An offline parameter estimation method of inverter-fed induction motors at standstill based on two consecutive different voltages injection

Abstract

This paper proposes an offline parameter estimation method of inverter-fed induction motors at standstill based on a two consecutive different voltages injection. The estimation method is achieved by recording the instantaneous stator current vector and instantaneous reference voltage vector at the same rotation angle. It possesses following characteristics. Firstly, the instantaneous rotating vector is used to estimate the motor parameters. It is no longer necessary to record the data of the entire cycle, thus reducing the computational and storage burden. Secondly, in order to eliminate the effect of inverter-error-induced deviation between the actual and reference voltage vectors, a method based on two consecutive different voltage injections is proposed. The proposed method replaces the actual voltage with the reference voltage for parameter estimation. Finally, a single-phase signal vector extension method is proposed, which expands the single-phase vector into a rotating vector by constructing an imaginary axis. Thus, the estimation method using the instantaneous rotating vector can also be performed in the single-phase experiment. Therefore, the implementation of the proposed method is easy, since it does not needto detect the actual voltage and store whole-cycle data, and the estimated parameters are accurate because the inverter error is considered. Simulation and experimental results verify the effectiveness of the proposed method.