Rotorcraft having electrical equipment for regulating electrical power supply to an engine on starting

• US 10,124,903 B2
• Filed: 01/07/2016
• Issued: 11/13/2018
• Est. Priority Date: 01/08/2015
• Status: Active Grant

• Current Assignee: Airbus Helicopters
• Original Assignee: Airbus Helicopters
• Inventors: Jamot, Michel
• Primary Examiner(s): Le, Dinh T
• Application Number:
  US14/989,827
• Publication Number:
  US 20160200444A1
• Time in Patent Office: 1,041 Days
• Field of Search: 60778, 60786, 60 3913, 244 53 A, 307 10, 307 106
• CPC Class Codes: B64C 27/12 Rotor drives
• CPC Class Codes: B64D 31/02 Initiating means
• CPC Class Codes: F01D 19/00 Starting of machines or engines; Regulating, controlling, or safety means in connection therewith warming-up before starting F01D25/10; turning or inching gear F01D25/34
• CPC Class Codes: F02C 7/275 Mechanical drives
• CPC Class Codes: F05D 2220/329 in helicopters
• CPC Class Codes: H02J 2310/44 for aircrafts
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A rotorcraft having at least one turboshaft engine with an electric starter powered from the onboard network that makes use of a battery and of a discharge module made up of a plurality of discharge members connected in series. An electric circuit comprises a regulator device for regulating a main bidirectional DC-DC static converter connected in series with the discharge module. The regulator device maintains equivalence between the current of the electric circuit and the current of the onboard network, regardless of the mode of operation of the discharge module, and does so by monitoring the voltage of the discharge module and the voltage of the onboard network.

Claims

1. A rotorcraft having an electric circuit and at least one turboshaft engine comprising a gas compressor and a turbine, the engine being provided with a starter for driving the gas compressor while starting the engine, the electric circuit being connected via a connection bus to an onboard electricity network for delivering DC to operate the starter under dependency of the electric circuit, the onboard electricity network being maintained at a setpoint voltage during starting by regulating the delivery of electrical energy to the starter by the electric circuit from a main source of electrical energy and a secondary source of electrical energy, the main source of electrical energy for delivering DC to the onboard network, the secondary source operable in first and second modes depending on a bidirectional DC-DC converter:

wherein the first mode is a “

discharge”

mode of operating the secondary source in which the bidirectional DC-DC converter controls the delivery of electrical energy from the secondary source as a function of a value of at least one parameter identifying progress in starting the engine, such that additional electrical energy is delivered by the secondary source to the onboard network while starting the engine to supplement the electrical energy supplied to the onboard network by the main source; and

wherein the second mode is a “

recharging”

mode of operating the secondary source in which the bidirectional DC-DC converter regulates recharging of the secondary source from the onboard network with electrical energy supplied by the main source;

the secondary source of the electric circuit is connected in parallel with the main source, wherein the secondary source comprises a discharge module having a plurality of discharge members that are connected in series;

the discharge module being connected in series with the electric circuit via the bidirectional DC-DC converter;

the bidirectional DC-DC converter being a main static converter comprising at least an electrical power architecture and an N phase chopper with phases mutually shifted by 2π

/N; and

a regulator device comprises a primary regulation loop and controls the operation of the electrical power architecture of the main static converter, at least by maintaining current equivalence between a current of the electric circuit and a current of the onboard network, regardless of the mode of operation of the discharge module and by monitoring the voltage of the discharge module and the voltage of the onboard network.

2. A rotorcraft according to claim 1, wherein the regulator device includes secondary regulation loops in addition to the primary regulation loop that controls the current as a function of the secondary regulation loops respectively identifying at least the voltage of the onboard network and the voltage of the discharge module.

3. A rotorcraft according to claim 1, wherein the electric circuit includes a bistable for selectively activating the discharge mode and activating the recharging mode of the discharge module by means of the main static converter, the bistable spontaneously being in a first position for activating the recharging mode and being controlled to take up a second position for activating the discharging mode on receiving data relating to activating engine starting.

4. A rotorcraft according to claim 2, wherein in recharging mode, the primary regulation loop is controlled by a first secondary regulation loop regulating the voltage of the discharge module.

5. A rotorcraft according to claim 2, wherein in discharging mode, the primary regulation loop is controlled by a second secondary regulation loop complying with a reference voltage to regulate the voltage of the electricity delivered by the electric circuit to the onboard network via the connection bus, the primary regulation loop maintaining the onboard network at a voltage suitable for enabling the starter to be operated at a required torque for driving the turbine as a function of the value of the at least one parameter identifying progress in starting the engine.

