Christan van Dorst, Manager Technical Engineering, HyTEPS
Existing and new regulations on emissions and the environment will have far-reaching consequences for the yacht sector in the near future. As a result, we’re seeing the yacht building industry working hard on electric and hybrid propulsion systems.
The push towards electric and hybrid propulsion systems is largely influenced by global and European environmental regulations aimed at reducing carbon emissions and promoting sustainability. Legislation such as the International Maritime Organization’s (IMO) greenhouse gas (GHG) strategy, which targets a 50% reduction in total annual GHG emissions from international shipping by 2050, serves as a significant driver. Additionally, regional regulations in the European Union, including the EU Green Deal, which seeks to make Europe the first climate-neutral continent by 2050, also encourage the adoption of cleaner energy sources in maritime transportation, including yachting.
Electric and hybrid propulsion systems are necessary for yachts to comply with ever-stricter environmental regulations. Although there are no concrete legal obligations in the field of electric propulsion yet, this is the only option allowed on many waters. However, integration of batteries, DC grids, and complex electronic equipment into primary and secondary on-board systems brings new, complex challenges. Fluctuations in power supply may result in performance issues or damage. Power electronics can generate significant amounts of heat. This requires effective cooling systems. Also, power electronics can cause electromagnetic interference, which may result in problems with other on-board systems, such as navigation and communications equipment.
Ensuring a stable, reliable power supply for power electronics is crucial. It is also important to ensure that the DC grid and batteries are compatible with other on-board systems. These need to be integrated with energy management systems, navigation equipment, and other electronic installations, for example. Regular maintenance is essential for preserving batteries and DC grids. It should also be possible, for example, to carry out arc flash studies on AC as well as DC. Effectively managing the flow of energy to and from batteries is also crucial. It’s key to ensure adequate charging capacity and prevent overcharging or deep discharge, which can shorten battery lifetimes.
Recent developments in yacht accreditation focus on sustainability and technological innovation International classification societies are developing standards for the design, construction, equipping, and operation of recreational craft, paying particular attention to safety and environmental aspects. Classification agencies therefore apply strict guidelines to the safety and reliability of electrical systems. Lloyds, DNV, Benelux Veritas, and RINA have established ship capability quality standards that define acceptable distortion levels. Like the grid standards, these are targeting voltage distortion related to harmonic current injection. In the coming years, new guidelines from other standards committees will also be translated into requirements for the maritime sector. For example, work is currently underway to amend IEEE Standard 519-1992, which relates to harmonic standards.
Simulations of electrical networks are essential for accreditation by classification agencies. They enable engineers to assess the performance of electrical networks under different conditions and in different configurations. This helps verify whether designs meet classification agencies’ standards and requirements. What’s more, design flaws or vulnerabilities come to light before a network is built or deployed. In short, simulations are crucial in the process of accreditation by classification agencies, as they help ensure safety, reliability, and regulatory compliance. Based on the results, the choice can be made, for example, to use progressive and active harmonic filters and DC-AC sine wave converters. These play an important role in ensuring clean, reliable power. 12 V or 24 V DC stored in batteries is converted to 230 V AC, so that marine systems can continue to operate at sea.
Inspansion at sea
Identifying and resolving PQ issues in a smart way ensures the reliability and safety of systems on board, and also plays a role in optimizing the lifespan and efficiency of batteries. Continuous insight into measurement data ensures more power can be extracted from electrical systems. However, this approach – which we call ‘inspansion’ – requires specialized knowledge and equipment. This can introduce challenges on yachts, which are equipped with complex electrical systems. These may include different types of loads and power systems, such as generators, inverters, and batteries. Navigation, communication, and entertainment systems may cause electromagnetic interference, affecting PQ.
A yacht is a dynamic environment that is constantly in motion and subject to changing external conditions. This makes monitoring PQ far more complex than in electrical environments that are standardized to a degree. Depending on the equipment and systems used, on-board loads vary greatly. This can cause significant fluctuations in power quality, such as voltage dips, harmonics, and flicker, all of which need to be carefully monitored.
Meeting regulatory and safety standards for accreditation by classification agencies requires close monitoring and management of PQ. Professional measurements, analyses, and recommendations make that a whole lot easier. In order to design, install and maintain maritime battery systems that ensure safety, efficiency, and reliability on board, it is essential to seek out informed advice and work with experienced experts who are familiar with the unique challenges of installing power electronics in a marine environment.