On the Feasibility of a RGA-Based Decoupling Control in the Reactor-Follow-Turbine Operation of a PWR

Closed-loop control of the reactor-follow-turbine operation is attempted in this work. The reactor power is intended to follow the turbine load demand, whereas the coolant average temperature is to be maintained constant for reasons of design safety. To this effect, a standardized pressurized water reactor model is adopted wherein the reactor external reactivity and the feedwater mass flux are deemed the manipulated control signals. Offline system identification is carried out on the model input/output (I/O) terminals to extract first order plus time delay models thereof. A further relative gain array analysis is conducted to determine the most tightly coupled I/O channels. A proportional integral controller is thereafter designed for each channel, making use of an analytical gain/phase margin tuning mechanism. The results for different output tracking scenarios confirm a feasible and quite satisfactory closed-loop control practice.