| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor drive unit capable of switching a connection condition in the wiring of a stator without stopping rotation. <P>SOLUTION: This motor drive unit switches the connection condition in the sets of wiring U1 to W1, U2 to W2 of the stator 6 of a permanent-magnet synchronous motor 1 by a switch 3 for selecting the connection condition in the sets of wiring U1 to W1, U2 to W2 optimized, according to a rotation speed, thereby achieving high efficiency for a motor. Especially, this motor drive unit stops application of a voltage to the permanent-magnet synchronous motor 1, to switch the connection condition in the sets of wiring U1 to W1, U2 to W2, while the permanent-magnet synchronous motor 1 is coasting. This enables switching of the connection condition in the sets of wiring U1 to W1, U2 to W2, without having to stop the operation of an air-conditioning refrigeration apparatus that has with the motor drive unit 7 installed. <P>COPYRIGHT: (C)2008,JPO&INPIT |
