Modeling Tools and Control Scheme for Boosting eVTOL Powertrain Performance

The power required during take-off in eVTOL aircraft can be 3-10X the average power during cruise. Thus, electric propulsors capable of meeting the peak power requirement on a continuous basis may not be ideal. We propose a commercial tool that can safely extract the transient capability of high-power electric powertrains to offer operational flexibility and increased payload. A model-based control scheme that keeps track of the state of the electrical components through the mission profile will be used to establish the actual capability of the system instead of a fixed steady state rating. Since the power rating of many of the devices are based on temperature limits which are themselves set by life projections, a high fidelity, multi-physics model, complemented with appropriate sensor data, will be used to project a safe operating region as a function of time and risk of failure. The current/torque limits of the powertrain ‘saturation’ blocks will be adjusted based on the state of the system, and mode selected. Three operating modes are envisioned: Regular mode – with traditional limits on current/power based on ratings. This is the current baseline. Enhanced mode – with current/power limits based on data from ‘digital twin’ that tracks complete state of the powertrain. Can be implemented with data from qualification tests of components. Emergency mode – relax limits further under emergency situations, consuming some life of hardware. Needs digital twin to also estimate of remaining useful life and/or risk of failure. This is future work needing a lot more data.