| 摘要 |
PURPOSE:To prevent turbine tripping when a small earthquake is detected by a seismometer, by changing over the present filter to a filter for earthquake capable of cutting a signal up to comparatively high frequency components of a shaft vibration and to promptly trip a turbine in case of a big earthquake to protect a turbine. CONSTITUTION:Each output signal from each of shaft vibration detectors 5a-5n, detecting shaft vibration of a turbine shaft, is converted by means of a turbine monitor board 7 and inputted to a low frequency cut filter 8a or a filter 8b for earthquake through a filter changeover switch 23. Said switch 23 performs changeover by means of a relay 22 energized according to output signals from the plural number, for example, 2 sets-8 pieces, of seismometers 20a-20d, 20w- 20z provided on a generator base stand 1. A turbine trip device 13 is put in operation according to a result of judgment on magnitude of displacement quantity by means of a vibration relay board 11 which inputs signals via the filter 8a or 8b, or, it is put in operation in case of a large-scale earthquake through closing a switch 26 by means of a relay 24. |
