| 摘要 |
PROBLEM TO BE SOLVED: To provide a single operation detection system capable of detecting a single operation state of a distributed power source in a short time.SOLUTION: An active type single operation detection system comprises frequency detection means 12, frequency deviation calculation means 13, ineffective power calculation/injection means 14 and single operation detection means 16. The ineffective power calculation/injection means 14 injects such ineffective power that a frequency deviation to be next calculated is changed in a predetermined ratio relatively to one frequency deviation, through an inverter 11 to a sequence 21. The single operation detection means 16 calculates a ratio of increase/decrease of a present frequency deviation from a past frequency deviation as a deviation ratio. If the number of times for the deviation ratio to exceed a first threshold as a ratio threshold that is estimated from the injection ineffective power, exceeds a second threshold as a number-of-times threshold, it is discriminated that a distributed power source 1 is in a single operation state.SELECTED DRAWING: Figure 1 |
