Compact DC-Based Power Distribution System for Smaller Marine Vessels

June 02, 2019 by Scott McMahan

ABB launched the Onboard Microgrid based on the technology from its power distribution system Onboard DC Grid™, with the company says has the proven ability to enable up to 20% energy efficiency in larger vessels.

With the launch of the new compact solution, ABB makes similar efficiencies achievable for smaller, lower-power vessels operating over short distances. Onboard Microgrid can be used aboard vessels running on batteries, fuel cells, or as fuel cell/battery hybrids.

Similar to the company's Onboard DC Grid, Onboard Microgrid allows for the flexibility of drawing on multiple energy sources and variable speed drives to optimize operating efficiency. As a result of the increased efficiency, the system can cut emissions. Onboard Microgrid connects all dc links and distributes the power through one main DC circuit, providing significant power savings and optimizing the vessel's propulsion.

Also, Onboard Microgrid reduces the footprint and weight of the electrical equipment by eliminating the need for bulky transformers and main switchboards. That leaves more space and increases flexibility in the positioning of system on board, the company points out.

The first Onboard Microgrid installation has already been given the go-ahead in an extensive hybrid conversion for San Cristoforo, a 386-tonne passenger and car ferry sailing in Lake Maggiore in Italy and operated by Gestione Navigazione Laghi.

ABB Onboard Microgrid with open panels

According to ABB, the compact system will enable the ferry to make the best use of available power via the pooling hotel and propulsion power sources with the use of a dc-link. With that, generator sets or batteries can be deployed based on user needs, in either diesel, hybrid or electric modes.

"Onboard Microgrid will allow San Cristoforo to maximize the efficiency benefits of hybrid propulsion," said Alessandro Acquafredda, General Director, Gestione Navigazione Laghi. "It also allows for better utilization of space in the engine room and is time-efficient and straightforward to install."

"Onboard Microgrid addresses a specific segment of the market, with smaller vessels playing an important role in shipping's electric, digital and connected future," said Juha Koskela, Managing Director, ABB Marine & Ports. "Bringing Onboard Microgrid to market shows how closely ABB has been listening to owners in the inland waterways vessel, ferry, workboat, tugboat and yacht markets seeking to benefit from hybrid propulsion."

Like the company's previously released Onboard DC Grid solution, the complete Onboard Microgrid solution includes a programmable controller to implement the company's power management system and generator start-up, propulsion speed control, generator overload protection. It also offers control and supervision of operating modes, battery load control, and signal handling.