# US 10,483,765 B2 · Power generation and distribution system for offshore drilling units > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,483,765 B2 - Document ID: US10483765B2 - Status: Granted - Kind: B2 - Application number: 15/552,276 - Filed: 2016-02-22 - Published: 2018-02-01 - Granted: 2019-11-19 - Earliest claimed: 2015-02-20 - Assignees: Maersk Drilling A/S - Applicants: Maersk Drilling A/S - Inventors: John Røn Pedersen - Web page: https://patentgrep.com/patent/US10483765B2 ## CPC - E21B 41/00: Equipment or details not covered by groups E21B15/00 - E21B40/00 - H01F 27/24: Magnetic cores - H01F 27/28: Coils; Windings; Conductive connections - H02J 3/30: using dynamo-electric machines coupled to flywheels - H02J 3/32: using batteries or super capacitors with converting means - 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 - H02J 4/00: Circuit arrangements for mains or distribution networks not specified as AC or DC; Circuit arrangements for mains or distribution networks combining AC and DC sections or sub-networks (arrangements using intermediate DC-AC-DC conversion H02J1/002; arrangements using high-voltage DC [HVDC] links H02J3/36) - H02J 4/25: for transfer of electric power between AC and DC networks, e.g. for supplying the DC section within a load from an AC mains system - H02P 9/02: Details {of the control} - E21B 19/008: {Winding units, specially adapted for drilling operations} - H02J 3/14: by switching loads on to, or off from, the networks, e.g. progressively balanced loading - H02J 2105/12: supplying households or buildings - H02J 2105/31: {for ships or vessels} - H02P 27/06: using DC to AC converters or inverters (H02P27/05 takes precedence) - Y02B 70/3225: Demand response systems, e.g. load shedding, peak shaving - Y02E 60/16: Mechanical energy storage, e.g. flywheels or pressurised fluids - Y04S 20/222: Demand response systems, e.g. load shedding, peak shaving - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - 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 - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y04S: SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS ## Abstract A power generation and distribution system for a drilling rig includes (1) an AC bus and a DC bus, (2) an AC generator electrically connected to the AC bus, (3) an AC bus load electrically connected to the AC bus, (4) a first power transformer configured to convert a plurality of voltage phases of the AC bus into a plurality of corresponding secondary side voltage phases, (5) a first unidirectional AC-DC power converter connected between the secondary side voltage phases of the first power transformer and the DC bus, (6) one or more DC bus loads connected to the DC bus, and (7) a second AC-DC power converter connected between the DC bus and at least one of an auxiliary transformer winding of the first power transformer and a second power transformer for supplying power from the DC bus to the AC bus. ## Claims ### Claim 1 A power generation and distribution system for a drilling rig comprising: an AC bus and a DC bus, an AC generator electrically connected to the AC bus, an AC bus load electrically connected to the AC bus, a first power transformer configured to convert a plurality of voltage phases of the AC bus into a plurality of corresponding secondary side voltage phases, a first unidirectional AC-DC power converter connected between the secondary side voltage phases of the first power transformer and the DC bus for supplying power to the DC bus, one or more DC bus loads connected to the DC bus, and a second AC-DC power converter connected between the DC bus and at least one of an auxiliary transformer winding of the first power transformer and a second power transformer for supplying power from the DC bus to the AC bus. ### Claim 2 (depends on 1) The power generation and distribution system according to claim 1, wherein the first power transformer comprises: a plurality of primary side transformer windings and a plurality of secondary side transformer windings wound around a common magnetic core wherein the auxiliary transformer winding is wound around the common magnetic core to energize the plurality of primary side transformer windings. ### Claim 3 (depends on 1) The power generation and distribution system according to claim 1, further comprising a power management controller configured to: detect one or more parameters of the AC bus, selectively activate and deactivate each of the first AC-DC power converter and the second AC-DC power converter based on the one or more detected parameters of the AC bus. ### Claim 4 (depends on 3) The power generation and distribution system according to claim 3, wherein the power management controller is configured to: compare an AC voltage on the AC bus to at least one AC bus voltage threshold and based on said comparison: deactivate the first AC-DC power converter; and activate the second AC-DC power converter to energize at least one of the auxiliary transformer winding and the second power transformer from the DC bus. ### Claim 5 (depends on 1) The power generation and distribution system according to claim 1, wherein the second AC-DC power converter is a unidirectional power converter configured for transmission of energy from the DC bus to at least one of the auxiliary transformer winding and the second power transformer. ### Claim 6 (depends on 1) The power generation and distribution