NASA Gas Flow

NNC07CA12C – Wide Output Range Power Processing Unit for Electric Propulsion

Phase I – Prototype

CPE has developed wide-range multi-phase resonant converters than can deliver full power over a 5:1 output voltage range. This enables Hall thrusters to be operated with high thrust at low output voltages or high specific impulse at high operating voltages.

The 4kW discharge module has a specific power of 0.564 kW/kg. In addition, CPE has also developed a 10kW power processing unit with 0.91 kW/kg specific power and a peak efficiency 97.9%.

Phase II

CPE resonant converters have low voltages across the power semiconductors. This greatly reduces the probability of single-event failures. The converters are suitable for a variety of aerospace applications including electric propulsion.

Phase IIE/III – Engineering and Manufacturability Upgrade

In 2015, operation of the Gas Flow PPU was successfully demonstrated at NASA GRC’s testing facility, confirming that it has reached Technology Readiness Level (TRL) 5. In 2016, NASA GRC and CPE presented “Performance of a High-Fidelity 4kW-Class Engineering Model PPU and Integration with HiVHAc System” to the 52nd AIAA/SAE/ASEE Joint Propulsion Conference, documenting their findings and conclusions.

Work is now progressing to complete a qualified TRL-6 unit.

Phase IIE/III (TRL 5) Component Validation in Relevant Environment (Thermal Vacuum Testing)

Module full-power output operating ranges

PPU ModuleOutput
Voltage (VDC)
Current (A)
Power (W)
Additional Features
Keeper/Ignition5 to 40V2.5A@40V
Heater1 to 20V10A@20V
Dual Magnet (per supply)5 to 40V5A@40V
200W Polarity Reversing Relay
Discharge/Anode200 to 700V5.71A@700V
Input Voltage Range80 to 160V