Woodward EGCP‐3 LS and SPM‐D on the Yacht Sea Jewel Application

Application

The ship’s chief engineer required several modes of operation in order to

optimize the performance of the yacht’s electrical system.

During normal operation, the load on the ship can be supplied by one genset, but when seas are

rough and the ship’s stabilizers are running, there is a need for additional generation.

In this mode of operation, both gensets must run continuously.

Also, the ship needs to be connected to shore power when in port.

In order to eliminate a blackout on the ship during the power transfer,

and to reduce the amount of load generated to the shore power,

a scheme was developed to provide an automatic closed transition using a Woodward SPM‐D.

Using the sequencing functionality of the EGCP‐3. the control is configured to

start an additional unit two seconds after the load on the master unit exceeds 75%.

When the load reduces to below 30%, the slave unit is removed from the system after 60 seconds.

The controls needs to be able to trade master/slave relationships,

so a switch is used to place one control in Auto and Run w/ Load (Master)

and the second unit in Auto (Slave). Both controls have the option to operate in either

mode—so if sequencing needs to be avoided, the operator can place both

controls in Auto and Run w/ Load, and both units will share the entire electrical load.

The closed transition to shore power was solved by sending a remote fault input to the EGCP‐3 when the shore

power breaker is closed onto the system. When coming into port, ship’s power is reduced before synchronizing to

shore power. This means that only one unit is online with low load. When shore power is connected, the operator

adjusts a switch from “Generators” to “Shore” power. Instigating this switch turns on the SPM‐D and allows

the unit to begin sending digital signals to the EGCP‐3 LS to synchronize the ship’s power to shore power.

When the breaker is closed, the aux feedback is sent to a remote input on the EGCP‐3 that opens the

generator breaker and shuts the generator down. The system is then completely supplied by shore power.

When the ship switches back to Generators, the remote input is cleared and the unit coming online

synchronizes to the shore power, closes its breaker, and the shore power breaker is immediately opened.

The system is then on Generator power.