Method and apparatus for controlling a synchronous motor

摘要

In the synchronous motor controlling apparatus and method of the invention, a current is detected and subjected to coordinate transformation onto gamma-delta axis assumed for the rotor. A correction term is obtained on the basis of the derived current and an arbitrarily given correction current instruction. A gamma-delta axis voltage instruction is computed by adding a value obtained by multiplying the correction term by a proper gain to a voltage equation in a steady state of the synchronous motor. Consequently, a control method of small computational load, which does not require gain adjustment according to the inertia of a motor load, can be attained.