Wright Electric has finished assembling its second-generation megawatt-class motor, the WM2500, writes Nick Flaherty.

The motor has been built with support from the US ARPA-E ASCEND research programme and NASA, and it is spinning freely after being assembled in December.

The 2.5 MW motor has more than 3300 bhp and is specifically designed for electric aircraft engines. It has a peak power of 2 MW at 800 VDC and 2.5 MW at 1200 VDC from eight high-frequency integrated inverters, each rated to 250 kW. These use in-slot cooling to achieve efficiency of 99.5%. Running at a speed of 7,500 rpm, the motor produces 2,550 Nm of rated torque.

The WM2500 is designed to replace the engine core of a jet engine, enabling existing aircraft with over 100 passengers to be converted to electric operation. It can directly drive a ducted fan or power a propellor through a single-stage gearbox, and it forms the core of a C-130 hybrid-electrification programme. This is converting a Hercules aircraft to hybrid operation with two electric engines and two conventional ones.

The motor can also be used as a 4 MW class turbogenerator.

The WM2500 is now undergoing testing at the Wright laboratory in Albany, US, before heading to NASA’s NEAT facility for altitude chamber testing. Propulsion test-stand testing will follow with aircraft ground and flight testing.

Wright Electric has developed its own aircraft engine test cell to characterise the performance of megawatt-class electric aircraft propulsion systems using the C-130 propellors.