during on pulses when the EESM is in an on-state and little to no work output is generated when the EESM is in an off-state between on pulses;
- and
- a boost circuit configured to:
- (a) harvest and store energy in a storage device when Back Electromagnetic Force (BEMF) energy from a field current of the rotor exceeds the power supply voltage when the EESM is in the off-state or transitioning from the on-state to the off-state following the end of on pulses, and
- (b) apply the stored energy from the storage device to the EESM when transitioning from the off-state to the on-state at the onset of the on pulses respectively.
Dependencies are inferred from the claim text.