HomeMarine Harmonic Distortion Calculator

Marine Harmonic Distortion Calculator

July 31, 2026
Ship Universe Interactive Engineering Tool

Is Your Ship’s Electrical System at Risk?

Screen the concentration of nonlinear loads, identify potential capacitor-bank resonance, estimate sensitive-equipment exposure, and build a practical power-quality measurement plan before commissioning a full engineering study.

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Live one-line diagram Preliminary 0 to 100 risk score Active vs passive filter guidance Rough equipment budget
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Preliminary screening tool only. This calculator does not replace a professional harmonic load-flow study, frequency scan, short-circuit study, protection review, class review, onboard survey, or manufacturer-specific equipment assessment. Final decisions should be made by a qualified marine electrical engineer using verified system data and measurements.

Vessel electrical-system inputs

Use worst-case simultaneous loading when practical.

1 Source and main distribution

kVA
sets
V
%

2 Variable-speed drives and large converters

units
kW
kW
kW
units
kW
75%

3 Hotel loads and sensitive equipment

kW
35%
kW

4 Capacitor banks, filters and transformer details

kVAr
A
kVA
%

5 Recorded distortion, when available

%
%
Voltage distortion at the common bus and current distortion at individual nonlinear-load feeders answer different questions. A complete survey should retain harmonic spectrum, phase angle, loading, operating mode and time history, not only a single THD number.

Load concentration and exposure

Separates the main drivers behind the score.

Weighted nonlinear-load concentration

0%
Lower concentrationHigher concentration

No calculation yet.

Sensitive-equipment exposure

Low
Conditioned / separatedDirect exposure

No calculation yet.

Resonance warning flags

Approximate parallel-resonance screening for capacitor-bank interaction.

    Mitigation direction

    Preliminary active vs passive filter suggestion.

    Screen first

    Measurement before equipment selection

    The calculator will compare source stiffness, converter mix, operating variability, capacitor-bank risk and existing mitigation before suggesting a direction.

    Recommended measurement points

    Prioritized locations for a power-quality survey.

      Suggested power-quality study

      Scope increases with score, resonance and system complexity.

        Rough engineering and equipment budget

        Broad 2026 USD planning range, not a supplier quote.

        Measurement + study$0Analyzer deployment, engineering model and report
        Mitigation equipment$0Preliminary filter, reactor or drive-level allowance
        Installed project envelope$0Concept allowance before shipyard and class scope is known

        Budget excludes taxes, travel, class approval, switchboard redesign, transformer replacement, extensive cabling, shipyard access, downtime and hazardous-area requirements. Medium-voltage and large propulsion systems can materially exceed the displayed range.

        Screening report summary

        Copy, print or save the preliminary result for discussion.

        Run the preliminary screening to build a report summary.
        Method note: The calculator uses transparent engineering heuristics to rank concern. It gives extra weight to measured voltage distortion, large 6-pulse converter concentration, weak-source conditions, plain capacitor banks near characteristic harmonic orders, highly variable operating modes and direct exposure of sensitive electronics. It does not certify compliance with IEEE, IEC, ABS, DNV, Lloyd’s Register, Bureau Veritas or any flag-state requirement.
        IEEE 519-2022 overview IEC 61000-4-7 IEC 61000-4-30:2025 ABS rules and guides
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        By the ShipUniverse Editorial Team — About Us | Contact