| 摘要 |
PURPOSE:To achieve stable and accurate control, by locking a power system controller when the differentiated value of detected system frequency exceeds over a predetermined value and prohibiting unnecessary control. CONSTITUTION:Time differentiation ( f/ t) of system frequency is calculated. If it exceeds over predetermined variations L1, L2, no control is made and a controller Co is locked, thus prohibiting oversensitive control. If it is within the limits L1, L2, an interruption control command is fed to a circuit/breaker CB3 if the absolute value of the difference between the frequency (f) and a reference frequency (f0) exceeds over a predetermined judgement level (fL) while control is mode through the controller C0 if the absolute value is lower than the judgement level (fL). |
