A guide to DP electrical power and control systems

 

Version history

November 2023 Rev. 2.1 – Document QA check, addition of document map / navigation pane, no change to content

October 2020 Rev. 2 – Review and update as part of the IMCA review programme including the merging of IMCA M 196 Guidance on The Design, Selection, Installation and Use of Uninterruptible Power Supplies On-board Vessels

September 2016 Rev. 1 – Review and update as part of the IMCA review programme.

 

Summary

This handbook is intended to provide a reference guide for those involved in designing, assessing, and maintaining dynamically positioned (DP) vessels.

The original version of document consolidated and updated three DPVOA/IMCA guidance documents:

• 126 DPVOA – Reliability of electrical systems on DP vessels
• 108 DPVOA – Power system protection for DP vessels
• IMCA M154 – Power management system study.

These documents were closely related and published between 1992 and 2000. Since there was a need to incorporate technological advances, it was considered appropriate to assemble all the information in one comprehensive document which was published in 2010 covering:

• power generation
• power management
• power distribution
• vessel management systems
• thruster drives and controls
• safety systems.

Under each topic the guide explores both early systems and more modern technologies. Some of the earlier systems are still on older vessels and their technology remains relevant. The operating principles, advantages, limitations and fault patterns of the components and systems are discussed with particular reference to FMEAs and trials and to satisfying DP equipment class functional requirements for fault tolerance.

The guidance was further revised to revision 1 and generally updated in 2016.

This revision (rev. 2) reflects a general update and discusses new subjects including hybrid technology, DC grid systems, cross connections, and incorporates a detailed section on UPS systems in replacement of IMCA M196 Guidance on the Design, Selection, Installation and Use of Uninterruptible Power Supplies Onboard Vessels which has now been withdrawn. Where deemed appropriate, theoretical or supplementary information from various sections of the guidance has been moved from the body of the document into a new appendix.

The document assumes that DP vessels will be designed and built in compliance with applicable class rules and does not reproduce these rules. Each classification society’s rules are different and they are revised on a regular basis, therefore interested persons should refer to the rules directly and contact the relevant society with inquiries about rule interpretations and points which may be unclear.

The information in this guide is relevant to a wide variety of users including:

• vessel owners and operators
• vessel designers
• equipment manufacturers and suppliers
• inspectors, auditors and consultants
• classification societies.

There will be information in this guide that is useful to managers, marine departments, vessel crew, procurement personnel, and frontline engineers. This guide contains aides-mémoire, recommendations for studies and further analysis, comparisons and other material which will promote safe and efficient DP vessels.

 

Contents

• Introduction
• Abbreviations
• Power Generation
• Power Management
• Power Distribution
• Thrusters, Drives and Controls
• Safety Systems
• Vessel Management Systems