| 摘要 |
PROBLEM TO BE SOLVED: To detect isolated operation at high speed.SOLUTION: A power conversion device includes: an inverter that converts DC power to AC power and performs operation by interconnecting with an AC power system; reactive power injection means for injecting reactive power into the AC power system; frequency fluctuation detection means for detecting frequency fluctuation caused by the injected reactive power; and isolated operation determination means for detecting isolated operation of the inverter on the basis of the detected frequency fluctuation. The isolated operation determination means continues to inject reactive power corresponding to frequency fluctuation generated at the time of occurrence of the isolated operation; and determines to be in an isolated operation state in the case that a state in which a frequency fluctuating as a result of the injection exceeds a certain fluctuation width continues for a predetermined period. |
