适用于DCS改造的轻量化协调模型框架OA

To address the tough problem of insufficient time for coordinated control logic verification during Distributed Control System(DCS)retrofits of thermal power units,this paper proposes a lightweight simulation framework for coordinated control systems and applies it in practical engineering projects.At the core of the framework lies a simplified model,which simplifies the complex coordinated system of thermal power units into a two-input two-output system.Its input variables are total coal feed rate and turbine valve opening,while output variables consist of main steam pressure and unit power.The model retains the critical dynamic characteristics of boiler-turbine coordination and can be easily implemented with DCS function blocks.A convenient parameter tuning method and simulation switching initialization circuit are developed,and simplified simulation models of feedwater,total air flow,oxygen content,furnace pressure and other process objects are integrated to establish a complete coordinated control simulation system.The framework is put into practical test in the DCS retrofit project of a 660 MW supercritical unit.Test results demonstrate that the lightweight simulation framework can effectively assist the verification of key control logics including unit variable load operation,auxiliary equipment RUNBACK and BTU correction.It drastically cuts down on-site commissioning workload,and improves engineering commissioning quality as well as unit operational safety.