Parameter estimation for induction motor field oriented control using a non-linear motor model

For high performance control of induction motors, an adequate motor model is of utmost importance. In this paper, a parameter estimation algorithm is described which is especially suited for the estimation of the rotor parameters of a squirrel-cage motor, both in a direct and an indirect field oriented control set-up. The rotor parameter values are calculated from the voltage response induced by DC current injection of the motor at standstill. From this test, the rotor resistance and the magnetizing inductance can be calculated. The magnetizing inductance itself is fitted to the nonlinear `tanh(x)´ curve with only 2 parameters