To obtain a synchronous motor system capable of efficiently self- starting and synchronously operating by directly supplying a voltage from a commercial power source at a low cost.
The self-starting synchronous motor system comprises a synchronous motor 3, an inverter 2 for rectifying and converting a commercial power 1 to a DC and then frequency converting it with a semiconductor element, and a switch 4 for connecting the motor 3 to the inverter 2 or the power 1. When started, the switch 4 connects the motor 3 to the inverter 2. After the rotational speed of the motor 3 arrives at the speed capable of pulling into synchronism with a commercial frequency, the switch 4 disconnects the motor 3 from the inverter 2 and connects the motor 3 to the power 1.
USUI OSAMU
TODE YUKARI
OSHIGE TOYOMI
