| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a step-out detecting apparatus capable of surely detecting a step-out among a group of generators at both sides of interconnected lines in a power system, irrespective of the predetermined difference in phase angles. <P>SOLUTION: The step-out detecting apparatus 6 in the power system has an analog/digital converter 7 for fetching a voltage V and a current I at a power cable 3 in the power system 1a; an average calculating means 96 for calculating the average of the voltage and the current, at a predetermined region up to a deciding point, based on the fetched voltage and current; a maximum/minimum decision storing means for obtaining the maximum and the minimum in the average of the voltage and the current, and for storing them; a phase-angle difference calculating means 98 for calculating the difference in the phase angle from the voltage and the current; and a step-out deciding means 101 for deciding the power level as becoming step-out, in a predetermined region at the center of the minimum of the average voltage stored by the average of measured voltages and in a predetermined region, at the center of the maximum of the average current stored by the average of measured currents, when the difference in the phase angle exceeds 90°. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
