Method and system for judging operation state of unit isolated network by rotating speed and power imbalance

The invention discloses a method and a system for judging an isolated network operation state of a unit according to rotating speed and power imbalance, and the method comprises the steps: when a power imbalance protection action signal of the generator set appears, executing judgment: judging whether the power difference value imbalance amount of the power of the generator set exceeds a power difference value threshold value or not; judging whether the rotating speed value of the generator set exceeds a preset proportion value than a standard rotating speed value; and judging that the generator set is in an isolated network operation state when the rotating speed and the unbalanced power of the generator set meet the judgment conditions and can be kept for a preset time length at the same time. Whether the unit is in the isolated network operation state or not can be accurately determined, and the unit is rapidly switched to the isolated network operation mode. 本发明公开了一种由转速和功率不平衡判别机组孤网运行状态的方法及系统，其中方法包括：当发电机组功