Integrated sensing of mechanical parameters in a micro-turbo-generator

This paper reports the in-situ sensing of multiple mechanical parameters of an integrated rotary electromagnetic micro-turbo-generator using output electrical signals. The device is designed for electrical power generation, and composed of a microturbine rotor and a stator. The rotor was actuated with pressurized nitrogen at rotational speeds up to 23 krpm, while sinusoidal voltages induced on the stator were analyzed. It is demonstrated that the rotor speed, gas flow rate, and pressure show high linearity with voltage amplitude and frequency with R² values larger than 0.97. Sensitivity values down to 83 Hz/krpm, 140 Hz/slm, and 1428 Hz/psi were achieved. This technique will reduce complexities in active device screening, and lead to integrated closed-loop control to dynamically tune the desired operating conditions of rotary microgenerators.