PMM2000M brings highest torque capacity to new marine vessels

Early 2023 will see the first deliveries of our largest permanent magnet (PM) shaft generators to shipyards. Purpose-built for the shipping giants of the sea, the PMM2000M brings maximized torque capacity with the lowest mass and inertia to fulfill the power production needs of the very largest cargo vessels – and at the same time help them meet the latest emissions standards.

Structural integrity prioritized

Light for its meganewton-meter class torque capacity, the PMM2000M weighs below 50 tons in its shortest version. Structural integrity has been our top priority for construction design, considering the mass of this generator, its high torque and the sea-induced accelerations.

From initial concept to finite element (FE) analysis, we’ve applied the latest understanding of fatigue resistance to the design. Our team has nearly two decades’ experience producing large PM machines and has supplied over 150 PM shaft generators to the marine industry. We’ve developed the PMM2000M through many conceptual and simulation iterations.

The smallest details have been considered. For example, terminal boxes fit inside the structural envelope of the stator frame for efficient use of space, and four cooling fans ensure even temperatures and added redundancy.

The result: a simple, lean machine ready for dependable operation in the harsh sea environment.

Proven benefits of our PM machines

The PMM2000M includes all the benefits of its smaller predecessors, the PMM1000M and the PMM1500M:

  • Low-profile magnet module with hermetic design minimizes rotational inertia
  • No slip rings
  • No exciter machines
  • High partial-load efficiencies
  • Robust cooling system using water to cool air in a closed loop is resiliently mounted on top of the machine for added robustness
  • Easy-to-install design
  • Deliveries arrive factory tested with the rotor inside the stator, ready to install

We continue to make easy installation at the shipyard a design priority. We deliver the factory-tested unit as a complete package, with the rotor already inside the stator.

Once the intermediate propeller shaft is mounted to the generator, the shaft and shaft generator are lifted in one piece into the ship’s engine room for alignment as part of the shaft line. Hydraulically tensioned stud bolts allow for easy disconnect of the PM rotor for shaft line adjustments such as jack-up testing. Meanwhile, built-in features of the generator help control magnetic forces during installation and prevent collision of the air gap.

Expanding marine uses for PM machines

Since 2014, we have been delivering our smaller direct-drive shaft generators to the shipping industry for use in bulk product and car carriers, oil and chemical tankers, and LPG and LNG carriers.

Now shipowners and shipyards can meet the power production needs of their largest vessels with PM shaft generators, and the same new frame size can be used for needs of future electrical propulsion. Soon, PMM2000M machines will be powering the largest ships on the seas, forging the way to cleaner seas.

The first deliveries are rated just below 5 MW and are used in shaft generator applications using a  2-stroke main engine as the prime mover. The frame size PMM2000M has torque capacity from below 1 MNm up to 2 MNm, depending on the machine length. The lower end uses system-wise affordable low-voltage technology, and the largest machines are of medium voltage.

Get in touch to discuss the specifics of your next project!