No-break-power-transfer control system for variable frequency electrical power systems
AssigneeHoneywell International Inc.
InventorRay M. McGinley
Life of this patent
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Abstract
A method and apparatus for executing a no-break power transfer between an electrical power generator powered by an auxiliary power unit (APU) and an electrical power generator powered by an aircraft main engine. The method comprises sending a power transfer command, a load/unload amplitude signal, and a target frequency signal from a bus power control unit to an APU electronic control unit; deriving a calculated load range for the APU at a new load and frequency operating point; and determining if the new load and frequency operating point falls within the calculated APU load range. If within range, a no-break power transfer is initiated; if not within range, a power transfer with momentary interruption is initiated.
Claims35
A method for switching between an auxiliary power unit electrical power generator and a main engine electrical power generator, the auxiliary and main power generators connectable to an electrical bus, said method comprising the steps of:
- sending a new power source command to a bus power control unit;
- sending a load/unload amplitude signal and a target frequency signal from said bus power control unit to an auxiliary power unit electronic control unit;
- deriving a calculated load range for the auxiliary power unit electrical power generator;
- comparing said load/unload amplitude signal with said calculated load range;
- initiating a no-break power transfer when said load/unload amplitude signal falls within said calculated load range;
- and
- initiating a power transfer with momentary interruption when said load/unload amplitude signal does not fall within said calculated load range.
A method for transferring between a main engine electrical power generator and an auxiliary power unit electrical power generator to power an aircraft electrical system, said method comprising the steps of:
- deriving a calculated load range for the auxiliary power unit electrical power generator, said calculated load range being a function of auxiliary power unit electrical power generator operating conditions;
- comparing said calculated load range with a power requirement signal for the aircraft electrical system;
- initiating a no-break power transfer between the main engine electrical power generator and the auxiliary power unit electrical power generator when said power requirement signal falls within said calculated load range;
- and
- initiating a power transfer with momentary interruption between the main engine electrical power generator and the auxiliary power unit electrical power generator when said power requirement signal does not fall within said calculated load range.
A control apparatus suitable for use in an aircraft electrical power system having a main engine electrical power generator, an auxiliary power unit electrical power generator powered by an auxiliary power unit, and a bus power control unit receiving a main engine power signal from the main engine electrical power generator and an auxiliary power unit signal from the auxiliary power unit electrical power generator, said control apparatus comprising:
- a program file including an algorithm, said algorithm for deriving a calculated load range for the auxiliary power unit from an operating auxiliary power unit inlet air pressure reading, an auxiliary power unit inlet air temperature reading, an auxiliary power unit outlet air temperature reading, and an auxiliary power unit shaft rotational speed reading;
- and
- an electronic control unit for receiving a load/unload amplitude signal from the bus power control unit, said load/unload amplitude signal being a function of the main engine power signal and the auxiliary power unit signal, said electronic control unit further for obtaining said operating auxiliary power unit inlet air pressure reading, said auxiliary power unit inlet air temperature reading, said auxiliary power unit outlet air temperature reading, and said auxiliary power unit shaft rotational speed reading, said electronic control unit further for receiving said calculated load range from said program file and for generating a no-break power transfer confirmation signal.
A control apparatus suitable for use in an aircraft electrical power system having a main engine electrical power generator, an auxiliary power unit electrical power generator powered by an auxiliary power unit, and a bus power control unit receiving a main engine power signal from the main electrical power generation unit and an auxiliary unit power signal from the auxiliary electrical power generation unit, said control apparatus comprising:
- a load range database for deriving a calculated load range for the auxiliary power unit from an operating auxiliary power unit inlet air pressure reading, an auxiliary power unit inlet air temperature reading, an auxiliary power unit outlet air temperature reading, and an auxiliary power unit shaft rotational speed reading;
- and
- an electronic control unit for receiving a load/unload amplitude signal from the bus power control unit, said load/unload amplitude signal being a function of the main engine power signal and the auxiliary power unit signal, said electronic control unit further for obtaining said operating auxiliary power unit inlet air pressure reading, said auxiliary power unit inlet air temperature reading, said auxiliary power unit outlet air temperature reading and said auxiliary power unit shaft rotational speed reading, said electronic control unit further for receiving said calculated load range from said load range database and for generating a no-break power transfer confirmation signal.
An electrical power generation system suitable for use in an aircraft, said system comprising:
- a main engine electrical power generator powered by a main engine and controlled by a main engine generator control unit;
- an auxiliary power unit electrical power generator powered by an auxiliary power unit and controlled by a auxiliary power unit generator control unit;
- a bus power control unit for receiving a main engine power signal from said main engine electrical power generator and further for receiving an auxiliary power unit power signal from said auxiliary power unit electrical power generator;
- and
- an auxiliary power unit electronic control unit for monitoring operating auxiliary power unit inlet air pressure, said auxiliary power unit electronic control unit further for monitoring operating characteristics of said auxiliary power unit, wherein said auxiliary power unit electronic control unit comprises a load range database, said load range database including empirical data providing lookup output power values as a function of operating characteristics for said auxiliary power unit.
A computer readable medium having computer-executable instructions for performing a method for executing a power transfer between an auxiliary power unit electrical power generator and a main engine electrical power generator, wherein said method comprises the steps of:
- receiving a load/unload amplitude signal and a new power source command via a bus power control unit;
- deriving a calculated load range for the auxiliary power unit electrical power generator;
- comparing said load/unload amplitude signal with said calculated load range;
- sending a no-break power transfer confirm signal to said bus power control unit when said load/unload amplitude signal falls within said calculated load range;
- and
- sending a break power transfer confirm signal to said bus power control unit so as to initiate a power transfer with momentary interruption when said load/unload amplitude signal does not fall within said calculated load range.
An aircraft having a main engine and an auxiliary power unit, said aircraft comprising:
- a main engine electrical power generator connected to the main engine;
- an auxiliary power unit electrical power generator connected to the auxiliary power unit;
- a bus power control unit for receiving a main engine power signal from said main engine electrical power generator and further for receiving an auxiliary power unit power signal from said auxiliary power unit electrical power generator so as to produce a load/unload amplitude signal;
- and
- an auxiliary power unit electronic control unit for monitoring operating auxiliary power unit operating characteristics and deriving a calculated load range for said auxiliary power unit such that a no-break power transfer may be initiated if said load/unload amplitude signal Thus within said calculated load range.
Dependencies are inferred from the claim text.