Partitioned motor drive apparatus for subsea applications

Patent metadata

Field	Value
Publication number	US-2016181964-A1
Application number	US-201414575032-A
Country	US
Kind code	A1
Filing date	Dec 18, 2014
Priority date	Dec 18, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

A system includes an above-surface control unit and a subsea motor drive unit. The above-surface control unit includes a variable speed motor control circuit configured to generate at least one switch control signal and a first communications circuit configured to transmit the at least one switch control signal over a communications medium. The subsea motor drive unit includes a driver circuit configured to be coupled to an electric motor and comprising at least one semiconductor switch and a second communications circuit coupled to the first communications circuit via the communications medium and configured to recover the transmitted at least one switch control signal and to apply the recovered at least one switch control signal to the driver circuit.

First claim

That which is claimed:

1 . A system comprising:
an above-surface control unit comprising:
a variable speed motor control circuit configured to generate at least one switch control signal; and
a first communications circuit configured to transmit the at least one switch control signal over a communications medium; and
a subsea motor drive unit comprising:
a driver circuit configured to be coupled to an electric motor and comprising at least one semiconductor switch; and
a second communications circuit coupled to the first communications circuit via the communications medium and configured to recover the transmitted at least one switch control signal and to apply the recovered at least one switch control signal to the driver circuit.

2 . The system of claim 1 , wherein the first and second communications circuits are serial communications circuits.

3 . The system of claim 2 , wherein the first communications circuit is configured to multiplex a plurality of switch control signals and wherein the second communications circuit is configured to demultiplex the multiplexed plurality of switch control signals.

4 . The system of claim 3 , wherein the motor control circuit is configured to operate the driver circuit as an inverter.

5 . The system of claim 1 , wherein the second communications circuit is configured to transmit at least one sensor signal over the communications medium, wherein the first communications circuit is configured to receive the transmitted at least one sensor signal and wherein the variable speed motor control circuit is configured to generate the at least one switch control signal responsive to the received at least one sensor signal.

6 . The system of claim 1 , wherein the subsea motor drive unit and the above-surface control unit are configured to receive electric power from a separate power sources.

7 . The system of claim 1 , wherein the communications medium comprises a fiber optic cable.

8 . The system of claim 7 , wherein the fiber optic cable has a length greater than about 1 kilometer.

9 . The system of claim 1 , wherein the variable speed motor control circuit comprises a first variable speed motor control circuit and wherein the system further comprises a subsea second variable speed motor control circuit configured to provide at least one switch control signal to the driver circuit.

10 . An apparatus comprising:
a submersible driver circuit configured to be coupled to an electric motor and comprising at least one semiconductor switch; and a submersible communications circuit coupled to the submersible driver circuit and configured to be coupled to an control unit via a communications cable, to recover at least one switch control signal transmitted over the communications cable by the control unit and to apply the recovered at least one switch control signal to the submersible driver circuit.

11 . The apparatus of claim 10 , wherein the communications circuit is a serial communications circuit.

12 . The system of claim 10 , wherein the communications circuit is configured to transmit at least one sensor signal over the communications cable.

13 . The system of claim 10 , wherein the driver circuit is configured to receive electric power from a subsea power distribution system.

14 . The system of claim 10 , wherein the communications circuit is an optical communications circuit.

15 . The system of claim 10 , wherein the submersible communications circuit is configured to be coupled to an above-surface control unit via the communications cable

16 . A system comprising:
a submerged electric motor; and a variable speed motor drive comprising a submerged motor drive unit coupled to the electric motor and comprising an inverter circuit including at least one semiconductor switch and a above-surface control unit coupled to the submerged motor drive unit via a fiber optic communications cable, the above-surface control unit transmitting at least one switch control signal for the at least one semiconductor switch to the submerged motor drive unit via the fiber optic communications cable.

17 . The system of claim 16 , wherein the submerged motor drive unit transmits at least one sensor signal to the above-surface unit via the fiber optic communications cable, and wherein above-surface control unit generates the at least one switch control signal responsive to the received at least one sensor signal.

18 . The system of claim 16 , wherein the submerged motor drive unit receives power from a different power source than the above-surface unit.

19 . The system of claim 18 , wherein the submerged motor drive unit receives electric power from a subsea power system.

20 . The system of claim 16 , wherein the system further comprises a submerged variable speed motor control unit that controls the submerged motor drive unit.

Assignees

• Eaton Corp

Inventors

• Nojima Geraldo

Classifications

• H02P23/00

  Arrangements or methods for the control of AC motors characterised by a control method other than vector control · CPC title

• H02P31/00

  Arrangements for regulating or controlling electric motors not provided for in groups H02P1/00 - H02P5/00, H02P7/00 or H02P21/00 - H02P29/00 · CPC title

• F04D13/086 Primary

  the pump and drive motor are both submerged · CPC title

• F04D25/0686

  specially adapted for submerged use · CPC title

• H02P27/06 Primary

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title