Smith预估补偿控制在燃煤电厂烟气脱硝控制系统的应用

Application of Smith Predictor Control in Coal-fired Power Plant Flue Gas Denitrification Control System

摘要:

电站锅炉的烟气脱硝过程同其他电站热工过程一样存在一定迟延性和惯性；根据目前烟气脱硝系统运行情况,总结分析了氮氧化物(NOX)排放控制过程的特点、影响因素以及控制系统；为解决锅炉运行过程中系统呈现出的大迟延和大惯性问题对整个烟气脱硝控制品质产生的影响,以及实现系统的稳定性和快速性,在原有的串级回路系统中,加入了Smith预估补偿控制器提前预估系统的动态特性并对其进行补偿；根据烟气脱硝系统对象的传递函数,设计了Smith预估补偿控制系统,采用Matlab中的Simulink对控制系统的对象和改进前后的控制系统响应曲线进行仿真分析,可以看出改进后系统动态品质变好,系统的快速性和稳定性也明显提高。

Abstract:

Power plant boiler flue gas denitrification process exist certain delay and inertia like other power plant thermal process. Based on the current flue gas denitrification system operation,analyzed the nitrogen oxide (NOX) emissions control process characteristics,influencing factors and control system. In order to solve the certain delay and inertia problem for the entire flue gas denitrification control affect the quality of produce during boiler operation,and the realization of the system stability and fast,added ahead of Smith Predictor Controller estimate the dynamic characteristics of the system and its compensation in the original cascade loop system. According to the transfer function of flue gas denitrification system objects,design of Smith Predictor Control System,analysis the control system objects and the response before and after improved control system by Simulink of Matlab,as can be seen dynamic quality better of the improved system,speed and stability of the system has improved markedly.