Abstract: Mathematical model of double-fed motor was analyzed and relationship between stator current and rotor current of the motor was derived theoretically. Double-variable cycloconverter was used to provide frequency conversion excitation power for double-fed motor, and rotor current was controlled by controlling amplitude and frequency of output voltage of the converter. The impact of rotor current on stator power factor of double-fed motor was studied experimentally, and conclusions was derived that power factor of the motor can be adjusted by controlling rotor current.