| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electric power conversion device that is made compact and also reduces power loss and heat generation by suppressing an overvoltage when recovering from a momentary voltage drop with simple constitution. <P>SOLUTION: The electric power conversion device includes: an AC-DC conversion circuit 2 which converts the alternating current of an AC power source 1 into a direct current; a first capacitor 3 which smooths the output of the AC-DC conversion circuit 2; an overvoltage suppression circuit 7 which is constituted by connecting a second capacitor 6 to parallel connection constitution of a diode 4 and a resistance 5 in series, and connected to the first capacitor 3 in parallel; and a DC-AC conversion circuit 8 which is connected to the overvoltage suppression circuit 7 in parallel, and converts a direct current into an alternating current. Denoting capacities of the first and second capacitors 3, 6 as C1, C2, the ratio C2/C1 of the capacitor capacities is 3 to 20, and when the AC power source 1 recovers from the momentary voltage drop, an overvoltage generated across the first capacitor 3 is suppressed. <P>COPYRIGHT: (C)2013,JPO&INPIT |
