A multi-point kinetics based MIMO-PI control of power in PWR reactors

Nodal dynamic modeling of a PWR reactor core has been carried out to provide a reliable basis for multivariable control of the load following operation. A Two- Input/ Two Output (TITO) plant is developed accordingly. The overall output power and the pertained axial offset are regulated concurrently within a multivariable PI control framework. To this end the analogous problem of power regulation in the upper and lower half cores is addressed. Control rod movement and boric acid concentration are set as the control inputs. Davison tuning strategy which takes into account the steady state gain matrix of the plant has been employed as an easily implementable approach to provide the intended PI parameters. The overall control strategy shows quite satisfactory tracking performance of the desired output power and flux tilt profiles while a safe level of the controlling signals is obtained.