Aircraft propulsion systems are among the most regulated and safety-critical systems. Their design ensures that the failure rates of critical components are extremely low and that even in the event of failure of these critical components, degraded operating modes and backup systems ensure that the aircraft can continue to operate safely until landing.

This website proposes a system that is in its early conceptual phase and does not assess the airworthiness potential of the concept. However, a preliminary high-level evaluation of the Capacitive Boost Processor shows that no single point of failure can lead to a total loss of propulsion power. The proposed concept has been designed with a modular architecture in which two types of modules are used: Configurable Capacitor Modules (CCMs) and Recharge Modules. The system proposed in this paper comprises five modules in total: four CCMs and one Recharge Module. The effect of a failure of one of these five modules would result in a loss of boost functionality and the motor would operate at nominal power, where the phase voltage would be the inverter output voltage. In this degraded mode, the three remaining MCCs would be configured as pass-through, with each MCC connecting an inverter phase to a motor phase. To result in a total loss of propulsion, two bidirectional switches must fail in short-circuit mode in the same MCC and on the same side (either the inverter side or the motor side).

The severity of the transistor operating conditions, including thermal stresses due to repetitive heating and cooling, accelerate their failure. The proposed concept makes a mild use of the transistors as the switching frequency and switching currents are low. Additionally, adding the charged capacitor voltage downstream of the inverter reduces the voltage on the inverter transistors compared to having a Step-up DC/DC converter upstream of the inverter, thereby reducing the severity of use.

Finally, the modular architecture of the Capacitive Boost Processor allows for the addition of an MCC and/or a Recharge Module to the system for additional redundancy and reliability. Using each MCC and/or Recharge Module during operation would allow for the detection of latent failures.