6. A rotorcraft according to claim 5, wherein the reference voltage is a predefined fixed value identified depending on the required torque to be developed by the starter for driving the turbine and starting the engine.

7. A rotorcraft according to claim 5, wherein the reference voltage is identified by a third secondary regulation loop taking account equally well of the torque and/or the speed of rotation of the starter at an instant under consideration and/or the current delivered to the starter by the onboard network.

8. A rotorcraft according to claim 1, wherein the regulator device includes a function of inhibiting the chopper providing a voltage of the discharge module is in compliance with a voltage lying within a predetermined range of acceptable values.

9. A rotorcraft according to claim 1, wherein the N phase chopper of the main static converter has N phases constituted by static power switches operated in interleaved mode.

10. A rotorcraft according to claim 1, wherein the N phase chopper of the main static converter has N phases constituted by staged high frequency transformers with electrical isolation being interposed between the discharge module and the connection bus.

11. A rotorcraft according to claim 1, wherein another bidirectional DC-DC static converter constituting a secondary static converter is interposed between the main source and the onboard network;

the secondary static converter regulating a voltage of electricity delivered by the main source to be in compliance with a setpoint voltage of the onboard electricity network.

12. A rotorcraft according to claim 1, wherein the discharge module and the main static converter are grouped together in a common first electrical component.

13. A rotorcraft according to claim 1, wherein the regulator device and the main static converter are incorporated in a common second electrical component.

14. A rotorcraft according to claim 1, wherein the discharge module, the main static converter, and the regulator device are grouped together in a common piece of electrical equipment.

15. A rotorcraft according to claim 1, wherein the at least one parameter identifying progress in the stage of starting the engine is any one of at least the following parameters:

at least one parameter identifying the speed of rotation of the starter and/or the speed at which the turbine is driven in rotation;

a parameter identifying the resisting torque opposed by the turbine against being rotated by the starter; and

a parameter identifying the current delivered to the starter by the onboard network.

16. A rotorcraft comprising:

at least one turboshaft engine with a gas compressor and a turbine, the engine provided with a starter configured to drive the gas compressor while starting the engine;

an onboard electricity network configured to deliver DC to operate the starter;

a main source of electrical energy and a secondary source of electrical energy connected to the onboard electricity network, the secondary source being connected in parallel with the main source, the secondary source comprising a discharge module having a plurality of discharge members that are connected in series; and

an electric circuit connected to the onboard electricity network via a connection bus, the electric circuit delivering DC to operate the starter under a dependency of the electric circuit by regulating the delivery of electrical energy to the starter from the main source and the secondary source to maintain the onboard electricity network at a setpoint voltage during starting;

wherein the electrical circuit comprises a bidirectional DC-DC converter and a regulator device,

wherein the bidirectional DC-DC circuit has a discharge mode and a recharging mode associated with the secondary source, wherein the discharge module of the secondary source is connected in series with the electric circuit via the bidirectional DC-DC converter;

wherein the bidirectional DC-DC converter is provided by a main static converter comprising at least an electrical power architecture and an N phase chopper with phases mutually shifted by 2π

/N;

wherein the bidirectional DC-DC converter operates in the discharge mode to control delivery of electrical energy from the secondary source to the onboard electricity network as a function of a value of at least one parameter identifying progress in starting the engine, and such that additional electrical energy is delivered by the secondary source to the onboard network while starting the engine to supplement the electrical energy supplied to the onboard network by the main source;

wherein the bidirectional DC-DC converter operates in the recharging mode to regulate recharging of the secondary source from the onboard network with electrical energy supplied by the main source; and

wherein the regulator device comprises a primary regulation loop and controls the operation of the electrical power architecture of the main static converter, at least by maintaining current equivalence between a current of the electric circuit and a current of the onboard network, regardless of the mode of operation of the discharge module and by monitoring the voltage of the discharge module and the voltage of the onboard network.

17. The rotorcraft of claim 16 wherein the at least one parameter identifying progress in the stage of starting the engine includes a parameter identifying the speed of rotation of the starter and/or the speed at which the turbine is driven in rotation.

18. The rotorcraft of claim 16 wherein the at least one parameter identifying progress in the stage of starting the engine includes a parameter identifying the resisting torque opposed by the turbine against being rotated by the starter.

19. The rotorcraft of claim 16 wherein the at least one parameter identifying progress in the stage of starting the engine includes a parameter identifying the current delivered to the starter by the onboard network.

20. The rotorcraft of claim 16 wherein the regulator device further comprises secondary regulation loops to control the current as a function of the secondary regulation loops respectively identifying a voltage of the onboard network and a voltage of the discharge module.