Dc powered rov and umbilical

Abstract

A method of operating a remotely operated underwater vehicle (ROV) includes launching the ROV from a vessel into water; supplying a direct current (DC) power signal to the ROV from the vessel via an umbilical; and sending a first command signal to the ROV from the vessel via the umbilical while supplying the DC power signal.

1 . A method of operating a remotely operated underwater vehicle (ROV), comprising:
 launching the ROV from a vessel into water;   supplying a direct current (DC) power signal to the ROV from the vessel via an umbilical; and   sending a first command signal to the ROV from the vessel via the umbilical while supplying the DC power signal.   
     
     
         2 . The method of  claim 1 , wherein the umbilical comprises only two conductors. 
     
     
         3 . The method of  claim 1 , wherein:
 the ROV comprises a power converter, and   the method further comprises converting the DC power signal to a second power signal using the power converter.   
     
     
         4 . The method of  claim 3 , wherein:
 the ROV comprises an electric motor, and   the second power signal is supplied to the electric motor.   
     
     
         5 . The method of  claim 4 , wherein the second power signal is a three phase alternating current power signal. 
     
     
         6 . The method of  claim 4 , wherein the electric motor is an alternating current motor. 
     
     
         7 . The method of  claim 4 , wherein the electric motor is a DC motor. 
     
     
         8 . The method of  claim 4 , wherein the electric motor is a reluctance motor. 
     
     
         9 . The method of  claim 4 , wherein the electric motor is a permanent magnet motor. 
     
     
         10 . The method of  claim 3 , wherein the second power signal is a reduced voltage DC power signal. 
     
     
         11 . The method of  claim 1 ,
 further comprising sending a second command signal to a tether management system via the umbilical, thereby releasing the ROV and unwinding a tether,   wherein the ROV receives the DC power signal and the first command signal via the umbilical and the tether.   
     
     
         12 . The method of  claim 11 , wherein each of the umbilical and the tether comprises only two conductors. 
     
     
         13 . The method of  claim 1 , wherein the DC power signal is greater than or equal to one hundred volts. 
     
     
         14 . The method of  claim 1 , wherein:
 the ROV comprises a video camera, and   the method further comprises sending a video signal from the video camera to the vessel via the umbilical.   
     
     
         15 . A remotely operated underwater vehicle (ROV), comprising:
 a chassis;   a float connected to the chassis;   a thruster connected to the chassis, the thruster comprising an electric motor;   a manipulator connected to the chassis;   a video camera connected to the chassis;   a light connected to the chassis;   a diplexer connected to the chassis and operable to connect to a two conductor tether and split a composite signal from the tether into a DC power signal and a first command signal;   a power converter connected to the chassis and operable to receive the DC power signal from the diplexer and supply a second power signal to the thruster motor; and   a programmable logic controller connected to the chassis and operable to receive a first command signal from the diplexer, modulate a video signal from the camera, and transmit the video signal to the diplexer.   
     
     
         16 . The ROV of  claim 15 , wherein the second power signal is a three phase alternating current power signal. 
     
     
         17 . The ROV of  claim 15 , wherein the electric motor is an alternating current motor. 
     
     
         18 . The ROV of  claim 15 , wherein the electric motor is a DC motor. 
     
     
         19 . The ROV of  claim 15 , wherein the electric motor is a reluctance motor. 
     
     
         20 . The ROV of  claim 15 , wherein the electric motor is a permanent magnet motor. 
     
     
         21 . The ROV of  claim 15 , wherein the power converter is also operable to supply a reduced voltage DC power signal to the programmable logic controller. 
     
     
         22 . A system for deploying a remotely operated underwater vehicle (ROV), comprising:
 the ROV of  claim 15 ; and   a tether management system (TMS) operable to connect to the ROV and comprising:
 a winch operable to wind and unwind the tether and comprising an electric motor; 
 a diplexer operable to connect to a two conductor umbilical and split a composite signal from the umbilical into a DC power signal and a second command signal; and 
 a power converter operable to receive the DC power signal from the TMS diplexer and supply a second power signal to the winch motor.