Supraharmonics in shipboard power systems: research gaps, challenges, and future directions

Supraharmonics (2–150 kHz) have become a significant concern in maritime electrical systems as ships adopt power–electronic propulsion, hybrid AC/DC distribution, and renewable energy sources. Although supraharmonic phenomena and marine power quality have been studied separately, there is limited ship–specific research focussing on supraharmonics in shipboard or marine power systems. This gap persists despite unique challenges such as isolated microgrid operation, high penetration of converters and harsh maritime conditions. To address this deficiency, this review synthesises insights from existing supraharmonic research and maritime power quality studies to examine supraharmonics in shipboard environments. It investigates the origins, propagation, and impacts of supraharmonics in ships; evaluates the applicability of current international regulations; and surveys mitigation techniques that can be adapted to space–and weight–constrained vessels. The review shows that existing electromagnetic–compatibility regulations lack explicit criteria for supraharmonic emissions, measurement, and compliance. By highlighting this regulatory gap and assessing potential filtering and monitoring strategies, the paper underscores the need for ship–specific supraharmonic standards and tailored mitigation solutions to minimise interference, enhance equipment reliability, and ensure safe marine operations.