Patent ID: 7339344

Claim:
A method of determining a plurality of parameters of a Permanent Magnet Synchronous Motor (PMSM) by a motor controller to differentiate between a plurality of PMSMs, the method comprising the steps of: applying regulated DC motor currents at a commanded fixed rotor angle; measuring a quadrature voltage v q after an initial transient has elapsed, the quadrature voltage being applied across the PMSM windings; parking the PMSM at standstill, whereby the quadrature voltage is proportional to a stator resistance and to the applied park current I park ; selecting an initial set of controller parameters; applying the quadrature voltage equal to zero; measuring a time constant T s corresponding to an exponential decay of a quadrature current i q ; accelerating the PMSM with a constant torque up to a preset target speed; measuring a total acceleration time t accelerate until the preset target speed ω target is reached; regulating a stator current at 0 value, whereby the stator current is at 0 value when currents i q(ref) and i d(ref) are both at zero value; measuring the quadrature voltage and a freewheeling motor speed ω freewheel immediately after applying the 0 stator current; calculating an electrical constant K E of the PMSM based on the measured values of the applied quadrature voltage and the freewheeling motor speed; calculating a load inertia J based on the previously measured total acceleration time; and calculating a set of parameters for the controller based on the determined motor parameters.