Method and system for rapid starting of a combustion engine in a multi-engine aircraft
A starting and electrical generation system for a main engine. A starter-generator comprises a first polyphase winding and a second polyphase winding jointly setting in motion a transmission shaft in a start mode, the starting and electrical generation system comprising a first main electrical power source connected on command by a first electrical connection to at least one first main electrical converter electrically connected to the first winding and a second main electrical power source connected on command by a second electrical connection to at least one second main electrical converter electrically connected to the second winding.
1 . A starting and electrical generation system for a main combustion engine of an aircraft, the starting and electrical generation system comprising a starter-generator provided with a transmission shaft, the starter-generator being operable in a motor mode for setting in motion a main moving assembly of the main combustion engine with the transmission shaft, and a generator mode for generating electrical power by having the transmission shaft set in motion by the main moving assembly, the starter-generator comprising a first winding that is polyphase and a second winding that is polyphase generating magnetic fields to create respective motor torques jointly setting in motion the transmission shaft in a starting mode of the motor mode, the starting and electrical generation system comprising a first main electrical power source connected on command by a first electrical connection to at least one first main electrical converter electrically connected to the first winding, and a second main electrical power source connected on command by a second electrical connection to at least one second main electrical converter electrically connected to the second winding,
wherein the starting and electrical generation system comprises a manager configured to:
in the starting mode, electrically power the first winding via the first main electrical converter with at least the first main electrical power source, electrically power the second winding via the second main electrical converter with at least the second main electrical power source;
in a standby mode, power one of the first winding and second winding with the second main electrical power source, maintaining the first main electrical power source under load via a transverse electrical connection connected to the second electrical connection; and
in an electrical power production mode, electrically connect, in parallel, the second main electrical converter and the first main electrical converter to electrically power the first main electrical power source.
2 . The starting and electrical generation system according to claim 1 ,
wherein the first main electrical power source is not voltage regulated and the second main electrical power source is voltage regulated or the first main electrical power source and the second main electrical power source are regulated to different voltages.
3 . The starting and electrical generation system according to claim 1 ,
wherein the first main electrical power source comprises at least one electric battery or one thermal battery or one supercapacitor.
4 . The starting and electrical generation system according to claim 1 ,
wherein the second main electrical power source comprises a voltage-regulated electrical generator that is configured to be mechanically set in motion by a mechanical system.
5 . The starting and electrical generation system according to claim 1 ,
wherein the starter-generator comprises an electrical machine having a stator provided with the first winding and the second winding that are polyphase, with floating neutral and galvanically insulated from each other, the electrical machine comprising a rotor with buried permanent magnets, having variable reluctance and constrained to rotate with the transmission shaft.
6 . The starting and electrical generation system according to claim 1 ,
wherein the starter-generator includes a dual electrical machine with separate excitations, the dual electrical machine with separate excitations comprising a stator provided with the first winding and the second winding, the dual electrical machine with separate excitations comprising a rotor provided with two rotor windings that are electrically connected to an electrical brush commutator.
7 . The starting and electrical generation system according to claim 1 ,
wherein the starter-generator comprises a magnet starter and an electrical machine operating in generator mode and in motor mode, the magnet starter being provided with a first stator having the first winding and with a first rotor that is mechanically connected to the transmission shaft by a freewheel, the electrical machine comprising a second stator provided with the second winding and with a second rotor integral with the transmission shaft, the electrical machine being able to be an electrical machine with separate or asynchronous excitation.
8 . The starting and electrical generation system according to claim 1 ,
wherein the starter-generator comprises a dual asynchronous electrical machine comprising a stator provided with the first winding and the second winding.
9 . The starting and electrical generation system according to claim 1 ,
wherein the starter-generator comprises a separately excited electrical machine comprising a stator having one of the first winding and the second winding, and an asynchronous electrical machine comprising a stator having the other of the first winding and the second winding.
10 . The starting and electrical generation system according to claim 1 ,
wherein the second electrical connection comprises a main bus, and the manager comprises:
a controller;
a first main contactor commanded by the controller and arranged on the first electrical connection; and
a second main contactor commanded by the controller and arranged on the second electrical connection between the main bus and the second main electrical converter.
11 . The starting and electrical generation system according to claim 10 ,
wherein the manager comprises:
a third main contactor commanded by the controller and arranged between the main bus and a connection configured to be electrically connected to a complementary electrical connection of an additional electrical circuit;
a fourth main contactor commanded by the controller and arranged on the transverse electrical connection, the transverse electrical connection extending from the second electrical connection to the first electrical connection between the first main contactor and the first main electrical power source; and
a fifth main contactor commanded by the controller and arranged on an electrical line connecting the first electrical connection and the second electrical connection between, firstly, the second main contactor and the second main electrical converter and, secondly, between the first main contactor and the first main electrical converter.
