Accurate and Simple Diagnosis Algorithm for Inter-Turn Fault in the BLDC Motor

Inter-turn faults (ITFs) cause significant changes in the electric and magnetic characteristics of the motors. In particular, the ITFs can be the cause of serious distortions in the magnetic field of an air-gap because the inductance of the motor changes the operating conditions as a result of magnetic saturation and cross-coupled magnetization effects. Thus, an ITF diagnosis method is strongly needed in many motorized applications. This study proposes a simple diagnosis algorithm for the detection of ITFs and developed the diagnosis circuit to apply the proposed algorithm. Using magnetic characteristic analysis under an ITF, the developed diagnosis circuit calculates by an induced voltage from the detection coil and can detect the phase/region of fault. Additionally, the proposed diagnosis algorithm is verified by a simulation and an experiment.