Power limiting generator control unit (gcu)

Patent metadata

Field	Value
Publication number	US-2016332740-A1
Application number	US-201615151935-A
Country	US
Kind code	A1
Filing date	May 11, 2016
Priority date	May 11, 2015
Publication date	Nov 17, 2016
Grant date	—

Abstract

A method of operating an electrical system of an aircraft is provided. The method includes initiating a cross-start action for cross-starting a non-operative engine using a generator of an operative engine, entering a power limiting mode of a generator control unit (GCU) of the operative engine, remaining in the power limiting mode for a duration of the cross-start action and returning to the non-power limiting mode of the GCU of the operative engine upon completion of the cross-start action.

First claim

What is claimed is:

1 . A method of operating an electrical system of an aircraft, the method comprising:
initiating a cross-start action for cross-starting a non-operative engine using a generator of an operative engine; entering a power limiting mode of a generator control unit (GCU) of the operative engine; remaining in the power limiting mode for a duration of the cross-start action; and returning to the non-power limiting mode of the GCU of the operative engine upon completion of the cross-start action.

2 . The method according to claim 1 , wherein the entering of the power limiting mode comprises:
reducing an amount of power that can be pulled off of the operative engine; and deriving from a battery associated with the operative engine any additionally needed power for the cross-start action exceeding power that can be drawn from the operative engine.

3 . The method according to claim 1 , further comprising load dumping during the duration of the cross-start action.

4 . The method according to claim 1 , further comprising deriving power from an auxiliary power unit (APU) for the cross-start action.

5 . The method according to claim 1 , wherein a secondary method comprises recharging a depleted battery.

6 . The method according to claim 5 , wherein the secondary method comprises:
registering a return to a normal non-power limited GCU mode; calculating a recharging time; entering a secondary power limiting GCU mode in response to the registration; remaining in the secondary power limiting GCU mode for a recharging duration; and returning to a normal non-power limited GCU mode upon completion of the recharging.

7 . The method according to claim 5 , further comprising load dumping during the duration of the cross-start action.

8 . The method according to claim 5 , further comprising deriving power from an auxiliary power unit (APU) for the cross-start action

9 . The method according to claim 1 , further comprising discretely reducing a generator voltage to maintain a generator power output limit.

10 . The method according to claim 9 , further comprising discretely reducing a generator voltage from about 28 volts to as low as 16 volts and from 16 volts to as low as 10 volts.

11 . The method according to claim 1 , further comprising gradually reducing a generator voltage to maintain a generator power output limit.

12 . An aircraft, comprising:
an airframe; main and tail rotors disposed on the airframe; engines supportively disposed on the airframe to drive rotations of the main and tail rotors; and an electrical system configured to initiate a cross-start action for cross-starting a non-operative one of the engines using a generator of an operative one of the engines, to enter a power limiting mode of a generator control unit (GCU) of the operative engine, to remain in the power limiting mode for a duration of the cross-start action and to return to the non-power limiting mode of the GCU of the operative engine upon completion of the cross-start action.

13 . The aircraft according to claim 12 , wherein the entry of the power limiting mode by the electrical system comprises reducing an amount of power that can be pulled off of the operative engine and deriving from a battery associated with the operative engine any additionally needed power for the cross-start action exceeding power that can be drawn from the operative engine.

14 . The aircraft according to claim 12 , wherein the electrical system is further configured to recharge a depleted battery.

15 . The aircraft according to claim 14 , wherein the recharging comprises registering a return to a normal non-power limited GCU mode, calculating a recharging time, entering a secondary power limiting GCU mode in response to the registration, remaining in the secondary power limiting GCU mode for a recharging duration and returning to a normal non-power limited GCU mode upon completion of the recharging.

Assignees

• Sikorsky Aircraft Corp

Inventors

• Eisenhauer Mark P
• Bourne Frederick L
• Fogarty Matthew

Classifications

• F02N11/0866 Primary

  comprising several power sources, e.g. battery and capacitor or two batteries · CPC title

• B64D2041/005

  Fuel cells · CPC title

• B64D31/12 Primary

  for equalising or synchronising power plants · CPC title

• F02N2200/06

  said parameters being related to the power supply or driving circuits for the starter · CPC title

• F02C9/00 Primary

  Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants (controlling air intakes F02C7/057; controlling turbines F01D; controlling compressors F04D27/00; controlling in general G05) · CPC title