LNG vessel to get PM shaft generator

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The Switch, a manufacturer of megawatt-class permanent magnet (PM) machines for marine drive trains, has been chosen to deliver its PM shaft generator for an LNG carrier with a 45,000 cubic meter cargo capacity. This is expected to allow the vessel to gain greater efficiency over its entire speed range.

(A PM shaft generator)

The order is part of a complete energy efficiency system being delivered by WE Tech Solutions (WE Tech) of Finland to Saga LNG Shipping Pte. Ltd. The vessel will be built by China Merchants Heavy Industry Co. Ltd.

The Switch received a PM shaft generator order recently with an option of one more from WE Tech for an LNG carrier owned by Saga LNG Shipping Pte. Ltd. They are likely to be delivered in October 2016.


Using the front-end low harmonic drive technology of WE Drive, the Switch’s PM shaft generator can operate over the full main engine speed range while generating electricity for the vessel’s electrical network. This feature is an advantage in electrical part loads, which is the normal electrical load condition in any ship.

WE Tech will also deliver its power distribution solution that provides the vessel’s electrical network with up to 1200 kW of electrical power in Power Take Out (PTO) mode. The delivery also features the Power Take In (PTI) mode for Take Me Home, whereby the WE Drive is used as an auxiliary propulsion drive when the main engine is not in operation. The solution also utilizes the common DC-link in the WE Drive to enable energy-efficient DC power distribution for the bow thruster.

The high-speed PMM 500 marine shaft generator will be connected to the PTO shaft of the reduction gear in the propulsion line. The Switch offers PMM 500 shaft generators in various power ranges from 0.5 to 4 MW at speeds of up to 2,000 rpm to adapt to various requirements.

Mårten Storbacka, Managing Director of WE Tech Solutions said the main advantage of permanent magnet technology is that it significantly increases energy efficiency. Depending on how you calculate it, fuel savings are approximately 20-30%. Since this technology lowers the need for installed power on a ship, energy generation and weight are reduced significantly, thereby lowering fuel consumption and the need for maintenance.