| 摘要 |
PROBLEM TO BE SOLVED: To maintain steady-state stability of a power system by estimating, in a short time, a power phase difference angle curve for discriminating the steady-state stability.SOLUTION: A power phase difference angle curve 101 before breaker opening is changed to a power phase difference angle curve 102 by breaker opening with no accident. When breaker opening with no accident occurs, a phase difference angle δ is not changed and output power of a generator is changed, on the other hand. In accordance with a ratio of an effective power change amount &Dgr;P and an ineffective power change amount &Dgr;Q, a phase difference angle δat a time point of breaker opening with no accident is estimated and by inversely calculating a maximum power value P0#, the power phase difference angle curve 102 indicated by a sinusoidal wave function can be estimated. On the basis of the estimated power phase difference angle curve 102, the necessity of generator cut-off for maintaining steady-state stability of the power system can be discriminated. |
