# US 2014/0197768 A1 · Hot Standby Power Supply for a Variable Frequency Drive > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197768 A1 - Document ID: US20140197768A1 - Status: Published application - Kind: A1 - Application number: 14/153,030 - Filed: 2014-01-11 - Published: 2014-07-17 - Earliest claimed: 2013-01-11 - Assignees: Siemens Aktiengesellschaft - Inventors: Joern Tore Haugen; Haavar Forsell Ohma - Web page: https://patentgrep.com/patent/US20140197768A1 ## CPC - H02P 27/04: using variable-frequency supply voltage, e.g. inverter or converter supply voltage - 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 7/34: Parallel operation in networks using both storage and other DC sources, e.g. providing buffering (H02J7/14 takes precedence) - H02J 9/04: in which the distribution system is disconnected from the normal source and connected to a standby source - H02M 1/0032: {Control circuits allowing low power mode operation, e.g. in standby mode} - Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes - Y02B 70/30: Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level - Y04S 20/20: End-user application control systems - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS - 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 hot standby power supply for a variable frequency drive of a floating vessel is provided. The variable frequency drive may power an electric motor of the floating vessel. The hot standby power supply includes a power input for receiving electric power from a main power supply of the floating vessel. The hot standby power supply also includes a first electric connection configured to supply electric power at a first voltage level to a converter power input of the variable frequency drive, and a second electric connection configured to supply electric power at a second voltage level to control power input of the variable frequency drive. The first voltage level is higher than the second voltage level. A transformer is further provided for transforming received electric power to the first voltage level or to the second voltage level. ## Claims ### Claim 1 A hot standby power supply for a variable frequency drive of a floating vessel, the variable frequency drive powering an electric motor of the floating vessel, the hot standby power supply comprising: a power input operable for receiving electric power from a main power supply of the floating vessel; a first electric connection configured to supply electric power at a first voltage level to a converter power input of the variable frequency drive; a second electric connection configured to supply electric power at a second voltage level to a control power input of the variable frequency drive, wherein the first voltage level is higher than the second voltage level; a transformer operable for transforming received electric power to the first voltage level or to the second voltage level; an electric power storage unit operable for storing and supplying electric power, the electric power storage unit being electrically connected so as to be operable to supply electric power to both the first electric connection and the second electric connection, the first electric connection or the second electric connection being supplied via the transformer for providing the first voltage level or the second voltage level, respectively; and a control unit configured to control the hot standby power supply such that in operation, electric power received at the power input is provided to the converter power input and to the control power input of the variable frequency drive via the first electric connection and the second electric connection, and that upon an interruption in the supply with electric power from the main power supply, electric power is supplied from the electric power storage unit to the converter power input and to the control power input of the variable frequency drive via the first electric connection and the second electric connection. ### Claim 2 (depends on 1) The hot standby power supply of claim 1, wherein the transformer is a step down transformer configured to provide a voltage conversion from the first voltage level to the second voltage level. ### Claim 3 (depends on 1) The hot standby power supply of claim 1, wherein the transformer is a first transformer, and wherein the hot standby power supply further comprises a second transformer connected to the power input of the hot standby power supply and configured to convert received electric power from a receiving voltage level to the first voltage level or the second voltage level, the electric power storage unit being electrically coupled to a secondary side of the second transformer. ### Claim 4 (depends on 1) The hot standby power supply of claim 1, further comprising a third electric connection to an auxiliaries power input of the variable frequency drive, the auxiliaries power input being electrically coupled to one or more auxiliaries of the variable frequency drive including at least a cooling unit, the hot standby power supply being configured to supply electric power at the first voltage level or the second voltage level to the auxiliaries power input so as to provide electric power to the cooling unit. ### Claim 5 (depends on 1) The hot standby power supply of claim 1, wherein the received electric power is AC electric power, the electric power storage unit comprising a DC electric power storage element and a converter, the converter being configured to convert received AC electric power to DC electric power when charging the storage element and to convert DC electric power supplied by the storage element to AC electric power when the electric power storage unit supplies electric power to the first electric connection and the second electric connection. ### Claim 6 (depends on 5) The hot standby power supply of claim 5, wherein the DC electric power storage element comprises a battery, a capacitor bank, or the battery and the capacitor bank. ### Claim 7 (depends on 1) The hot standby power supply of claim 1, further comprising a communication link towards a controller of the variable frequency drive configured to enable a communication between the control unit of the hot