STEADY STATE PERFORMANCE OF THE WOUND-ROTOR HYBRID STEPPING MOTOR
The permanent magnet hybrid stepping motor is one of the most widely used motors, because of its good dynamic characteristics. One of the drawbacks of this motor is the inability to regulate the rotor mmf in order to produce a family of steady-state characteristics like the orthodox synchronous motor. This paper presents the results of steady-state tests conducted on a doubly excited motor constructed out of an existing permanent magnet hybrid stepping motor. The aim was to investigate the dependence of permanent magnet mmf on the stator excitation and the possibility of the new motor to produce steady-state characteristics similar to those of the synchronous motor. The test results confirmed that the permanent magnet mmf varies with variation of stator excitation and the characteristics of the wound-rotor motor are similar to those of the synchronous motor.
Jonathan U. Agber