Power-pressure coordinated control of modular high temperature gas-cooled reactors

Abstract

Modular high temperature gas cooled reactor (mHTGR) adopts helium as coolant and graphite as both the moderator and structural material, whose fuel element is built by embedding thousands of TRISO coated particles into a graphite matrix. Since helium is an ideal gas, the dynamics of reactor coolant temperature is tightly coupled with that of primary pressure. To further improve the operation performance, it is meaningful to develop the coordinated control of power-level and primary pressure for mHTGRs. In this paper, a passivity-based power-pressure coordinated control is proposed for mHTGRs, and the sufficient condition for globally asymptotic closed-loop stability is given. This newly-built power-pressure coordinated control law is applied to the mHTGR of six-modular high temperature gas-cooled reactor plant HTR-PM600, and simulation results in the case of power ramping decrease and increase as well as performance comparison not only verify the theoretical result about closed-loop stability but also illustrate the influence of control parameters as well as the stronger performance relative to the classical proportional integral/differential (PI/D) controller.