Classified as a dynamic positioning class 3 (DP3) deep sea vessel (DSV), Deep Explorer II is designed and “and certified for subsea projects in the demanding North Sea/Canada market.” Equipped with the latest innovative features and technology, the vessel is considered to be among the most “modern and versatile DSV in the world.”
Although built and engineered using the smartest technology and solutions available, the Deep Explorer II was built with many different suppliers having delivered their individual scope of work—with none having considered their contribution to the THD (total harmonic distortion) pollution on the vessel’s grid.
Consequently, despite its new construction, the vessel was notified by DNV GL* that it did not comply with harmonic regulations. Furthermore, DNV GL warned that they could experience tripping issues if they did not consider a strong enough harmonic mitigation solution.
Needing to create a solution for a multilayer grid with a complex set-up including emergency generators, switches, and feeds from 230V-6.6kV, and although experiencing difficulty obtaining information regarding filters, chokes, manufacturers, and other relevant technical data to be able to size and plan a solution, Comsys was able to install DNV GL compliant harmonic compensation to keep Deep Explorer II in operation.
Products used in this installation:
ADF Power Tuning was selected as the harmonic compensation solution for Deep Explorer II due to its scalability, flexible set-up, and that it would be easy to retrofit in the future. Also, more importantly to Vard, ADF technology was selected because it has been used successfully by the customer and proved reliable aboard other ships in their fleet.
After installation, Vard successfully met the DNV GL harmonic requirements. And with the filters able to be mounted in-parallel to the load and on the bus bar, Vard experienced the installation flexibility they needed. Additionally, due to the simplicity of the Sensorless Control option, installation was significantly smoother and more streamlined, especially given the limited availability of space aboard the vessel.
Thanks to the responsiveness and flexibility of Comsys, we solved this precarious situation within the time frame of three months successfully.
– Frank Raknes, Project Manager
*DNV GL is an international certification body and classification society with expertise in technical assessment, advisory, and risk management.