12 . An aircraft provided with a main combustion engine and with at least one additional combustion engine connected to a mechanical system setting in motion at least one rotary wing or one rotor or one propeller, the additional combustion engine being connected to an additional electrical machine that can operate according to a motor mode for setting in motion an additional moving assembly of the additional combustion engine and a generator mode for generating electrical power by being set in motion by the additional moving assembly, the additional electrical machine being electrically connected to an additional electrical converter that is connected by an additional electrical connection to an additional electrical power source,
wherein the aircraft comprises the starting and electrical generation system according to claim 1 for the main combustion engine.
13 . The aircraft according to claim 12 ,
wherein the mechanical system comprises a gearbox connected to the main combustion engine and to the additional combustion engine, and the second main electrical power source is set in motion by the gearbox.
14 . A method for starting a combustion engine and generating electrical power with the starting and electrical generation system according to claim 1 ,
wherein the method comprises:
the starting mode comprising the following steps: electrically powering the first winding via the first main electrical converter with at least the first main electrical power source, electrically powering the second winding via the second main electrical converter with at least the second main electrical power source;
the starting standby mode comprising the following steps: powering one of the first winding and second winding with the second main electrical power source and maintaining the first main electrical power source under load via the transverse electrical connection connected to the second electrical connection; and
the electrical power production mode comprising the following steps: electrically connecting, in parallel, the second main electrical converter and the first main electrical converter and connecting the second main electrical converter and the first main electrical converter to the first main electrical power source.
15 . A starting and electrical generation system for a main combustion engine of an aircraft, the starting and electrical generation system comprising:
a starter-generator having a transmission shaft, the starter-generator being configured to operate in a motor mode in which the transmission shaft transmits torque to a main moving assembly of the main combustion engine, and a generator mode in which electrical power is generated when the transmission shaft is driven by the main moving assembly, the starter-generator comprising a first polyphase winding and a second polyphase winding, each configured to generate electromagnetic torque, the torques collectively driving the transmission shaft during a starting operation, the starting and electrical generation system comprising a first main electrical power source selectively connectable by a first electrical connection to a first main electrical converter electrically connected to the first polyphase winding, and a second main electrical power source selectively connectable by a second electrical connection to a second main electrical converter electrically connected to the second polyphase winding,
wherein the starting and electrical generation system comprises control circuitry including a controller and switching elements, the control circuitry being configured such that:
during operation in a starting mode, the control circuitry causes electrical power from the first main electrical power source to be supplied to the first polyphase winding via the first main electrical converter, and causes electrical power from the second main electrical power source to be supplied to the second polyphase winding via the second main electrical converter;
during operation in a standby mode, the control circuitry causes electrical power from the second main electrical power source to be supplied to one of the first polyphase winding and second polyphase winding, and causes the first main electrical power source to be maintained under load via a transverse electrical connection connected to the second electrical connection; and
during operation in an electrical power production mode, the control circuitry causes the first main electrical converter and the second main electrical converter to be electrically connected in parallel to supply electrical power to the first main electrical power source.
16 . The starting and electrical generation system of claim 15 , wherein the switching elements comprise one or more electrically actuated contactors arranged to selectively open and close the first electrical connection and the second electrical connection.
17 . The starting and electrical generation system of claim 15 , wherein the main moving assembly comprises one or more compression turbines mechanically coupled in rotation to one or more expansion turbines of the main combustion engine.
18 . An aircraft comprising the starting and electrical generation system of claim 15 , the aircraft further comprising:
an additional combustion engine coupled to a power transmission system configured to drive at least one of a rotary wing, a rotor, or a propeller; and
an additional electrical machine coupled to the additional combustion engine and configured to operate (i) in a motor mode in which the additional electrical machine applies torque to an additional rotating assembly of the additional combustion engine and (ii) a generator mode in which the additional electrical machine generates electrical power when driven by the additional rotating assembly, wherein the additional electrical machine is electrically coupled by an additional electrical converter, and wherein the additional electrical converter is coupled by an additional electrical connection to an additional electrical power source.
19 . The starting and electrical generation system of claim 18 , wherein the power transmission system comprises a gearbox mechanically coupled to the main combustion engine and the additional combustion engine.
20 . The starting and electrical generation system of claim 18 , wherein the additional rotating assembly comprises one or more compression turbines mechanically coupled in rotation to one or more expansion turbines of the additional combustion engine.