Analysis And Implementation Of RunBack Function For Power Plant

With the rapid development of electric power technology, the capacity of units becomes larger and larger. At the same time, the control requirement of the operation parameters and the capacity automatic processing after failure is accordingly increasing. So the units also need higher automatic adjusting ability and fault-correcting ability, only depending on the manual operation is bound to cause the units and equipments unstable. It has been unable to meet the control requirements. RunBack(RB) is a function which controls the system to correct the fault automatically when the failure of the main auxiliary equipments such as ID Fans^FD Fans and so on. RunBack function is very important to the improvement of the efficiency and stability of the unit.The design purpose of the RB function of the Coordinating Control System(CCS) is to guarantee that the load will be automatically forceed down to the planned load till at the units permit by he coordinative action of the DCS control systems including the Coordinating Control System, Furance Safety Supervising System(FSSS), Sequence Control System(SCS) and Steam turbine control System(DEH) when the auxiliary equipment failure, and that once the load reaches the target, the auxiliary equipments will run safety, economically and stably. RB function can not only test the condition or performance of the CCS or other automatic control systems or their anti-interference ablity, but also analysis and optimize their control circuits and make the thermos-control system work under the best condition, which enables the load control for the whole course.Now, a lot of the electric power plants and study organizations are studying on the CCS RB function. And it has already come into use in some plants. Judging from the condition of its functional finish condition, the automatic level of the actual tests is still low and only manage not to make the fire of the furnace go out or the unit trip. Based on the condition, the units can run automatically completely. My plan is not only to guarantee the unit to restore the normal working condition when all the control systems are in order, but also to ensure the units to fullfill the task of cutting off the coal feeder and reducing the load automatically when some parts of the automation of the unit are not working, thus, it helps the operator to keep the units stable.