New Shaft Generator Technology Boosts Marine Energy Efficiency

[By: ABB]

The latest in-line shaft generator from ABB will enable ship operators to benefit from the efficiency, performance and reliability advantages of permanent magnet technology. The new generator brings flexibility and ease of installation to a wide range of vessels including bulk carriers, container carriers, liquid natural gas tankers and ferries transporting passengers and cars.

The AMZ 1400 permanent magnet shaft generator is optimized for converter control and enables better efficiency than either induction or electrically excited synchronous machines at both full and partial loading. This helps to cut fuel costs by up to 4 percent, offering a payback period of two to four years. It also significantly reduces CO2 emissions by several tons for each day at sea.

Its compact size shrinks the footprint of the equipment package by around 20 percent compared to a conventional synchronous or induction type shaft generator. At the same time, the weight is reduced by around 30 percent. The unit is also simpler to install at the shipyard, as the intermediate propulsion shaft is mounted to the generator and then lifted into the vessel for the alignment.

Juha-Pekka Kivioja, ABB Global Product Manager, Large Motors and Generators, said: “ABB permanent magnet technology has proved to be inherently reliable over three decades in large motors and generators, especially in offshore wind turbines and propulsion applications. Applying it to shaft generators is a significant step in helping vessel energy systems to align with the goals set out in the International Maritime Organization (IMO) for Energy Efficiency Design Index (EEDI), Energy Efficiency Existing Ship Index (EEXI) and Carbon Intensity Indicator (CII). Its potential to increase energy efficiency makes the permanent magnet shaft generator an important method for reducing emissions for larger vessels.”

There are three possible modes of operation for the shaft generator in conjunction with the main propulsion engine. In Power Take Out (PTO) mode it supplies the main power for the vessel’s electrical network. This optimizes the use of the large engine, while reducing the need to run auxiliary generators, saving on fuel costs and lowering emissions.

In Power Take In (PTI) mode the shaft generator acts as a synchronous motor for an additional power boost for propulsion. It can also provide Power Take Home (PTH) for emergency propulsion should the main engine fail.

The permanent magnet shaft generator and drive combination can also power thruster motors, enable shore to ship connections and connect other DC power sources or DC power consumers. Under its first order, ABB will supply the permanent magnet shaft generators for a fleet of twelve 210,000 dwt dual-fuel bulk carriers owned by Bermuda-based Himalaya Shipping.