A nuclear reactor is a complex, nonlinear, and time-varying system. External disturbances and uncertainty due to neutronic and thermal-hydraulics parameters variation contribute to reactor control challenges and safe operations. Thus, this paper presents a hybrid control system for a nuclear reactor core power control in the presence of a matched disturbance and uncertainties. The hybrid controller combines Linear Quadratic Gaussian/Loop Transfer Recovery (LQG/LTR) optimal control and a nonlinear Integral sliding mode control (ISMC). The nonlinear system of the reactor, which is based on point kinetics equations with three delayed neutron group is linearized to design the LQG/LTR. The Lyapunov theory is used to prove the finite-time convergence of the Integral sliding mode control. Furthermore, a comparative analysis of the hybrid control scheme, LQG/LTR, PID, and an ISMC is conducted with the nonlinear model. Simulation experiments reveal that the closed-loop hybrid control system is stable and achieves the best performance specifications in the presence of external disturbance and uncertainties.

核反应堆是一个复杂的，非线性的且时变的系统。由于中子和热工液压参数变化而引起的外部干扰和不确定性加剧了反应堆控制挑战和安全运行。因此，本文提出了在存在匹配干扰和不确定性的情况下用于核反应堆堆芯功率控制的混合控制系统。混合控制器结合了线性二次高斯/环路转移恢复（LQG / LTR）最优控制和非线性积分滑模控制（ISMC）。基于具有三个中子延迟群的点动力学方程，将反应堆的非线性系统线性化，以设计LQG / LTR。利用李雅普诺夫理论证明了积分滑模控制的有限时间收敛性。此外，对混合控制方案进行了比较分析，使用非线性模型进行LQG / LTR，PID和ISMC。仿真实验表明，在存在外部干扰和不确定性的情况下，闭环混合控制系统是稳定的，并能达到最佳性能指标。