Targeting at demagnetization fault, this paper establishes a new analytical model (AM) and carries out comprehensive analysis for the maximum torque per ampere (MTPA)-driven permanent magnet motors (PMM) with distributed lap windings. First, the back electromotive force (B-EMF) and dynamics of the PMM are modeled based on the working properties of the motor and the Faraday\'s law of electromagnetic induction. Second, the amplitudes and harmonics of the B-EMF and currents are analyzed theoretically based on the proposed model, revealing the system performance before and after uniform and local demagnetization faults emerge.
