Linear active disturbance rejection control for pressurized water reactor power based on partial feedback linearization

Traditional input–output feedback linearization requires full knowledge of system dynamics and assumes no disturbance at the input channel and no system’s uncertainties. In this paper, a model-free active input–output feedback linearization technique based on an improved active disturbance rejection control paradigm is proposed to design feedback linearization control law for a generalized nonlinear system with a known relative degree. The linearization control law is composed of a scaled generalized disturbance estimated by an improved nonlinear extended state observer with saturation-like behavior and the nominal control signal produced by an improved nonlinear state error feedback. The proposed active input–output feedback linearization cancels in real-time fashion the generalized disturbances which represent all the unwanted dynamics, exogenous disturbances, and system uncertainties and transforms the system into a chain of integrators up to the relative degree of the system, which is the only information required about the nonlinear system. Stability analysis has been conducted based on the Lyapunov functions and revealed the convergence of the improved nonlinear extended state observer and the asymptotic stability of the closed-loop system. Verification of the outcomes has been achieved by applying the proposed active input–output feedback linearization technique on the single-link flexible joint manipulator. The simulations results validated the effectiveness of the proposed active input–output feedback linearization tool based on improved active disturbance rejection control as compared to the conventional active disturbance rejection control–based active input–output feedback linearization and the traditional input–output feedback linearization techniques.

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Linear Active Disturbance Rejection Control for Fast Nuclear Reactor

Volume 1: Operations and Maintenance, Engineering, Modifications, Life Extension, Life Cycle and Balance of Plant; I&C, Digital Controls, and Influence of Human Factors ◽

10.1115/icone25-66768 ◽

2017 ◽

Author(s):

Liu Feng-ming ◽

Shen Cong ◽

Zhang Hua-xia ◽

Zhou Shi-liang ◽

Liu Yu-yan ◽

...

Keyword(s):

Disturbance Rejection ◽

Nuclear Power ◽

Power Reactor ◽

Power Level ◽

Reactor Core ◽

Reactor Power ◽

Active Disturbance Rejection Control ◽

Nuclear Power Reactor ◽

Active Disturbance Rejection ◽

Disturbance Rejection Control

Since dynamics of a fast nuclear power reactor is quite nonlinear, uncertain and time-varying. Moreover, the reactor period depends on the neutron lifetime and it has a crucial importance in reactor power so it is necessary to have a control system for the reactor power. A reliable method for power-level control named linear active disturbance rejection control (LADRC) based on power-level for a fast nuclear power reactor is presented in this paper. The reactor core is simulated based on the point kinetics equations and one delayed neutron group, fast reactor reactivity equation which is very different from thermal reactors and thermal-hydraulics model of the reactor core. This model is completed by calculating initial value of related parameters and system debugging. Finally, it is prove that this model is reasonable and can be used for controlling. The structure of LADRC is very simple and the Bandwidth-Parameterization based controller tuning is easy. It consists of a PD controller and an extended state observer (ESO). Two LADRC systems are designed for power control with model information and without model information respectively. Simulation results show that both the designed controllers have satisfactory performance over the wide range of reactor operating conditions, while LADRC with model information has faster response, less overshoot, better disturbance rejection ability, greater robustness.

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