system according to claim 1, further comprising: a first energy storage connected to the DC bus to selectively supply power to the DC bus and absorb power from the first DC bus in accordance with a control signal. ### Claim 7 (depends on 6) The power generation and distribution system according to claim 6, wherein the first energy storage comprises one or more energy storage devices selected from a group of {a rechargeable battery, a capacitor, a flywheel}. ### Claim 8 (depends on 7) The power generation and distribution system according to claim 7, comprising a flywheel energy storage device possessing an energy storage capacity of more than 360 MJ. ### Claim 9 (depends on 6) The power generation and distribution system according to claim 6, wherein the first energy storage is arranged to carry out peak-shaving of the DC bus by at least temporarily supplying power to respective peak power demands of the one or more DC bus loads. ### Claim 10 (depends on 1) The power generation and distribution system according to claim 1, wherein the one or more DC bus loads comprises at least one of: a lifting device with a lifting capacity larger than 500 tons for a drill floor, a mud pump motor, a cement pump motor, a rotary table motor. ### Claim 11 (depends on 1) The power generation and distribution system according to claim 1, wherein the AC bus load comprises a thruster driver electrically connected to the AC bus. ### Claim 12 (depends on 1) The power generation and distribution system according to claim 1, wherein the AC bus comprises a plurality of AC bus subsections, wherein each AC bus subsection comprises first and second bus tie breakers for selectively connecting and disconnecting the AC bus subsection to the AC bus; and the DC bus comprises a plurality of DC bus subsections, wherein each DC bus subsection comprises first and second bus tie breakers for selectively connecting and disconnecting the DC bus subsection to the DC bus. ### Claim 13 (depends on 12) The power generation and distribution system according to claim 12, wherein the plurality of AC bus subsections are electrically connected to the AC bus in a ring configuration; and/or the plurality of DC bus subsections are electrically connected to the DC bus in a ring configuration. ### Claim 14 The power generation and distribution system according to any of the preceding claims, wherein each of the AC generator, the AC bus load and the first power transformer are directly connected to the AC bus without any intervening AC or DC bus planes or AC or DC bus lines. ### Claim 15 (depends on 1) The power generation and distribution system according to claim 1, wherein each of the first unidirectional AC-DC power converter and the one or more DC bus loads are directly connected to the DC bus without any intervening AC or DC bus planes or structures. ### Claim 16 A method of generating and distributing power on a drilling rig comprising: connecting an AC generator to an AC bus and running the AC generator to energize the AC bus with an AC voltage, loading the AC bus by connecting one or more AC loads to the AC bus, monitoring and detecting one or more parameters of the AC bus, comparing the one or more parameters of the AC bus to a bus voltage criterion, and if the one or more parameters of the AC bus do not match the bus voltage criterion, then activating a first unidirectional energy supply path from the AC bus to a DC bus to energize the DC bus and deactivating a second energy supply path from the DC bus to the AC bus; or if the one or more parameters of the AC bus match the bus voltage criterion, then deactivating the first energy supply path and activating the second energy supply path from the DC bus to the AC bus to energize the AC bus. ### Claim 17 (depends on 16) The method of generating and distributing power on a drilling rig according to claim 16, wherein the first energy supply path comprises: a first multi-phase power transformer configured to convert a plurality of voltage phases of the AC bus into a corresponding plurality of secondary side voltage phases and a first AC-DC power converter configured to convert the plurality of secondary side voltage phases to a DC voltage; and the second energy supply path comprises: a second AC-DC power converter connected between the DC bus and at least one of an auxiliary transformer winding of the first power transformer and a second power transformer, wherein a secondary side of the second power transformer is connected to the AC bus. ### Claim 18 (depends on 16) The method of generating and distributing power on a drilling rig according to claim 16, further comprising: connecting one or more DC bus loads to the DC bus, connecting a flywheel energy storage device to the DC bus, and controlling the flywheel energy storage device to selectively supply stored energy to the DC bus and absorb energy from the DC bus. ### Claim 19 (depends on 18) The method of generating and distributing power on a drilling rig according to claim 18, wherein the flywheel energy storage device is arranged to carry out peak-shaving of the DC bus by at least temporarily supplying power to respective peak power demands of the one or more DC bus loads. ### Claim 20 (depends on 16) The method of generating and distributing power on a drilling rig according to claim 16, further comprising supplying energy from a flywheel energy storage device to the AC bus through the second energy supply path.