standby power supply and the controller of the variable frequency drive. ### Claim 8 (depends on 1) The hot standby power supply of claim 1, wherein the control unit is configured to terminate the supply of electric power from the electric power storage unit to at least the converter power input of the variable frequency drive after a first amount of time or after a predetermined condition is met. ### Claim 9 (depends on 8) The hot standby power supply of claim 8, wherein the control unit is configured to restart supplying electric power from the power storage unit to the converter power input of the variable frequency drive upon receiving an indication that the supply with electric power from the main power supply will resume. ### Claim 10 (depends on 9) The hot standby power supply of claim 9, wherein the control unit is configured to restart supplying electric power from the power storage unit to the converter power input of the variable frequency drive upon receiving an indication on a start signal being supplied to a generator of the main power supply. ### Claim 11 A drive system comprising: a variable frequency drive for powering an electric motor of a floating vessel, the variable frequency drive comprising: a converter having a DC link; a controller configured for controlling the variable frequency drive; a converter power input configured for supplying electric power to the converter to precharge the DC link; and a controller power input configured for supplying electric power to the controller of the variable frequency drive; and a hot standby power supply for the variable frequency drive, the hot standby power supply comprising: a power input operable for receiving electric power from a main power supply of the floating vessel; a first electric connection configured to supply electric power at a first voltage level to a converter power input of the variable frequency drive; a second electric connection configured to supply electric power at a second voltage level to a control power input of the variable frequency drive, wherein the first voltage level is higher than the second voltage level; a transformer operable for transforming received electric power to the first voltage level or to the second voltage level; an electric power storage unit operable for storing and supplying electric power, the electric power storage unit being electrically connected so as to be operable to supply electric power to both the first electric connection and the second electric connection, the first electric connection or the second electric connection being supplied via the transformer for providing the first voltage level or the second voltage level, respectively; and a control unit configured to control the hot standby power supply such that in operation, electric power received at the power input is provided to the converter power input and to the control power input of the variable frequency drive via the first electric connection and the second electric connection, and that upon an interruption in the supply with electric power from the main power supply, electric power is supplied from the electric power storage unit to the converter power input and to the control power input of the variable frequency drive via the first electric connection and the second electric connection, wherein the first electric connection is electrically connected to the converter power input, and the second electric connection is electrically connected to the controller power input. ### Claim 12 (depends on 11) The drive system of claim 11, wherein the electric motor is an electric motor of a thruster of the floating vessel. ### Claim 13 (depends on 11) The drive system of claim 11, wherein the drive system is a drive system of a dynamically positioned vessel, and the variable frequency drive is configured to supply electric power to an electric motor of a thruster of the dynamically positioned vessel. ### Claim 14 (depends on 11) The drive system of claim 11, wherein the variable frequency drive comprises a charging transformer connected between the converter power input and the converter. ### Claim 15 (depends on 11) The drive system of claim 11, wherein the variable frequency drive comprises a cooling unit, and the drive system comprises an electric connection between the hot standby power supply and the variable frequency drive enabling the supply of electric power from the electric power storage unit to the cooling unit. ### Claim 16 (depends on 11) The drive system of claim 11, further comprising: a variable frequency drive cabinet, the variable frequency drive being mounted in the variable frequency drive cabinet; and a hot standby power supply cabinet, the hot standby power supply being mounted in the hot standby power supply cabinet, the hot standby power supply cabinet being mounted on a common base frame with the variable frequency drive cabinet. ### Claim 17 A method for operating a hot standby power supply for supplying electric power to a variable frequency drive, the method comprising: receiving electric power at a power input of the hot standby power supply from a main power supply; providing electric power at a first voltage level to a converter power input of the variable frequency drive via a first electric connection; providing electric power at a second voltage level to a controller power input of the variable frequency drive via a second electric connection, wherein the first voltage level is higher than the second voltage level; transforming, with a transformer, received electric power to the first voltage level or to the second voltage level; providing received electric power to a power storage unit for charging the power storage unit; detecting an interruption in the supply with electric power by the main power supply; and supplying electric power from the power storage unit to the converter power input and to the controller power input of the variable frequency drive via the first electric connection and the second electric connection, the first electric connection and the second electric connection being supplied with the electric power via the transformer for providing the respective first voltage level or second voltage level.