Scope of work
The DP2 construction support vessel, Boka Northern Ocean, implemented a hybrid upgrade with the installation of a battery energy storage system (BESS) to provide blackout prevention support, peak shaving, dynamic load support to diesel generators and optimisation of vessel power generation system loading. The BESS can be utilised in all modes of operation but most notably during DP operations where GM completed a FMEA study to verify the failure modes and effects and supplemented these with a set of proving trials to verify the desktop analysis.
Challenges
Whilst the vessel operates with the AC power distribution switchboards open bus (split in to two sections by means of bustie circuit breakers), the convertors associated with the BESS and the DC link connected to the batteries create a connection between Port and Starboard AC distribution systems. This connection had to be suitably evaluated and tested to verify that failure effects could not propagate between Port and Starboard, or if they could, that the system was suitably protected against these failure modes such that the vessel’s Worst Case Failure Design Intent for DP operations was not exceeded.
Outcome – Results and Deliverables
GM delivered a new DP FMEA and associated set of proving trials for the vessel incorporating the battery hybrid upgrade. In addition, GM also delivered a FMEA for the vessel as required for the BV Class notation Battery(power). GM witnessed the trials which successfully demonstrated the system performance and verified that no single failure effect would exceed the vessel’s Worst Case Failure Design Intent. All reports were approved by the Classification Society and accepted by Boskalis in line with the project timescales and the vessel is now operating with the BESS system active.
