| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a sensorless synchronous motor drive for controlling a rotor so that the rotor stops at a prescribed position reliably upon lock energization for locking the rotor at a prescribed position when starting the synchronous motor. <P>SOLUTION: In a lock energization process when starting the synchronous motor 10, on-duty of a pulse signal inputted to a switching element Q1 of an inverter circuit 2 from a predrive circuit 4 is increased gradually based on a lock energization control signal outputted from a lock energization control circuit 5 of a control circuit unit 3 to the predrive circuit 4, thus increasing a lock current Iu flowing a U-phase drive coil Lu gradually until the lock current Iu reaches a prescribed value I2, and hence preventing a large current exceeding the prescribed value I2 from flowing the U-phase drive coil Lu, preventing out of synchronization in the synchronous motor 10, and controlling the rotor so that the rotor stops at the prescribed position reliably. <P>COPYRIGHT: (C)2011,JPO&INPIT |
