| 摘要 |
PURPOSE:To make it possible to detect a phenomenon of vibration at each generator, by adding a differential in phase angle at each generator to a phase angle in a stationary state, and judging from a vibration or a phase difference detected thereby whether the generators are synchronized or not. CONSTITUTION:A voltage measurement and detection unit 3 detects a differential from a stationary state in phase angle at each generator 2 on the basis of a voltage waveform measured in the vicinity of the generator 2. The differential in phase angle is always transmitted to a central processing unit 4, which adds it to a stationary phase angle. In a vibration detection and judgment unit 5, a relative vibration between the generators 2 is detected on the basis of a variation in phase angle at each generator 2, and then a difference in phase angle between the generator 2 is calculated. When the difference in phase angle has a tendency of divergence and exceeds over a threshold value, a step-out state is determined from these conditions. In this way, a phenomenon of oscillation at each generator 2 can be detected. |
