Nuclear Steam Generator Water Level Research Articles

Research on Fuzzy PID Adaptive Control for Steam Generator Water Level

In order to overcome shortcomings of the traditional PID control for nuclear steam generator water level, we proposed a fuzzy PID control system by using fuzzy reasoning. By summing up the experience of skilled operators, we gave a set of fuzzy control rules, and determined some important control parameters. To verify the effectiveness of fuzzy PID control, a simulation for a steam generator in Qinshan nuclear power plant, for example, was given. Simulation results show that the method can effectively improve the control quality.

Multi-model predictive control method for nuclear steam generator water level

The dynamics of a nuclear steam generator (SG) is very different according to the power levels and changes as time goes on. Therefore, it is an intractable as well as challenging task to improve the water level control system of the SG. In this paper, a robust model predictive control (RMPC) method is developed for the level control problem. Based on a multi-model framework, a combination of a local nominal model with a polytopic uncertain linear parameter varying (LPV) model is built to approximate the system’s non-linear behavior. The optimization problem solved here is based on a receding horizon scheme involving the linear matrix inequality (LMI) technique. Closed loop stability and constraints satisfaction in the entire operating range are guaranteed by the feasibility of the optimization problem. Finally, simulation results show the effectiveness and the good performance of the proposed method.

원전 증기발생기 수위제어계통의 고장검출 시스템 설계

본 논문에서는 원저 증기발생기 수위제어계통을 위한 고장검출 시스템을 설계한다. 이를 위하여 증기발생기 수위제어계통의 비선형 동적방정식을 미지의 매개변수를 갖는 T-S 퍼지시스템으로 모델링하고 좌 소인수 분해를 이용하여 오차발생기를 설계한다. 고장검출의 성능을 향상시키기 위하여 고장검출 필터의 설계법을 제안한다. 제시한 방법의 효용성을 컴퓨터 모의실험을 통하여 입증한다. This paper deals with a fault detection system design for nuclear steam generator water level control system. We expressed the nonlinear properties of the steam generator level system as a T-S fuzzy system with time varying uncertain parameters. We design a residual generator using a left coprime factorization of the T-S fuzzy model and a fault detection filter in order to improve the fault detection performance. We demonstrate the efficiency of the suggested design method via many computer simulations.

An Application of Sliding Mode Controller to Nonminimum-Phase Nuclear Steam Generator Water Level Control

The difficulties in designing an effective water level controller for the nuclear steam generator arise from highly nonlinear and nonminimum-phase plant characteristics as well as nonnegative input constraint. In this paper, a modified sliding mode controller with gain scheduling is proposed for nuclear steam generator water level control. A conventional proportional-integral with feed-forward controller is also developed, and the performance of two controllers is compared in the low power range. The modified sliding mode controller shows improvements in the overshoot, undershoot, and settling time.

00/00182 A gain-scheduled [formula omitted] control to nuclear steam generator water level

00/00182 A gain-scheduled [formula omitted] control to nuclear steam generator water level

A gain-scheduled L2 control to nuclear steam generator water level

This paper is concerned with the design of a gain-scheduled controller with guaranteed L2 performance for the water level control of a nuclear steam generator which has parameter varying dynamics. The proposed controller guarantees both stability and a prescribed L2 performance in the entire operating region. The systematical design method for the controller which is automatically adjusted along the reactor power, in terms of Linear Matrix Inequalities (LMIs), is shown. The main benefit of this method is to avoid most of difficulties such as gain-interpolation or griding technique in a classical gain scheduling control. The computer simulation demonstrates the effectiveness of the proposed controller in full operating range and its superiority to conventional PID controllers. ©

Design of a genetic fuzzy controller for the nuclear steam generator water level control

The nuclear steam generator is a nonminimum-phase system, which is caused by the swell and shrink effects. Since its inverse system has unstable dynamics, it is difficult to train the fuzzy controller via the conventional backpropagation of the system output errors. In this paper, a genetic algorithm is applied for the simultaneous design of membership functions and rule sets for a fuzzy control method for a steam generator water level. The genetic fuzzy controller for the steam generator is a fuzzy logic controller which is tuned offline by the genetic algorithm using the water level, feedwater flowrate, and steam flowrate signals of the steam generator. The symmetric Gaussian membership functions based on the flowrate and water level errors are applied. The proposed genetic fuzzy controller has a generalized and simplified rule base. The same genetic algorithm that is used to optimize the genetic fuzzy controller tunes a conventional proportional-integral (P-I) controller, and the performance of two controllers is compared. The genetic fuzzy controller shows good response that its swell and shrink phenomena are smaller and its response is faster than those of a well-tuned P-I controller are.

A fuzzy controller based on self-tuning rules for the nuclear steam generator water level

It was demonstrated that the fuzzy control method could be applied successfully to control and regulate the nuclear steam generator water level through previous works. However, this method has some limitations from the fact that its performance largely depends on the tuning method and how to settle the rule base. In this work, a fuzzy control algorithm based on self-tuning rules is investigated to find the optimal tuning point and to generate the control rule automatically. It adopts an on-line iterative method and the objective error function which contains the variation errors of all time-steps. The triangular membership functions based on the mass flow rate and water level errors are applied. And also, a forgetting factor is used to account for an exponential decay of the past data in tracking the slow drift in system parameters. Thus it controls the steam generator water level from low power to full power with a little transients. This control algorithm is validated by computer simulations.