Abstract: A reciprocating engine type electric generator includes means for recognizing a phase difference between a phase of an alternate voltage wave generated at a stator coil following rotation of a rotor and a phase of a reference alternate voltage, and means for controlling a speed of a rotational magnetic field generated at the stator coil by controlling the alternate voltage applied to the stator coil based upon the phase difference recognized by the means for recognizing the phase difference.

Abstract: A reciprocating engine type electric generator includes means for recognizing a phase difference between a phase of an alternate voltage wave generated at a stator coil following rotation of a rotor and a phase of a reference alternate voltage, and means for controlling a speed of a rotational magnetic field generated at the stator coil by controlling the alternate voltage applied to the stator coil based upon the phase difference recognized by the means for recognizing the phase difference.

Abstract: A method for controlling starting of a synchronous motor having an excellent starting ability and capable of coming into a commutation mode in a short time is provided. An AC current having a predetermined frequency is supplied to a field coil 81 of a synchronous motor 8 by an inverter 91, thereby starting the synchronous motor 8. By detecting a terminal voltage of the field coil 81 of the synchronous motor 8 at the starting time, and decreasing a voltage waveform component based on the AC current supplied by the inverter 91 from the detected voltage, the waveform is corrected so that the voltage waveform component based on the counter electromotive force can be confirmed (110). And after integrating the corrected waveform (111) and converting the same into a square wave (112), a phase difference between the same (104) and an output of a 120° energization waveform generating circuit 102 is detected to be fed back.