Influence of Low Inlet Pressure and Temperature on the Compressor Map Limits of Electrical Turbo Chargers for Airborne Fuel Cell Applications

For the optimal high-efficiency operation of a PEM fuel cell system, temperature, pressure, humidity and mass flow supplied air must be tuned to stack requirements. Especially for aircraft applications, this requires thorough understanding supply system behavior how it changes when ambient pressure is below 1 bar(a) during flight. This work investigates influence low inlet pressures varying temperatures on compression map an electrical turbo charger. especially relevant in airborne application not much literature can found that topic. Compressor limits are evaluated experimentally theoretically. The theory speed correction compared experimental findings applicable surge limit investigated chargers as long compressor limited by power electric motor inverter. Based this, prediction altitudes up 10,000 m made with help developed software tool.