A SPICE model for a novel brushless adjustable-speed drive

A SPICE circuit model was developed to accurately simulate the i-v characteristics of a brushless AC motor commutated by semiconductor switches. The model is based on Fourier curve fits to measured mutual inductance interactions between all combinations of field and armature windings, as well as coil resistance and inductance. The model is able to accurately predict current and voltage characteristics, both statically, and dynamically when interfaced with a commutation model. The model has been demonstrated to agree with electrical tests of an inverted motor on a large time scale. It has also given reliable predictions of small time-scale details, where it is desirable to predict power MOSFET switch behavior after a command to open or close. Data were collected and analyzed for simulations of the motor model combined with a commutation model containing MOSFET switches. Metrics were compared to data collected from an inverted brushless motor with good agreement.