Design of control systems for nuclear plant processes: A hardware-in-The-loop simulation approach

Nuclear domain can be considered as a challenging field of application for control systems and the related electronic technology. A prototypal version for controllers is often mandatory for a preventive test and performance evaluation. Control engineers often develop very accurate model of a specific process with very sophisticated control laws using a simulation environment. Even if simulations are fundamental for studying the process and selecting the best control technique, this theoretical effort can be a critical issue for the subsequent hardware implementation of the controller on real electronic devices, leading to a difficult conversion from software to hardware. In this context, the so called Hardware-In-the-Loop HIL simulations is a valid help, allowing a plant process to be simulated in a real time environment and the control unit to be realized on a real component and included in the whole simulation. In this work, HIL simulations are presented and compared to fully software simulations in case of the prototype realization of a pressure controller for a Pressurized Water Reactor PWR. Digital hardware technology is here introduced from the scratch into the project, and the physical implementation of the control unit is taken into account from the beginning, with a significant improvement of the accuracy of the controller in the real process. The control unit is based on a Field-Progammable-Gate-Array (FPGA), a widespread device for real-time control. FPGAs let designers to program a wide number of digital gates in their functionalities with a intrinsic determinism. In addition, processes can be managed in a real parallelism and without the resource sharing as in a CPU operating system. Results demonstrate the effectiveness of such an approach.Copyright © 2014 by ASME