Detection of sensor faults with observer structures in control loops

Electrical machines of high power scale have a redundant control electronic which might be confused by external disturbances. In this paper we propose a method to distinguish sensor failures (speed and current loops) from power supply fluctuations and load torque impacts or to be at least robust to it. The proposed technique is based on analytical redundancy: faults are represented by a variation of state variables which are estimated with the help of observer structures. We present the regarded faults of the sensors in the control loops, their detection, and we study the robustness of the approach with respect to external disturbances like load torque impacts or power supply fluctuations