| 摘要 |
Even when a plurality of dispersed power generation systems are connected to a utility gride, an islanding-operation prevention apparatus can easily and assuredly prevent an islanding operation of each dispersed power supply constituting the corresponding dispersed power generation system. The apparatus includes a breaker (5) provided between the utility gride (4) and a dispersed power (1) supply, an electric-power-value detector (10,11) for detecting a value of electric power from a power line connected to the utility gride, a switch (7) for electrically connecting or disconnecting an electric-power changing device for changing the value of electric power to the power line in accordance with an output from a pulse circuit, and a controller (6) for controlling the breaker in accordance with the width of fluctuations of the value of electric power during the connection or the disconnection. A dispersed power generation apparatus and a dispersed power generation system uses such an apparatus. By further providing a synchronous circuit (12) for synchronizing the output of the pulse circuit with a signal output from a reference-signal source, even if the amount of the generated power and the amount of a load are in a complete equilibrium state during an islanding operation, the islanding operation can be assuredly prevented with a short time period until the stop of the islanding operation and without using large-scale equipment. <IMAGE> |
