PM drive trains called “a game changer”

Marine drive train by The Switch

OCTOBER 30, 2013 — The Switch, a Vantaa, Finland, manufacturer of permanent magnet motors, generators and converters, has launched a next-generation of drive trains for energy efficient merchant vessel power generation and propulsion of merchant vessels. They combine the company’s permanent magnet and frequency converter technology. The Switch says that “this opens up all-new opportunities for hybrid propulsion systems in the shipping sector.”

Next generation electrical drive trains based on permanent magnet (PM) technology from The Switch, provide advanced control with a permanent magnet motor and a frequency converter as the major components. The controller acts as the brains for energy efficiency, keeping the network stable regardless of external conditions, such as waves, speed and other influential factors.


Calling it a “game-changing solution,” The Switch says that this enables vessels to produce electricity with better efficiency for the entire ship’s network, lower costs by keeping auxiliary generators off – and allows the main engines to operate at variable speed and generate electricity.  In total, it adds up to major operational savings for vessels with four-stroke, but in particular two-stroke, engines and helps to comply with future environmental legislations.


“Soaring fuel prices, global overcapacity and lower profit margins are forcing shipbuilders to rethink conventional power configurations,” says the company’s President and CEO, Jukka-Pekka Mäkinen. “This has opened the way for advanced technologies that are revolutionizing the way ships generate and use energy for the good of the environment. Our drive train technology is a game-changing opportunity for hybrid propulsion systems, namely in the large merchant shipping sector, where two-stroke main engines are the preferred type of prime mover. It will enable a shipowner to save up to €50,000 per month in fuel costs, which may add up to 7% more profit per year”

Permanent magnet generator technology has gained a very successful track record in many other industries. Thanks to their higher power density, PM machines can be more compact, lighter in weight and smaller in size. They have proven their high reliability and durability under extremely harsh operating conditions. The Switch PM machines deliver excellent performance with corrosion resistance and temperature tolerance.


Adding a frequency converter to a shaft generator allows a ship to control its speed and ensure a stable source of electricity for the ship’s network. The frequency converter allows the ship to choose between taking power from the main engine or from the auxiliary generators, as deemed best.


A PM machine gives high-efficiency performance over the entire operating range, significantly cutting back on fuel consumption. It is typically 2-4% more efficient at full load and 10% more efficient at part loads compared with induction machines. These efficiencies result from a lack of current losses in the rotor, the absence of an exciter, and reduced winding losses. A synchronous PM machine contains Neodymium-Iron-Boron (NdFeB) magnets, which are materials with a very high flux density, which makes them ideal for variable speed generators throughout the entire speed range. The magnetic field is created with almost zero rotor losses.

Thanks to the improved high density, the size and weight of the drive train can be substantially reduced. This leads to greater flexibility with the limited space available in ship configurations.

The Switch, together with its partners, can provide ship designers and builders with turnkey deliveries for the most energy efficient operation in the challenging marine environment. Additional services include design consultation for selectivity, project management, and the capability to deliver integrated solutions for newbuild ships or upgrades of existing vessels.

The Switch is a pioneer in advanced drive train technology based on megawatt-class permanent magnet motors, generators and frequency converter packages. The main focus areas are marine, wind, solar and special industrial solutions.  Founded in 2006, The Switch reported net sales of EUR 43.2 million in 2012.