Identification and dynamic inversion-based control of a pressurizer at the Paks NPP

The paper presents the design of a pressure controlling tank located in the primary circuit of a Nuclear Power Plant. All steps from modeling through control design to implementation are detailed. Based on first engineering principles a second-order Wiener model is formulated and its unknown parameters are identified. The control design is based on a dynamic inversion method. The performance of the designed closed-loop system is tuned by an error feedback. The implemented controller is of a distributed structure including measurement and control PLCs, a continuous power controller and a special supervisor module. The nominal stability of the controller in the networked environment is analyzed by using the maximum allowable transmit interval. The hardware and software design and implementation obey the safety-critical requirements imposed by the special nature of the plant.