Background
Under international laws, the territorial waters around China operate under the Chinese Mare Clausum or 'Closed Sea' dictate, which means that the waters are not accessible to other states. Because of this, there is an increasing demand for Marine Surveillance vessels. The main function of a surveillance vessel, in accordance with the relevant laws and regulations, is to implement cruise surveillance in the waters under national jurisdiction (including coastal zones). The load on these vessels is variable and therefore the power system is critical in achieving the vessel's mode of operation.
Why AvK was chosen
- Chinese Surveillance Vessel Generator Room
China Marine Surveillance (CMS) and the power system design engineer specified four key requirements:-
- Twin propeller vessel requiring Power Take Off (PTO)/ Power Take In (PTI)/ Power Take Home (PTH) mode of operation
- Size ' physical space for alternator is limited
- Reliability - simple system is required
- Easy to maintain
AvK had a unique solution for PTH known as 'excitation controlled start'. This is a simple, smart alternator-motor start solution. This solution negates the need for any additional auxiliary components or a complex control system. The China Applications Engineering team worked in collaboration with CMS and the power system design engineer to provide a cost effective solution.
Vessel Mode of Operation
The vessel is operated in three modes of operation - cruise, full speed and emergency.
Cruise Mode of Operation: In this mode the surveillance vessel runs at low, stable speed. During this mode of operation the power system runs in eco mode with one AvK DSG 114K1/4 working in PTO and the other in PTI mode.
Full Speed Mode of Operation:†In this mode the surveillance vessel runs at high speed (>20 Knots) and therefore maximum output power is required.
Emergency Mode of Operation:†In emergency situations, where one side of the main engines fails (eg. ME3 & ME4), one of the AvK DSG 114K1/4(SG1) operates in PTO mode and the other (SG2) in PTH mode (self-start and driven by the propeller). This enables the vessel to return to port.
Summary
Having the opportunity to hold successful, open communication sessions with the ship owner, ship yard, power system design engineers and suppliers of other components was key in providing a reliable, effective solution. Communication with the ship owner to understand the vessels modes of operation enabled us to easily understand the requirements and effectively communicate the advantages of the AvK product with the power system design engineers. Working with the suppliers of other components also helped to interpret the system designer's requirements in order to deliver the solution. Having a global support network from internal teams such as Applications and Product Engineering also provided a forum to discuss and share previous experience of similar applications.