Starting from usual rated data (ηn, αη,m, cosφ1,n, sn, mM), a simple and efficient procedure is proposed for identifying T-equivalent circuit parameters of three-phase asynchronous motor. Subsequently, by numerical solving of equivalent circuit, the operating performances of a three-phase asynchronous motor supplied from voltage or current sources, at constant or variable frequency, can be obtained. A numerical example (75kW, 1485 rpm asynchronous motor) confirms the validity of proposed method and the relatively good agreement between numerical and analytical characteristics.

Keywords: Asynchronous motor, Equivalent circuit, Parameters, Performances