基于前馈-反馈控制的天然气分输站场控制及前馈控制率自适应方法

Feedforward-backward Control based Natural Gas Distribution Site Control and the Feedforward Control Law Updating Method

摘要:

天然气分输站场控制系统直接影响天然气配输质量及系统的安全可靠运行,站控系统调节阀控制是关键。目前我国天然气分输站场调节阀采用的国内厂家配置的PLC控制系统大多采用三选一式的PID控制策略,在峰谷分输、大范围调节以及上游流量压力存在较大波动的情况下普遍存在控制稳定性欠佳、调节周期长的弊端。为了改进控制效果,本文在深入分析造成控制效果欠佳原因的基础上,提出了基于前馈-反馈控制的控制策略,并基于此前馈-反馈控制策略提出了前馈控制率自适应调整方法以适应实际过程中调节阀动态特性变化额情况。在Stoner Pipeline Simulator软件仿真对象了进行了初步验证,仿真结果表明施加了前馈控制作用后控制稳定性和调节时间有显著优化,本方法具备在现场推广应用的前景。

Abstract:

Due the control system for the natural gas distribution site has a direct impact on the system safety and normal operation, the valve control method is of vital importance. For now, the common control strategy widely used in current field sites is the PID based control strategy using PLC controllers. For this control strategy, the low control precision and long tuning period is the major drawback, especially in the case of peak time and large disturbance in upstream and downstream flowrate and pressure. To improve the control effect, we analyze the root cause of the poor control performance and propose a feedforward and backward based control strategy. Moreover, to improve the robustness of the control strategy, an updating strategy for the feedforward control law is proposed to disperse the influence by the dynamic variation in control valve. Finally, a case study and simulation comparison is given based on the Stoner Pipeline Simulator platform. The simulation result shows that the proposed control strategy outperforms the traditional strategy in both control stability and stabilizing time. The proposed control strategy has a promising field application future.