Fresh off the announcement about Wright's WM2500 2.5 MW motor spinning freely (earlier post), Wright announced that its WV250 aerospace inverter, built with support from ARPA-E and NASA, is also running. Designed to pair with WM2500, WV250 is a 250 kilowatt (kW) ultra-lightweight and ultra-efficient inverter designed for aerospace applications up to 40,000 ft.

Inverters are a key part of any electric propulsion system: they convert DC electricity from batteries/fuel cells into the AC electricity that motors use, and they regulate the flow of electricity to the motor. At a more practical level, they impact the powertrain in two ways:

• Weight: Each WM2500 motor has eight inverters (this is for redundancy—if one fails, there are seven still running). The current inverter test article weighs 17 lbs and has a specific power of 35 kW/kg with a path to further reduce mass. An aircraft such as Elysian’s, with eight megawatt (MW)-class motors, might have 12 MW of installed power, for a total weight of 960 lbs of WV250 inverters. Existing aviation inverters might be 14 kW/kg. This means that aircraft using Wright’s inverters can save up to 1,000 lbs. They can use this extra capacity to carry extra passengers, cargo, or batteries.

  
  

  The black boxes are the inverters on the WM2500.

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• Efficiency: Wright’s inverter is designed to be 99% efficient. Other aerospace inverters are 97% efficient. In a 12 MW powertrain like the one described above, this 2% delta can mean 240 kW of heat that would otherwise have to be dissipated using heat exchangers. Wright’s 99% efficient inverters reduce the need for heavy and un-aerodynamic heat exchangers, further reducing weight.

Wright is testing WV250 with its first generation motor initially as it conducts parallel testing with its WM2500 motor. Once the company has tested each component separately, it will integrate WV250 with WM2500 for a complete package.