Equipment deployed in extreme environments such as the seafloor must be designed for very high reliability and resilience and able to operate within a temperature range of -25C to 80C without derating, only using conduction cooling. 

 

Subsea electronic equipment is often contained within a very tight tubular container fixed to the cable. 

 

Powerbox, one of Europe's largest power supply companies, has launched PRBX VB410-380, designed to guarantee the maximum level of isolation between the high-voltage input and the low-voltage output, but with enough physical isolation between the different components to allow for tight integration.

 

While the technology has thus far been sold to two European oilers, the company does have an Australian office in Sydney to deal with local opportunities.

 

The Norwegians have already started putting compression on the seabed, though that method is still largely untested on a global basis, including in Australia.

 

Woodside Petroleum technology development manager - upstream, Nino Fogliani outlined the results of the oiler's subsea gas processing investigations at AOG's Subsea Forum this year, including cooling, separation, chemical injection and compression/pumping, to condition wellstream fluids for long distance subsea transportation.

 

Woodside chief operations officer Mike Utsler recently told Energy News that about a quarter of the world's hydrocarbon production was expected to come from subsea fields by 2030.

 

The situation is no different locally where there is believed to be an extra 30 trillion cubic feet of potentially recoverable gas in the North West Shelf.

 

In fact, advancements in subsea technology and the ability to tie back fields further offshore contributed to Woodside deciding to expand its Pluto LNG operation.

 

Industrial applications such as gas and oil situated on the seafloor, or long distance transmission cables, require very specific power solutions to supply a subset of electronic equipment operating 24/7 with no downtime, and where maintenance is either very expensive or simply not an option. 

 

These applications are usually powered from the shore or from a technical platform generator via a high voltage line, which depending on the power station could be AC or DC voltage within the range of 300 to 900 volts AC, or 400-1500VDC, ultimately requiring a 48VDC intermediate bus voltage to power electronic equipment.  

 

Powerbox says outputs need to be able to operate in parallel in order to increase the power or to offer redundancy.

 

"Delivering power to extreme applications such as subsea ones is always a challenge for designers," Powerbox spokesman Patrick Le Fevre said. 

 

"But in developing standardised, easily reusable sub-systems such as the VB410-380 we have shortened the design cycle and time-to-market for our customers."

 

The secondary stage of the PRBX VB380 includes four independent output modules each delivering 95W. 

 

Each output has its own current limiting capability and an integrated digital controller to monitor voltage and current that is readable through a CAN-Bus (controller area network), which is basically a vehicle bus standard-designed to allow microcontrollers and devices to communicate with each other in applications without a host computer.

 

Each output can be on/off controlled or made redundant. 

 

The CAN-Bus is also used for diagnostic and predictive actions, for example for shutdown modules when not required to maintain peak power.