# US 2021/0344291 A1 · Hybrid synchronous condenser and power generation unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0344291 A1 - Document ID: US20210344291A1 - Status: Published application - Kind: A1 - Application number: 17/286,497 - Filed: 2018-10-24 - Published: 2021-11-04 - Earliest claimed: 2018-10-24 - Assignees: Siemens Energy, Inc. - Applicants: Siemens Energy, Inc. - Inventors: Peter Jon Clayton; Avinash Balbahadur - Web page: https://patentgrep.com/patent/US20210344291A1 ## CPC - H02J 3/1885: using rotating AC generators, e.g. synchronous generators - H02P 9/06: Control effected upon clutch or other mechanical power transmission means and dependent upon electric output value of the generator - F01D 15/10: Adaptations for driving, or combinations with, electric generators - F02C 7/268: Starting drives for the rotor {, acting directly on the rotor of the gas turbine to be started} - F02C 7/275: Mechanical drives - H02J 3/30: using dynamo-electric machines coupled to flywheels - H02J 3/38: Arrangements for feeding a single network from two or more generators or sources in parallel; Arrangements for feeding already energised networks from additional generators or sources in parallel - H02K 7/108: with friction clutches - H02K 7/116: with gears - H02K 7/1823: {structurally associated with turbines or similar engines} - H02P 9/105: {for increasing the stability} - F05D 2220/32: in gas turbines - F05D 2220/76: an electrical generator - F05D 2260/40: Transmission of power - F05D 2260/4023: through a friction clutch - F05D 2260/4031: as in toothed gearing - H02P 2101/25: for combustion engines - H02P 2103/20: of the synchronous type - Y02E 40/30: Reactive power compensation - Y02E 60/16: Mechanical energy storage, e.g. flywheels or pressurised fluids - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - 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) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A hybrid power generation unit and synchronous condenser system connectable to a power grid includes a combustion turbine coupled to a first shaft and operable to provide rotational energy to the first shaft, a gear box coupled to the first shaft, and a first clutch portion coupled to the first shaft. A motor is selectively coupled to the gear box to turn the gear box and the first shaft, a second clutch portion is connected to a second shaft, and a generator is coupled to the second shaft. The generator is selectively connectable to the grid to operate as a synchronous condenser when the first clutch portion and the second clutch portion are disengaged and to convert rotational energy from the first shaft to electrical power when the first clutch portion and the second clutch portion are engaged. ## Claims ### Claim 1 A hybrid power generation unit and synchronous condenser system connectable to a power grid, the system comprising: a combustion turbine coupled to a first shaft and operable to provide rotational energy to the first shaft; a gear box coupled to the first shaft; a first clutch portion coupled to the first shaft; a motor selectively coupled to the gear box to turn the gear box and the first shaft; a second clutch portion connected to a second shaft; and a generator coupled to the second shaft, the generator selectively connectable to the grid to operate as a synchronous condenser when the first clutch portion and the second clutch portion are disengaged and to convert rotational energy from the first shaft to electrical power when the first clutch portion and the second clutch portion are engaged. ### Claim 2 (depends on 1) The power generation unit of claim 1, wherein the first shaft and the second shaft are substantially colinear. ### Claim 3 (depends on 2) The power generation unit of claim 2, wherein the motor rotates along an axis that is not colinear with the first shaft. ### Claim 4 (depends on 1) The power generation unit of claim 1, further comprising a generator excitation system operable to vary an excitation voltage for the generator when operating as a synchronous condenser to vary the reactive power output of the generator. ### Claim 5 (depends on 1) The power generation unit of claim 1, further comprising a variable speed drive operable to accelerate the generator to synchronous speed. ### Claim 6 (depends on 1) The power generation unit of claim 1, wherein the motor is a variable speed motor. ### Claim 7 (depends on 1) The power generation unit of claim 1, wherein the motor is supported on a third shaft that is parallel to and spaced apart from the first shaft. ### Claim 8 (depends on 1) The power generation unit of claim 1, wherein the motor is operable to accelerate the combustion turbine to a firing speed. ### Claim 9 A method of operating a hybrid power generation unit and synchronous condenser, the method comprising: accelerating a generator to synchronize the generator with an electrical grid; varying an excitation voltage for the generator to vary the reactive power output of the generator; engaging a motor with a gear box to rotate the gear box; accelerating a combustion turbine to a firing speed in response to rotation of the gear box; firing the combustion turbine; accelerating the combustion turbine to the same speed as the generator; engaging a clutch between the combustion turbine and the generator such that the combustion turbine drives the generator; and outputting electrical power from the generator to the grid. ### Claim 10 (depends on 9) The method of claim 9, further comprising operating a variable frequency drive to accelerate the generator. ### Claim 11 (depends on 9) The method of claim 9, wherein the combustion turbine, the generator, and the clutch rotate on a common rotational axis. ### Claim 12 (depends on 9) The method of claim 9, further comprising a motor selectively operable to drive the combustion turbine. ### Claim 13 (depends on 12) The method of claim 12, wherein the combustion turbine rotates about a first axis and the motor rotates about a second axis separate from and parallel to the first axis. ### Claim 14 (depends on 12) The method of claim 12, wherein the accelerating the combustion turbine to the same speed as the generator step includes disengaging the motor from the gear box. ### Claim 15 A hybrid power generation unit and synchronous condenser system connectable to a power grid, the unit comprising: a first shaft; a combustion turbine coupled to the first shaft and operable to provide rotational energy to the first shaft; a second shaft colinear with the first shaft; a generator coupled to the second shaft and electrically connectable to the power grid; a third shaft spaced apart from the first shaft and the second shaft; a motor connected to the third shaft and driven by a variable speed drive; a gear box positioned to selectively couple the first shaft and the third shaft for rotation; and a clutch positioned to selectively connect the first shaft and the second shaft. ### Claim 16 (depends on 15) The power generation unit of claim 15, wherein the system is operable in a synchronous condenser mode in which the gear box is disengaged such that the first shaft and the third shaft are not connected, and the clutch is disengaged such that the first shaft and the second shaft are not connected. ### Claim 17 (depends on 16) The power generation unit of claim 16, wherein the turbine is in an idle state during operation in the synchronous condenser mode. ### Claim 18 (depends on 16) The power generation unit of claim 16, further comprising a generator exciter system operable to vary a field voltage of the generator to control the reactive power of the generator when in the synchronous condenser mode. ### Claim 19 (depends on 15) The power generation unit of claim 15, wherein the system is operable in a power generation mode in which the gear box is disengaged such that the first shaft and the third shaft are not connected, and the clutch is engaged such that the first shaft and the second shaft are connected and the generator is operable to convert rotational power produced by the turbine to electrical power to be directed to the power grid. ### Claim 20 (depends on 15) The power generation unit of claim 15, wherein the system is operable in a start-up mode in which the gearbox is engaged such that the first shaft and the third shaft are connected, and the clutch is disengaged such that the first shaft and the second shaft are not connected and the motor is operable to accelerate the turbine to a firing speed.