METHOD AND SYSTEMS FOR AN ENGINE STARTER/GENERATOR
First Claim
1. A starter/generator system comprising:
- a three phase squirrel cage induction machine; and
a first three-phase inverter/converter/controller (ICC) unit operatively coupled to said three phase squirrel cage induction machine through a first electrical path, said ICC comprising;
a three phase inverter/converter electrically coupled to said three phase squirrel cage induction machine;
a bidirectional DC-DC converter electrically coupled to said three phase inverter/converter; and
a digital control board configured to sensorlessly determine a rotor angle from a plurality of phase currents to the induction machine during a start mode;
wherein during a start mode, logic in said digital control board configures said starter/generator system into a combination of an induction motor, a three phase DC-AC inverter, and a DC-DC boost converter, and during a generate mode, the logic in said digital control board configures said starter/generator system into a combination of an induction generator, a three phase AC-DC converter, and a DC-DC buck converter.
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Accused Products
Abstract
A method and system for an engine starter/generator is provided. The starter/generator system includes a three phase squirrel cage induction machine, a three phase inverter/converter electrically coupled to the three phase squirrel cage induction machine. The starter/generator system also includes a bidirectional DC-DC converter electrically coupled to the three phase inverter/converter, and a digital control board configured to sensorlessly determine a rotor angle from a plurality of phase currents to the induction machine during a start mode. During the start mode, logic in the digital control board configures the starter/generator system into a combination of an induction motor, a three phase DC-AC inverter, and a DC-DC boost converter, and during a generate mode, the logic in the digital control board configures the starter/generator system into a combination of an induction generator, a three phase AC-DC converter, and a DC-DC buck converter.
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Citations
20 Claims
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1. A starter/generator system comprising:
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a three phase squirrel cage induction machine; and a first three-phase inverter/converter/controller (ICC) unit operatively coupled to said three phase squirrel cage induction machine through a first electrical path, said ICC comprising; a three phase inverter/converter electrically coupled to said three phase squirrel cage induction machine; a bidirectional DC-DC converter electrically coupled to said three phase inverter/converter; and a digital control board configured to sensorlessly determine a rotor angle from a plurality of phase currents to the induction machine during a start mode; wherein during a start mode, logic in said digital control board configures said starter/generator system into a combination of an induction motor, a three phase DC-AC inverter, and a DC-DC boost converter, and during a generate mode, the logic in said digital control board configures said starter/generator system into a combination of an induction generator, a three phase AC-DC converter, and a DC-DC buck converter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of controlling an engine starter/generator system for starting an engine and generating power using the engine, said method comprising:
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during a start mode; boosting an input voltage using a DC-DC converter; inverting the boosted DC voltage into a three phase AC output that drives an induction motor configured to rotate the engine; measuring two of the three phase currents, ia and ib; converting phase currents, ia and ib into id and iq, where id is the current aligning with the rotor flux linkage and iq is the current perpendicular to the rotor flux linkage; controlling a field of an induction machine of the starter/generator system using id; controlling a torque of an induction machine of the starter/generator system using iq. during a generate mode; applying a three phase output of the induction machine to the input of a the three phase converter to generate a three phase AC voltage; converting the three phase AC voltage into a DC voltage at a first voltage magnitude greater than a predetermined output voltage magnitude of the starter/generator system; bucking the DC voltage down to the predetermined output voltage magnitude of the starter/generator system using a cascaded DC-DC converter. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A brushless starter/generator (BS/G) and accessory gearbox (AGB) assembly for starting an engine and generating electrical power from said engine, said BS/G/AGB assembly comprising:
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an induction electromagnetic machine comprising a squirrel cage rotor rotatable about an overhung gearbox shaft, a stator at least partially surrounding said rotor, and a housing enclosing said rotor and stator; an engine accessory gearbox (AGB) coupled coaxially to said overhung gearbox shaft; a dry cavity oil system configured to transfer heat generated in the BS/G to a lubricating oil system associated with the engine through at least one of convection and conduction to the AGB. - View Dependent Claims (18, 19, 20)
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Specification