# US 2022/0034262 A1 · Hybrid gas turbine engine system powered warm-up > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0034262 A1 - Document ID: US20220034262A1 - Status: Published application - Kind: A1 - Application number: 17/501,051 - Filed: 2021-10-14 - Published: 2022-02-03 - Earliest claimed: 2018-08-17 - Assignees: Raytheon Technologies Corporation - Applicants: Raytheon Technologies Corporation - Inventors: Neil Terwilliger; John P. Virtue - Web page: https://patentgrep.com/patent/US20220034262A1 ## CPC - F02K 5/00: Plants including an engine, other than a gas turbine, driving a compressor or a ducted fan - B64D 27/10: of gas-turbine type (jet aircraft B64D27/16) - B64D 33/00: Arrangement in aircraft of power plant parts or auxiliaries not otherwise provided for - F02C 6/14: Gas-turbine plants having means for storing energy, e.g. for meeting peak loads - F02C 7/268: Starting drives for the rotor {, acting directly on the rotor of the gas turbine to be started} - F02C 9/26: Control of fuel supply (F02C9/48 takes precedence; fuel valves F02C7/232) - F02C 9/54: by throttling the working fluid, by adjusting vanes - B64D 27/026: {comprising different types of power plants, e.g. combination of a piston engine and a gas-turbine (Hybrid electric aircraft B64D27/33)} - B64D 27/33: Hybrid electric aircraft - F05D 2260/85: Starting - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract An aspect includes a hybrid gas turbine engine system of a hybrid electric aircraft. The hybrid gas turbine engine system includes a gas turbine engine having a low speed spool and a high speed spool, a generator operably coupled to the low speed spool, a high spool electric motor operably coupled to the high speed spool, and a controller. The controller is configured to control the hybrid gas turbine engine system in a powered warm-up state to add heat to one or more components of the gas turbine engine by operating the gas turbine engine with a higher engine power setting above idle to drive rotation of the generator, transfer power from the generator to the high spool electric motor, and produce thrust. The gas turbine engine transitions from the powered warm-up state after reaching a target temperature of the one or more components in the powered warm-up state. ## Claims ### Claim 1 A hybrid gas turbine engine system of a hybrid electric aircraft, the hybrid gas turbine engine system comprising: a gas turbine engine comprising a low speed spool and a high speed spool; a generator operably coupled to the low speed spool of the gas turbine engine; a high spool electric motor operably coupled to the high speed spool; and a controller configured to: monitor for a powered warm-up request; initiate a powered warm-up state of the gas turbine engine based on detecting the powered warm-up request; control the hybrid gas turbine engine system in the powered warm-up state to add heat to one or more components of the gas turbine engine by operating the gas turbine engine with a higher engine power setting above idle to drive rotation of the generator, transfer power from the generator to the high spool electric motor, and produce thrust; and transition the gas turbine engine from the powered warm-up state after reaching a target temperature of the one or more components in the powered warm-up state. ### Claim 2 (depends on 1) The hybrid gas turbine engine system of claim 1, comprising one or more electric heaters, wherein the controller is configured to power the one or more electric heaters in the powered warm-up state. ### Claim 3 (depends on 1) The hybrid gas turbine engine system of claim 1, wherein the high speed spool is motored in reverse to urge heat in a reverse flow direction in the powered warm-up state. ### Claim 4 (depends on 1) The hybrid gas turbine engine system of claim 1, wherein the generator is a motor-generator operable in a generator mode to charge a battery system. ### Claim 5 (depends on 4) The hybrid gas turbine engine system of claim 4, wherein the motor-generator is operable in a motor mode to provide supplemental rotation force to the gas turbine engine. ### Claim 6 (depends on 1) The hybrid gas turbine engine system of claim 1, wherein the generator provides power for motoring the high speed spool. ### Claim 7 (depends on 1) The hybrid gas turbine engine system of claim 1, wherein the controller is configured to adjust one or more vane positions to reduce a compressor efficiency of the gas turbine engine and increase temperature at or below idle thrust in the powered warm-up state. ### Claim 8 (depends on 7) The hybrid gas turbine engine system of claim 7, wherein the controller is configured to adjust a power setting of the gas turbine engine to reduce the compressor efficiency of the gas turbine engine and increase temperature at or below idle thrust in the powered warm-up state. ### Claim 9 A propulsion system for a hybrid electric aircraft, the propulsion system comprising: a gas turbine engine comprising a low speed spool, a high speed spool, and a combustor; a generator operably coupled to the low speed spool of the gas turbine engine; an electric motor operably coupled to the high speed spool; and a controller configured to: control the gas turbine engine in a powered warm-up state to add heat to one or more components of the gas turbine engine by operating the gas turbine engine with a higher engine power setting above idle to drive rotation of the generator, transfer power from the generator to the electric motor, and produce thrust; and transition the gas turbine engine from the powered warm-up state after reaching a target temperature of the one or more components in the powered warm-up state. ### Claim 10 (depends on 9) The propulsion system of claim 9, wherein the powered warm-up state comprises powering one or more electric heaters. ### Claim 11 (depends on 9) The propulsion system of claim 9, wherein the high speed spool is motored in reverse to urge heat in a reverse flow direction in the powered warm-up state. ### Claim 12 (depends on 9) The propulsion system of claim 9, wherein the generator is a motor-generator operable in a generator mode to charge a battery system and/or provide power for motoring the high speed spool, and the generator is operable in a motor mode to provide supplemental rotation force to the gas turbine engine. ### Claim 13 (depends on 9) The propulsion system of claim 9, wherein a combination of vane positions and power setting of the gas turbine engine reduces a compressor efficiency of the gas turbine engine to increase temperature at or below idle thrust in the powered warm-up state. ### Claim 14 A method of providing a powered warm-up for a gas turbine engine of a hybrid electric aircraft, the method comprising: monitoring for a powered warm-up request; initiating a powered warm-up state of the gas turbine engine based on detecting the powered warm-up request, wherein the gas turbine engine comprises a low speed spool and a high speed spool; controlling the gas turbine engine in the powered warm-up state to add heat to one or more components of the gas turbine engine by operating the gas turbine engine with a higher engine power setting above idle to drive rotation of a generator operably coupled to the low speed spool of the gas turbine engine, transfer power from the generator to a high spool electric motor operably coupled to the high speed spool, and produce idle thrust; and transitioning the gas turbine engine from the powered warm-up state after reaching a target temperature of the one or more components in the powered warm-up state. ### Claim 15 (depends on 14) The method of claim 14, wherein the powered warm-up state comprises powering one or more electric heaters. ### Claim 16 (depends on 14) The method of claim 14, wherein the gas turbine engine comprises a low speed spool and a high speed spool, and further comprising: motoring the high speed spool in reverse to urge heat in a reverse flow direction in the powered warm-up state. ### Claim 17 (depends on 14) The method of claim 14, wherein the generator is a motor-generator operable in a generator mode to charge a battery system. ### Claim 18 (depends on 17) The method of claim 17, wherein the motor-generator is operable in a motor mode to provide supplemental rotation force to the gas turbine engine. ### Claim 19 (depends on 14) The method of claim 14, further comprising: adjusting one or more vane positions to reduce a compressor efficiency of the gas turbine engine and increase temperature at or below idle thrust in the powered warm-up state. ### Claim 20 (depends on 19) The method of claim 19, further comprising: adjusting a power setting of the gas turbine engine to reduce the compressor efficiency of the gas turbine engine and increase temperature at or below idle thrust in the powered warm-up state.