Abstract
The magnetic properties of core materials and the core conditions were represented in equivalent circuits for motors. In equivalent circuits for motor cores, real inductance L, imaginery inductance r/j and resistance R are connected in parallel to express the frequency dependences of iron losses. L, r, R are related respectively to permeability, hysteresis loss and eddy current loss. The magnetic properties of motor cores are affected by flux distribution, rotational flux, manufacturing stress and space harmonics and time harmonics in motors, and the figures 2, 4, 5 and 6 show the circuits which represent the effects. The equivalent circuits are composed of equivalent circuits for stator, rotor and air gap, and then this equivalent circuit analysis can indicate the most suitable core materials for each part. Using this equivalent circuit, the relationships between the characteristics of motors and the magnetic properties of core materials can be investigated in d. c. motor, synchronous motor, induction motor. reluctance motor (RM) and switched RM.