POWER UNIT AND POWER CONVERSION DEVICE

摘要

PROBLEM TO BE SOLVED: To protect an inrush current limiting resistor in a configuration that is simplified as further as possible, of a power unit employing a storage battery.SOLUTION: A power unit 100 includes: a DC bus 1 to which a DC load 7 is connected and a capacitor 6 connected thereto; a storage battery 5 which is charged on the basis of a voltage of the DC bus 1 and supplies power to the DC bus 1; an inrush current limiting circuit 3 provided between the DC bus 1 and the storage battery 5 and including a main cable run in which a charging/discharging current flows by closing a switch 31, and a sub cable run in which a charging current passes from the storage battery 5 through an inrush current limiting resistor 32 to the DC bus 1 while the switch 31 is opened; a protection switch 4 which is provided in series with the inrush current limiting resistor 32 and between the DC bus 1 and the storage battery 5; and a control section which cuts off the current flowing out of the storage battery 5 via the inrush current limiting resistor 32 by opening the protection switch 4 through a time-limited operation in the case where a voltage of the DC bus 1 is lower than a voltage of the storage battery 5.