Ghazanfar Shahgholian - Department of Electrical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
Majid Dehghani - Smart Microgrid Research Center, Najafabad Branch, Islamic Azad University, Najafabad, Iran
Majid Moazzami - Smart Microgrid Research Center, Najafabad Branch, Islamic Azad University, Najafabad, Iran

Stepping motors are normally operated without feedback and may suffer from loss of synchroni-zation. The permanent magnet stepper motor (PMSM) is generally two-phase. In this paper, the nonlinear dynamic equations governing the performance of the permanent magnet stepper motor are linearized at an operating point for small signal stability studies. Small signal stability is the system ability to maintain synchronism when a small disturbance occurs. It is based on the state space averaging approach. A detailed description of the method, results, and conclusions are also presented. Finally, simulation results for three motors have been reported and compared

eigenvalues analysis, linearized model, mode system, permanent magnet stepper motor, state space