Marine Electrical Power Systems:
Shipboard Power System Fundamentals:
Power System Grounding

Last Update: November 19, 2025

Essential Questions

Essential Question Level of Thinking
What are the characteristcs of ungrounded, high resistance grounded, and solidly grounded power systems?
Understand
What are common mode voltages and currents;
how do ground faults impact common mode voltages and currents;
what are the implications of common mode currents flowing in the ship's hull?
Understand
What are separately derived systems, how are they implemented, and what are the implications of
not operating two power systems as separately derived systems?
Understand
How are ground faults detected and localized for the different types of grounding systems?
Understand
When should each type of grounding system be employed onboard ship?
Understand

Text Material

Power System Grounding

Presentation Material

Images

I_20251119a Power System Grounding Figures

I_20240921a USS Slater (DE-766) Ground Detection Lamps

Video Material

Experiment 2: Delta-Delta Transformer – ungrounded system – Ground Fault

Experiment 7: Delta-Wye Transformer – 4 wire – ungrounded system – ground

Experiment 8: Delta-Wye Transformer – 4 wire – solidly grounded system – unbalanced load and ground fault

Experiment 9: Delta-Wye Transformer – 4 wire – HRG system – unbalanced load and ground fault

Experiment 10: Wye-Wye Transformer – 4 wire – solidly grounded system – unbalanced load and ground fault

Experiment 12: Delta–Delta Transformer– HRG with zig–zag transformer – Ground Fault

Experiment 13: Delta–Delta Transformer– HRG with Wye–Delta transformer – Ground Fault

Experiment 14: Delta–Delta Transformer– HRG with Wye–Broken Delta transformer – Ground Fault

Common Mode Fundamentals – Part 1

Common Mode Fundamentals – Part 2 – Common Mode Modeling

Common Mode Fundamentals – Part 3 – Modeling CM Voltage Sources

Experiment 11: Six–pulse rectifier – common mode voltage and current – ground fault

References

IEEE Std 45.1 IEEE Recommended Practice for Electrical Installations on Shipboard--Design

IEEE Std 45.3 IEEE Recommended Practice for Electrical Installations on Shipboard--Systems Engineering

Doerry, Norbert, Mohammed M. Islam, John Prousalidis, Design of Shipboard Power System Grounding / Earthing , IEEE Press - Wiley, January 2025, ISBN-10 1119933080 ISBN-13 978-1119933083

Doerry, Dr. Norbert H., Integrated Electric Propulsion,The Marine Engineering Series Edited by Michael G. Parson, SNAME, Alexandria VA, 2020 ISBN 978-1-7923-1226-7

Jacobson, Boris, and John Walker, " Grounding Considerations for DC and Mixed DC and AC Power Systems," Naval Engineers Journal, Volume 119, Number 2, 1 October 2007 , pp. 49-62.


(C) Copyright 2024-2025 Norbert Doerry

This work by Norbert Doerry is licensed under CC BY 4.0

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