| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a means for reducing latency between power shutoff of a trunk transmission power system during grid connection and determination of islanding. <P>SOLUTION: An islanding determining device 5 determines islanding of a DC generator 2 for supplying AC power, converted by an inverter 3 in cooperation with a trunk transmission power system 1, to a load device. The device is provided with two convergent calculation means 11, 12 that have different convergence speeds when output is converged to a changed frequency if a frequency of the voltage waveform of an AC voltage from the inverter 3 is changed. When the absolute value of a difference between two output values output from the convergent calculation means 11, 12 in a convergence process of convergent calculation means 11, 12 exceeds a predetermined determination threshold, the islanding of the DC generator 2 is determined. <P>COPYRIGHT: (C)2011,JPO&INPIT |
