Patent Application
20240426226
Exemplary embodiments of the present disclosure pertain to the art of hybrid engine systems having a thermal engine, such as a gas turbine engine that is operably connected to an electrical generator to generate electrical power to be used by an aircraft. The electrical power is used to power propulsion components and any other aircraft systems.
A fault in the generator can cause a near instantaneous loss of electrical power, which in turn can cause a near instantaneous electrical fault that can rapidly propagate through the propulsion system. A delay in detecting the loss of generator power can significantly damage the propulsion system.
Additionally, an abrupt reduction in load on the aircraft electrical grid may lead to a brief overvoltage, or may unload the gas turbine engine leading to an overspeed condition. Either response may shorten the useful service life, or may cause immediate damage to the propulsion system.
In one exemplary embodiment, a series hybrid propulsion system of an aircraft includes a gas turbine engine, an electrical generator operably connected to the gas turbine engine configured to generate electrical power from operation of the gas turbine engine, and one or more electrically-driven propulsors configured to provide propulsion for the aircraft, and an electrical power grid configured to distribute electrical power generated at least at the electrical generator to the one or more electrically-driven propulsors. A voltage regulator is positioned downstream of the electrical generator and is configured to take one or more actions to compensate for a loss of load on the generator.
Additionally or alternatively, in this or other embodiments the one or more actions includes applying an emergency load to the generator.
Additionally or alternatively, in this or other embodiments the emergency load is applied to the generator when the generator is disconnected from the power grid.
Additionally or alternatively, in this or other embodiments the emergency load is applied via a shunt circuit at the voltage regulator.
Additionally or alternatively, in this or other embodiments the loss of load is determined by measuring one of a current or a voltage at the generator.
Additionally or alternatively, in this or other embodiments the one or more actions includes applying a variable resistive load to the generator.
Additionally or alternatively, in this or other embodiments the variable resistive load is applied to the generator when one or more electrically-driven propulsors are disconnected from the electrical power grid.
Additionally or alternatively, in this or other embodiments the one or more electrically-driven propulsors includes a fan, and an electric motor configured to drive the fan.
Additionally or alternatively, in this or other embodiments a motor controller is configured to control operation of the electric motor.
Additionally or alternatively, in this or other embodiments an energy storage system is operably connected to the electrical power grid and is configured to store electrical power generated at the electrical generator.
In another exemplary embodiment, a method of operating a series hybrid propulsion system of an aircraft includes generating electrical power at an electrical generator via operation of a gas turbine engine operably connected to the electrical generator, and distributing the electrical power to an electrical power grid. One or more electrically-driven propulsors are operated from the electrical power provided to the electrical power grid to provide propulsion for the aircraft. The load on the electrical generator is abruptly reduced, and one or more actions are taken at a voltage regulator positioned downstream of the electrical generator to compensate for a loss of load on the generator.
Additionally or alternatively, in this or other embodiments the reduction in load on the electrical generator is due to the electrical generator being disconnected from the electrical power grid.
Additionally or alternatively, in this or other embodiments the one or more actions includes applying an emergency load to the generator.
Additionally or alternatively, in this or other embodiments the emergency load is applied via a shunt circuit at the voltage regulator.
Additionally or alternatively, in this or other embodiments the reduction of load is determined by measuring one of a current or a voltage at the generator.
Additionally or alternatively, in this or other embodiments the reduction in load on the electrical generator is due to one or more electrically-driven propulsors being disconnected from the electrical power grid.
Additionally or alternatively, in this or other embodiments the one or more actions includes applying a variable resistive load to the generator.
Additionally or alternatively, in this or other embodiments the one or more electrically-driven propulsors includes a fan, and an electric motor configured to drive the fan.
Additionally or alternatively, in this or other embodiments a motor controller is configured to control operation of the electric motor.
Additionally or alternatively, in this or other embodiments electrical power generated at the electrical generator is stored at an energy storage system operably connected to the electrical power grid.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring to
The generator 14 is connected to a power grid 18 of the aircraft, which may be an alternating current (AC) power grid 18 or a direct current (DC) power grid 18. The generator 14 is connected to the power grid 18 via a generator voltage regulator 20, which in some embodiments may also include a voltage convertor, such as an active rectifier, to convert the voltage output from the generator 14. The system 10 includes one or more propulsion motors 22 connected to the power grid 18, which are driven by electrical power generated by the generator 14. The propulsion motors 22 are each connected to a propulsor, for example a fan 24 to provide a propulsive force for the aircraft. In the illustrated embodiment three propulsion motor 22/fan 24 combinations are included, but one skilled in the art will readily appreciate that other quantities of motor 22/fan 24 combinations, such as two, four, or more combinations, may be utilized. Operation of the propulsion motors 22 may be managed by a motor control 26 operably connected to the power grid 18 and the respective propulsion motor 22.
In addition to the propulsion motors 22, other aircraft systems 28 may be connected to the power grid 18, such as cabin environmental control systems, lighting, and other systems. A system voltage controller 30 may be used to control voltage input to the aircraft systems 28. Additionally, in some embodiments, an energy storage system, such as one or more batteries 32 and a battery voltage regulator 34 are also connected to the power grid 18 to store excess power generated by the generator 14, and distribute electrical power from the one or more batteries 32 to the power grid 18 and the motors 22 and/or additional aircraft systems 28. Each of the generator 14, the batteries 32, the aircraft systems 28, and the propulsion motors 22 are switchably connectible and disconnectible from the power grid 18 via a plurality of switches 36, which may be operated by a system controller 38.
Referring now to
To prevent such consequences, the generator voltage regulator 20 includes sensors 40 to monitor the voltage and current incoming from the generator 14 for sudden or abrupt changes outside of an expected or preselected voltage band and current band, which may be expected during normal operation. Voltage and/or current outside of the preselected voltage band and/or the expected current band is indicative of a fault condition such as the sudden disconnection of the generator 14 and the generator voltage regulator 20 from the power grid 18. The generator voltage regulator 20 may use fault detection logic 42 to compare the voltage and current detected by sensors 40 to the preselected voltage band and current band. The detection of the fault triggers a shunt circuit, shown schematically at 44 to connect an emergency load 46 to the gas turbine engine 12. Additionally the fault detection logic 42 may be connected to the system controller 38 to slow the engine 14 as the emergency load 46 is removed and normal operation of the system 10 is restarted.
The hybrid propulsion system 10 may additionally include storage device 32 coupled to the power grid 18 and configured to power the motors 22 and subsequently the fans 24, in the event of an open circuit between the generator 14 and the power grid 18. As such, the hybrid propulsion system 10 may continue to power the aircraft, to enable safe operation in the event of a generator disconnect.
A method of operating the hybrid propulsion system 10 is illustrated in
Use of the fault detection logic 42 and the shunt circuit 46 provides a more consistent load on the engine 12 in the case of a fault in the generator 14 to aid in resisting engine 12 overspeed and provides a path for the excess energy when the generator 14 is disconnected from the power grid 18. Further, use of the shunt circuit 46 provides time for the system 10 to respond and recover from the rapid disconnect.
Another embodiment is illustrated in
Another method of operating the hybrid propulsion system 10 is illustrated in
Use of the variable resistive load path 50 aids in management of the power grid 18 and allows for a controlled decrease in load on the generator 14 to prevent generator 14 overvoltage and/or engine 12 overspeed conditions.
The term “about” is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” can include a range of ±8% or 5%, or 2% of a given value.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.
While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.
