Event-Driven-Based Water Level Control for Nuclear Steam Generators

Safety is a critical issue in nuclear power exploitation and utilization. With respect to a pressurized water reactor in a nuclear power unit, a steam generator is a crucial device, whose water level control performance directly affects the safety and stability of the pressurized water reactor. In this paper, based on an event-driven control methodology, a novel steam-generator water level control strategy is proposed to lower the computing load of the control system and extend the service life of actuators. The theoretic stability analysis for a closed-loop system with an event detector is adequately expressed. The two-degree-of-freedom internal-model-control feedback controller and the dynamic feedforward controller, both of which are triggered by the same event detection logic, are designed to guarantee local performance. In addition, a gain-scheduling measure is adopted to combine local controllers to ensure the overall performance under all power levels. Comparing case studies shows that the proposed control strategy exhibits good capability to manage the utilization of a process control unit and the control action, with no deterioration in the control performance.