Research On RB Control Strategy Of600MW Power Unit

RunBack(RB) is a function that control system of power unit to correct the fault automatically when the failure of the main auxiliary equipment occurs. RB function is good for reducing the accident so that reduce economic loss of power unit. And RB function can ensure the power plants running safety and economic. So, RB function is very important to the power unit control.The parameter of600MW power unit is high, the main steam pressure is higher than22.137MPa, and the main steam temperature is higher than540℃. The main auxiliary equipment of power plant are complicated, the inverse proportion of power unit failures which evocabled by the failure of the main auxiliary equipment is very big. RB function is complicated, requires the coordinated control of multi-subsystem. Based on the research of RB keystone and test, the paper analyses the cause of RB control failure. Combine with logic diagram, the control loops of RB are studied, including calculate loop of the main auxiliary equipment contribution, calculate loop of the power unit contribution, judgment loop of RB conditions, RB velocity calculate loop etc. The locale RB test of Neimeng Daihai600MW power plant and Datong power plant are researched in the paper. The RB test result indicates that the system, have the perfect RB control strategy, could correct the fault automatically when the failure of the main auxiliary equipment occurs, and dispense with manipulation of operator. The effectiveness and reliability of the RB control strategy were validated by the successful test and operation of the unit. RB function can ensure the power plants running safety and stability.