A low power NFC data over power acquisition system for high speed Electric Motor Rotors

Temperature monitoring is a key aspect in the field of electric motors. In high performance applications the rotor of a motor can reach very high temperatures leading to an over-heating of the rotor magnets, which can consequently lead to a demagnetization or to stator windings deterioration. These kinds of issues can severely impact the lifetime of an electric motor, and it is for such matter that is really important to monitor rotor temperatures: this way the motor can always be operated in a safe state, minimizing unexpected faults. Since minor errors in the simulation phase can lead to severe faults it is important to trust the simulations implemented, and this can be done by monitoring real data on the field. Such data can also be used to improve the simulation tools used to validate the motor design phase.The measurement system proposed in this paper is meant to be installed inside the motor rotor and can measure up to 8 thermocouples (type K, J, T, N, S, E, B and R) with a sampling frequency of 8 samples per second and an accuracy of ±2°C for temperatures between 0°C and 250°C. The board placed inside the rotor is powered by means of NFC energy harvest. The NFC protocol is also used to transfer data to a board placed on the motor stator.