The use of variable frequency drives for pumpset motors offers significant advantages for ship steering applications.   With a VFD motor pumpset, the steering can be ramped up to speed over the first and last 5 degrees of rotation to allow precise rudder positioning with no hydraulic shock.

VFD motor drives have the following advantages over constant running directional or servo valve pumpsets:

1.            Major reduction in electrical demand since the motor and pump only turn when a rudder angle change is underway.

2.            Major reduction in heat generation and consequent heat dissipation requirements due to the l...