| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply unit for motor capable of attaining cost reduction by eliminating a converter for storage and feeding of a group of capacitors for storage, and providing high reliability by preventing inrush current running through the group of capacitors. SOLUTION: This power supply unit for motor provided with a smoothing capacitor 4 connected in parallel with a rectifier 3 which rectifies a commercial AC power supply unit, and an inverter 5 which supplies a motor 7 with AC power with a variable frequency has the group of capacitors 6 connected in parallel therewith which consists of a plurality of small unit of capacitors, and has larger total capacity than that of the smoothing capacitor 4 so that the number of the small unit of capacitors may be larger than at least the number obtained by dividing the maximum output voltage value of the rectifier 3 by the withstand voltage value of the small unit of the capacitors. The power unit also includes a current inhibiting means R1 which inhibits current running through the group of capacitors 6 according to prescribed conditions, and current inhibition controlling means 21A, 31, 32, S10 which connect the current inhibiting means R1 between the terminal of the smoothing capacitor 4 and the terminal of the group of capacitors 6. |
