Parameter Estimation of Permanent-Split Capacitor-Run Single-Phase Induction Motor Using Computed Complex Voltage Ratio

Equivalent circuit parameters and performance variables of permanent-split capacitor-run single-phase induction motor can be obtained from dc test, no-load test, locked-rotor test, and using turns ratio as derived from the winding ratio test (the last one is carried out if the design data are not available). In this paper, turns ratio has been replaced by a computed complex voltage ratio, based on an assumption that single-phase motor for parameter transformation can be represented as an ideal transformer. The equations for this complex quantity have been derived that provide an alternative to winding ratio test, which otherwise requires the tedium of a physical test on the motor. The performance variables like input current, power factor, and power consumed by the motor, obtained by the proposed technique, have been compared with those obtained using the conventional techniques as well as with the experimental observations obtained on three fan motors of different ratings. It is observed that the proposed method gives performance variable values closer to the experimental observations in comparison to those obtained using the conventional methods.