WinGD X62DF-S2.0 - Electrically-Driven Compensator (External Compensator); Locating an Electrically-Driven Compensator

Marine Installation Manual 2022-03 6-4
6 Engine Dynamics
6.1 External mass forces and moments
X62DF-S2.0
For the use of only a single iELBA, the mode shapes of the vertical hull girder vi-
brations must be considered. If the mode shapes of the vertical hull girder vibra-
tions are unknown, the application of only a single iELBA may be ineffective.
The calculation of the vertical hull girder frequencies, the corresponding mode
shapes and consequently the decision on the number of iELBA systems to be in-
stalled is the responsibility of the shipyard.
Electrically-driven compensator (external compensator)
Alternatively, or if the ship’s vibration pattern is not known at an early stage, an
electrically-driven compensator can be installed or retrofitted if disturbing
second order vibrations should occur. As seen in Figure 6-3, such a compensator
is usually installed in the steering gear compartment. It is tuned to the engine op-
erating speed and controlled accordingly.
Figure 6-3 Locating an electrically-driven compensator
NOTE
The iELBA system cannot be retrofitted to the engine. The iELBA must
be ordered, designed and implemented on the engine prior to manufac-
turing.
SM-0031
F
2V
M
2V
= F
2V
× L
L
M
2V
Electrically-driven
2
nd
order
compensator