Output Feedback Dissipation Control for the Power-Level of Modular High-Temperature Gas-Cooled Reactors

Abstract

Because of its strong inherent safety features and the high outlet temperature, the modular high temperature gas-cooled nuclear reactor (MHTGR) is the chosen technology for a new generation of nuclear power plants. Such power plants are being considered for industrial applications with a wide range of power levels, thus power-level regulation is very important for their efficient and stable operation. Exploiting the large scale asymptotic closed-loop stability provided by nonlinear controllers, a nonlinear power-level regulator is presented in this paper that is based upon both the techniques of feedback dissipation and well-established backstepping. The virtue of this control strategy, i.e., the ability of globally asymptotic stabilization, is that it takes advantage of the inherent zero-state detectability property of the MHTGR dynamics. Moreover, this newly built power-level regulator is also robust towards modeling uncertainty in the control rod dynamics. If modeling uncertainty of the control rod dynamics is small enough to be omitted, then this control law can be simplified to a classical proportional feedback controller. The comparison of the control performance between the newly-built power controller and the simplified controller is also given through numerical study and theoretical analysis.

Dynamic Output Feedback Power-Level Control for the MHTGR Based On Iterative Damping Assignment

“…The L 2 disturbance attenuation performance of this newly-built control law is guaranteed by choosing the values of both parameters ε and σ to be small enough. With comparison to the power-level controller presented in [29], the transition periods of both the fuel and coolant temperatures caused by the newly-built controller in this paper is much smaller than those corresponding to the controller in [29]. This is just an instance for the fact that dynamic output feedback control is stronger than static output feedback control, and this is also the key improvement of the work in this paper relative to that in [29].…”

“…The schematic view of the dynamic model of the NSSS for numerical simulation is shown in Figure 2. Furthermore, the model of the steam turbine and that of the electrical generator are also included in the simulation code [29]. The numerical simulation of this paper was done by the use of this simulation code.…”

Nonlinear Power-Level Control of the MHTGR Only with the Feedback Loop of Helium Temperature

“…In case B, the performance of dynamic output feedback power-level control strategy (59) is compared with both the feedback dissipation based power-level control (FDBC) presented in [13] and the simple proportional feedback control taking the form as:…”

“…The structures of the feedback loops of the dynamic output feedback power-level control strategies presented in [14] and this paper are shown in Figure 3. Figure 3(a) shows the feedback loop in [14], and Figure 3(b) shows the feedback loop in this paper, which means that the control strategy given in this paper needs less measurement information than those in [13] and [14] need. …”

“…However, there are some promising power-level regulators. A feedback dissipation based power-level control law (FDBC) was developed, which has the virtues of being globally asymptotically stabilizing and easy implementation [13]. In order to improve the control performance, a nonlinear state-feedback power-level control based upon the technique of iterative damping assignment (IDA-PLC) was then proposed [14].…”