| 摘要 |
PROBLEM TO BE SOLVED: To prevent an overvoltage on the DC input side of a power conversion device, based on a reverse charging operation from a system power supply in a linkage state, immediately prior to the start or immediately after the finish of a distribution line construction operation. SOLUTION: A capacitor 18 for power supply, which is installed on the DC input side of an inverter (power converter) 10, is provided. A diode 16 for a charging passage, by which a charging current based on a secondary battery (a DC power supply) 3 is injected into the capacitor 18, is provided. A switching semiconductor 24 for a discharge passage a pair of output terminals of which are connected in opposite parallel manner to both ends of the diode 16, and by which the discharge passage of the overvoltage charging energy of the capacitor 18 is formed by a switching operation, is provided. A discharge control means, which monitors a voltage or the like across terminals of the capacitor 18, which turns on and off the semiconductor 24 when the voltage across the terminals exceeds a set voltage due to a reverse charging operation from the inverter 10 immediately prior to the start or immediately after the finish of a distribution line construction operation, and which discharges the overvoltage charging energy of the capacitor 18 to the secondary battery 3, is provided. |
