DC biased stimulation method for induction motor parameters identification at standstill without inverter nonlinearity compensation

A general stimulation method is proposed to identify induction motor (IM) parameters based on inverter at standstill without the need of inverter nonlinearity compensation. Inverter non-linear characteristics are one of the major sources of parameters identification inaccuracies because the voltage error caused by inverter nonlinearity is difficult to compensate for accurately. To overcome the influence of inverter nonlinearity, a dc current bias is added to single phase ac stimulation, which is a common stimulation style of many identification techniques. To prove the effectiveness and universality of the method, it is applied to two kinds of practical offline parameter identification techniques in literatures. One is the recursive least-squares (RLS) technique and the other is impedance equations set technique. Identification results in both simulations and experiments are given to validate the method.