Hot standby power supply for a variable frequency drive

Patent metadata

Field	Value
Publication number	US-9325272-B2
Application number	US-201414153030-A
Country	US
Kind code	B2
Filing date	Jan 11, 2014
Priority date	Jan 11, 2013
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

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.

First claim

The invention claimed is:

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,
wherein the control unit is further configured to:
terminate the provision 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; and
restart the provision of electric power from the electric 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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

7. 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.

8. The hot standby power supply of claim 1 , 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.

9. 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, and
wherein the control unit is further configured to:
terminate the provision 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; and
restart the provision of electric power from the power storage unit to the converter power input of the variable frequency drive upon recei

Assignees

• Haugen Joern Tore
• Ohma Haavar Forsell
• Siemens Ag

Inventors

• Haugen Joern Tore
• Ohma Haavar Forsell

Classifications

• Y02B70/16

  Cross-Sectional Technologies · mapped topic

• H02J4/00 Primary

  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) · CPC title

• H02J9/04

  in which the distribution system is disconnected from the normal source and connected to a standby source · CPC title

• H02M2001/0032

  Electricity · mapped topic

• H02P27/04 Primary

  using variable-frequency supply voltage, e.g. inverter or converter supply voltage · CPC title