IEC PAS 63108:2017

Overview

IEC PAS 63108:2017 - Electrical installations in ships: Primary DC distribution - System design architecture defines principles and requirements for shipboard primary DC distribution systems and their interconnections. Published as a Publicly Available Specification (PAS) by IEC TC 18, the document addresses modern maritime power architectures that integrate multiple energy sources, energy storage and semiconductor-based power conversion while maintaining safety, reliability and reduced environmental footprint.

Key topics and technical requirements

• Scope and intent: Establishes general principles for safe operation of primary DC distribution in existing and new power generating units and novel DC concepts.
• System design architecture: Guidance on configuring DC distribution networks, combined AC/DC systems, and locations for installations.
• Power quality & transient behavior: Requirements for managing power quality, transient operation and black‑start (dead ship) scenarios.
• Protection philosophy: System studies and calculations to demonstrate selectivity, segregation methods and protective equipment for DC systems.
• Short‑circuit considerations: Assessment of short‑circuit currents in combined AC/DC installations and implications for protection.
• Energy sources & integration: Guidelines for integrating batteries, variable‑speed generation, shore charging and diverse DC power sources.
• Semiconductor converters & breakers: Use of AC↔DC, DC↔DC and DC↔AC converters, and semiconductor devices as breakers; such devices should meet applicable switchgear requirements (see IEC 60947‑2 / IEC 60947‑3).
• Control systems: Control architecture for automatic start, load sharing, reconnection and total power balance management.
• Installation, testing and documentation: Factory acceptance tests, on‑board commissioning, verification and required documentation for safe implementation.

Practical applications and users

IEC PAS 63108 is intended for professionals and organizations involved in modern ship electrical systems, including:

• Ship designers and naval architects planning hybrid or DC-centric power plants
• Marine electrical engineers and system integrators designing DC microgrids, propulsion systems and battery installations
• Shipyards and OEMs building vessels with energy storage, shore‑charging interfaces or semiconductor converter-based distribution
• Classification societies and regulators assessing compliance and safety of novel DC architectures

Typical applications include hybrid propulsion systems, battery energy storage integration, DC-based hotel and service loads, and shore-powered charging for electrified vessels.

Related standards

• IEC 60092 series (marine electrical installations) - background for traditional shipboard systems
• IEC 60947‑2 and IEC 60947‑3 - requirements for switchgear and semiconductor breaker performance

IEC PAS 63108:2017 provides a practical pre‑standard framework for shipboard primary DC distribution design, protection and control to support safer, more efficient and lower‑emission maritime electrical systems.