Performance Analysis and Optimization of Fang Jiashan DCS Level 2 System

Abstract

This paper is based on the experience of Fang Jiashan DCS level 2 system optimization project. Level 2 system is the essential part in the whole DCS system as it is responsible for monitoring and controlling the plant operation. Its performance affects the stability and economic efficiency of the plant operation directly. This paper briefly describes the architecture of Fang Jiashan Nuclear Power DCS level 2 system and the way of signal exchanging among the different levels of DCS. It also describes how the signal scanning and processing mechanism affect level 2 system performance, and demonstrates in detail why there were signals delayed during the major test-like disconnection from grid test at the 100 % power level. This paper also proposes optimization methods to enhance the performance for the level 2 system in multiple aspects including hardware upgrade, signal scan rate optimization, internal calculation process mechanism improvement, system task scheduling mechanism improvement and system architecture optimization. The methods for performance optimization discussed in this paper have been applied to DCS level 2 system updating project of Fang Jiashan NPP and Fuqing NPP 1&2 successfully, which have been proved feasible and effective, the schemes are valuable for new plant DCS design and construction or for old plant DCS refurbishment in certain aspects.