The Genetic Algorithm for an Electromagnetic Parameters Estimation of an Induction Motor Secondary Multi-Loop Equivalent Circuit

Speed and rotor flux estimation based on the induction machine inductance frequency characteristic - simulation studies

“…The representation of the rotor impedance Z 2  (ω 2 ) occurring in the equation 3by a sequence of parallelconnected two-terminals composed of R • 2(n) , L • 2(n) elements (4) leads to an approximation of the actual IM inductance L 1δ (ω 2 ) frequency characteristic by means of the machine SML-EC ( Fig. 1) [2]- [5]. In this way, the approximate representation of a machine with distributed parameters by an equivalent circuit with lumped parameters is achieved.…”

“…In this way, the approximate representation of a machine with distributed parameters by an equivalent circuit with lumped parameters is achieved. The number N 0 of parallel connected R • 2(n) , L • 2(n) twoterminals of an approximated SML-EC results from required accuracy of the actual inductance frequency characteristic representation by the equivalent circuit in the considered frequency range [5]. Stator phase winding parameters R 1 , L 1 are determined analytically or through measurement.…”

“…of machine SML-EC particular two-terminals has been performed in line with the procedure described in [5] by means of the genetic algorithm in the Matlab-Simulink environment [18], while the magnetizing inductance has been determined in pursuance of the following relationship L µ =L 1δ (ω 2 =0). A strong convergence between the investigated IM inductance L 1δ (ω 2 ) frequency characteristic calculated with the use of the machine SML-EC and the one determined on the basis of conducted measurement can be observed (Fig.…”

“…The waveforms of these state variables have been determined, with the use of the scalar-controlled IM drive simulation model with the machine SML-EC, at predefined angular velocity changes (0.05ω N →ω N →0.5ω N →0.05ω N , ω N -rated angular velocity) and a constant load torque equal to the tested IM rated torque. Evaluation of operation accuracy of the considered state variables' estimators has been made on the basis of the instantaneous relative errors (5) between the values of specified motor state variables derived from the scalar-controlled IM drive simulation model and the values of corresponding state variables determined through an estimation process. In addition, the root mean squared errors (6) of the examined state variables' reconstruction have been calculated in the strictly defined time intervals resulting from the considered electromechanical transients.…”

“…Therefore an IM operation analysis, realized with the use of a mathematical model based on that characteristic, can be carried out at varying supply voltage parameters as well as at fastchanging electromechanical transients. The IM inductance frequency characteristic is well approximated by a machine secondary multi-loop equivalent circuit (SML-EC) with constant lumped parameters [2]- [5].…”