| 摘要 |
PROBLEM TO BE SOLVED: To appropriately select and stop electrical equipment according to a frequency reduction speed by inputting the order of electrical equipment to be stopped to a selection-stopping device in advance, and turning off a proper number of electrical equipment at an appropriate timing according to the reduction speed of the frequency. SOLUTION: A frequency that is detected by a transformer 2 for a measuring instrument which is connected to a power supply system in a field, when an external power system is separated from a field power system by a main transformation switcher 1 is converted into a signal, where a selection-stopping device 10 can enter by a frequency converter 9 that is connected to the secondary side of the transformer 2 for a measuring instrument and is inputted to a frequency input device 11 of the selection- stopping device 10. Then, when frequency drops to a measurement start frequency, that has been inputted in advance, measurement is started and the reduction speed of the frequency is determined, according to the frequency deviation of operation measurement time by an operation equipment 15. The operation equipment 15 determines which selection stop frequency the frequency deviation corresponds to and the signal is outputted accordingly, thus opening a timing to be broken and a target electrical equipment power supply switcher 6. |
