Robust Fault Detection for a Nuclear Reactor System: A Feasibility Study

Abstract

Abstract This paper describes a feasibility study of robust model-based method in the fault detection of a nuclear reactor. The fault detection scheme is designed to be insensitive to disturbances, whilst being highly sensitive to faults. Firstly, the paper describes a robust fault detection approach based on eigenstructure assignment technique. By assigning the left eigenvectors of the observer orthogonal to the disturbance, robust (disturbance decoupling) fault detection is achievable. Then, the approach has been applied to an 11th order model of a nuclear reactor system. A reduced order model is used to approximate this system and modelling errors are considered as disturbances acting upon the reduced order model contained in the observer. A particularly novel feature of the work is the use of a new method for estimating the disturbance direction(s). The robust fault detection scheme design uses this direction as that of the direction of unknown input acting on a reduced order model. Simulation results show that the scheme can detect soft or incipient faults efficiently.