| 摘要 |
PURPOSE:To determine an appropriate set point automatically depending on the conditions of power system or operating conditions thereof and to modify the set point thus determined automatically to a calculated set point. CONSTITUTION:A system condition/trend grasping/processing means 16 takes in system data of a protection object relevant to a decision object value and grasps the trend of variation of the system data, and set point calculating means 17, 31 calculate set points of decision object values automatically based on thus grapsed results of trend. Consequently, work for calculating set points variable with time can be alleviated. Furthermore, work for setting the set points can also be alleviated by modifying to thus calculated set points. When thus calculated set point is used as a subset point independently from a main set point and each set point is compared with the decision object value, such trend as may cause failure can be detected in early stage based on the comparison results. |
