Abstract: A system and a method of transforming a gain and an integral time constant of a proportional-integral (PI) controller according to a timer lapse time to relieve an excessive phenomenon of a steam generator level caused by rapid changes in open degrees of a downcomer feed-water valve and an economizer feed-water valve when reactor power transfers between low and high power sections. Accordingly, an excessive phenomenon of a steam generator level is relieved at a transfer time when reactor power transfers between low and high power sections. Therefore, a possibility of a stop of a reactor caused by the excessive phenomenon of the steam generator level is reduced to relieve burden on an operator and improve an operation rate and economic feasibility of a nuclear power plant.

Abstract: A system and a method of transforming a gain and an integral time constant of a proportional-integral (PI) controller according to a timer lapse time to relieve an excessive phenomenon of a steam generator level caused by rapid changes in open degrees of a downcomer feed-water valve and an economizer feed-water valve when reactor power transfers between low and high power sections. Accordingly, an excessive phenomenon of a steam generator level is relieved at a transfer time when reactor power transfers between low and high power sections. Therefore, a possibility of a stop of a reactor caused by the excessive phenomenon of the steam generator level is reduced to relieve burden on an operator and improve an operation rate and economic feasibility of a nuclear power plant.

Abstract: Provided are a method and apparatus for validating dynamic performance of a control system of a nuclear power plant in operation, without performing a power ascension test. According to the present invention, when the performance of the control system requires to be validated in order to change a control logic or its setpoint of or to replace hardware of the control system, the dynamic performance of the control system may be validated without performing the power ascension test which can be performed only in a trial operation and requires large expenses. In the present invention, a design computer code capable of simulating a transient state of the nuclear power plant is connected to the hardware of the control system, and tests to be performed at the power ascension test or in the transient state of the nuclear power plant are simulated by directly using the hardware of the control system instead of a control system model of the design computer code, in an on-line state.