Study on Optimization of PID for Feed-water Control System of RB Test in PWR Nuclear Power Station

During the commissioning of Nuclear power plant unit, it is necessary to perform the transient condition test that the single pump operation of Main Feedwater (APA) pump triggers the rapid load rejection of steam turbine. Due to the sudden loss of a main water supply pump during the test, the level of the steam generator will change dramatically. If there is a signal of "SG level low plus steam / water flow mismatch" or a signal of "SG level low low", the reactor trip protection will be triggered. PI controller is used as the core controller of the main feed water pump control process. The optimal parameters of PI controller directly affect the level control performance of steam generator. At present, the units that have completed the test only verify that the control system meets the requirements of transient conditions, but it does not solve the phenomenon that the oscillation frequency of the feed water regulating system is too high under stable conditions. In this paper, the safety range of the control parameters under transient condition is determined by simulation model test, and then the steady-state performance of the parameters is improved by field test, so the optimization of the control parameters is completed, and the regulation performance of the feed water control system under single pump operation and steady-state condition of the main feed water pump is improved, and practical results are achieved. The results show that the optimization of the controller parameters in this paper can meet the requirements of transient conditions, and can effectively increase the stability of the control system. This research method has been successfully applied in generation II unit, and it is also useful for the generation-III unit.