| 摘要 |
PROBLEM TO BE SOLVED: To provide an islanding operation detection method and islanding operation detection device for implementing rapid detection of islanding operation and avoiding reduction in power quality.SOLUTION: An islanding operation detection device comprises: a frequency detection unit for detecting a frequency of AC voltage output from an AC power system and inverter 2; a frequency change rate detection unit 52 for calculating a frequency change rate; a first function unit 51 for calculating a value of reactive power to the frequency change rate by using a first function and outputting the value; a second function unit 53 for calculating a value of reactive power by using a second function and outputting the value; an addition unit 56 for adding output of the first function unit 51 and output of the second function unit 53; a &Dgr;Vcalculation unit 54 for calculating &Dgr;Vfrom voltage detected by a voltage detection unit 10; a gain control unit 55 for notifying the first function unit 51 to adjust gain of the first function when the value calculated by the &Dgr;Vcalculation unit 54 exceeds a threshold; and a drive unit for controlling output power output from the inverter 2 by using output of the addition unit 56, and stopping the inverter 2 when abnormality is detected. |
