What's the Meaning of Fast Phase Back?

Select "Read the whole paper" and study the top of page 1, which explains.

when I click it ,there is a message "could not open the file;file not found"..If u can upload the whole paper ?

How were you able to provide the link to it? Or do you not have Adobe Reader on your computer?

Sorry I misunderstood your words...

The PDF file I have read ,but it not explains clearly,in the end of the file ,there is a link to the whole paper which may explains it well,but i could not open the link..

It looks like I can paste in that part directly. Please see if the following helps:

1. Introduction

A system has been developed in conjunction with the thruster drive supplier to phase back the thruster drive current in 300 to 500 milliseconds by sensing the system frequency. This customized modification is referred to as a frequency dependent power phase back, and commonly referred to as frequency spillover, (FSO).

For a sudden loss of an on-line engine, this software solution can reduce system load fast enough to avoid blackout. This "buys time" to start and synchronize the next standby generator set. Initially thruster power is reduced below the DP command, but when additional generation is added (normal time is 20 to 35 seconds) the desired vessel position can be regained.

Most of the existing DP drilling vessels today do not have features in their power management system for the fast (in less than 1.5 seconds) reductions of load to prevent system blackouts. To compensate additional engines must be on-line for the unexpected loss of an engine/generator set. Of course the additional on-line engine, decreases the engine utilization rate.

The installation of a frequency sensitive, thruster fast phase-back system was installed and tested on the three "Enterprise Class" dynamically positioned drillships. Results of these installations produced very dramatic results; i.e., improved engine utilization, reduced total engine hours, reduced overall fuel usage, and provided some reductions in engine emissions.

Yes,I see..that's it.

Thanks a ton!