A Robust Method for Induction Motor Magnetizing Curve Identification at Standstill

Modern electric drives use a self-commissioning procedure to precisely identify motor parameters for achieving high-performance control. Typically, the induction motor magnetizing curve is identified using no-load rotational test. However, some applications necessitate the electric drive to identify the magnetizing curve at standstill conditions. As one of the well-known standstill approaches, the traditional flux integration exhibits several practical problems. Any imperfection in measured current, estimated stator resistance, and dead-time compensation directly affects the accuracy of the estimated magnetizing curve because of error accumulation in open-loop integration. This paper proposes a robust yet simple solution against those practical concerns. It can identify the magnetizing curve without using any dead-time compensation and stator resistance. Only industry-standard dc-link voltage and phase current measurements are used. Its superior features are experimentally verified on a number of motors and the results are confirmed by no-load rotational test results. Its robustness against current offset and extra longer integration duration is also proved.