| 摘要 |
PROBLEM TO BE SOLVED: To provide a protection means for a three-phase four-wire alternating-current power source at the time of phase interruption through a low-cost construction. SOLUTION: The neutral point power line 9n and the phase-R power line 9r of a three-phase four-wire alternating-current power source is connected with a control circuit means 2. The phase-S power line 9s and the neutral point power line 9n are connected with an inverter control means 3. The phase-T power line 9t and the neutral point power line 9n are connected with the exciting coil portion of a second three-phase power supply switching means 11 through the switching portion of a first three-phase power supply switching means 10. Whichever phase is opened in at least three-phase four-wire power lines, the switching portion of the second three-phase power supply switching means 11 is caused to perform opening operation to interrupt power supply. COPYRIGHT: (C)2006,JPO&NCIPI |
