| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect a ground fault regardless of the time of stoppage or driving of a motor in a motor controller outputting AC power by converting DC power into the AC power. <P>SOLUTION: The motor controller controls the motor 6 driven by ACs on the basis of a power supplied from a three-phase AC power supply 1. The motor controller has a current detecting section 4 detecting a current flowing through the motor 6, a detecting section 7 detecting the position of a needle for the motor 6 and an information related to the speed of the motor 6 and a current control section 5 having a U-, V- and W-phase→d- and q-axes conversion section 12 and a d- and q-axes→U-, V- and W-phase conversion section 10 and controlling the current required for driving the motor 6 on the basis of a detecting value by a UVW three-phase coordinate system detected by the current detecting section 4 and the needle position and the speed information detected by the detecting section 7. The motor controller further has a ground fault detecting section 14 detecting the presence of the ground fault of the motor 6 on the basis of the frequency component of a signal flowing through a current feedback loop between the U-, V- and W-phase→d- and q-axes conversion section 12 and the d- and q-axes→U-, V- and W-phase conversion section 10. <P>COPYRIGHT: (C)2010,JPO&INPIT |
