| 摘要 |
A turbine control system incorporating a speed monitoring system for generating an actual turbine speed measurement for control of turbine speed and load is disclosed. The speed monitoring system employs two identical speed channels each of both analog and digital form and a third channel of only analog form. The two identical speed channels of digital form and the third channel of analog form are coupled to a programmed digital computer based process controller for use in controlling turbine speed and load. The two identical speed channels of analog form and the third channel are coupled to an overspeed protection controller for use in preventing turbine overspeed. Within each controller, an identical channel is selected without preference to be used as the actual turbine speed measurement. A transfer between identical speed channels will only be performed if a malfunction is detected in that identical channel utilized as the actual turbine speed measurement. This transfer will be performed without affecting the operation of the turbine as controlled by either of the two controllers. The malfunction of any two of the input channel forms to a respective controller disables only the speed control function of that controller. |
