Coordinate transformation for an asynchronous, machine, and time discretization of a state observer

A state observer was designed, realized and tested for the rotor flux determination of an asynchronous machine, supplied via a voltage inverter. A coordinate transformation of the input signals from the stator system to an arbitrary intermediate system was realized. The transition from a time continuous model of the state observer to a time discrete model was investigated. The application of the state transition model seems to offer good prospects. A method of computing the state transition matrix based on the Sylvester expansion theorem was developed. The stability of the digital state observer in the case of constant angular velocities of the rotor and the intermediate system is discussed.