基于LabVIEW的离心泵闭环恒压控制特性试验

摘要

利用虚拟仪器构建了基于变频器内置PID控制器的离心泵恒压闭环控制测试系统,将泵系统出口端改造成3个球阀的出口形式,能定量快速地改变工况,实现了近似阶跃的输入扰动.编写LabVIEW测试程序对离心泵恒压控制特性进行了试验研究,得出了离心泵恒压控制系统给定压力的设置范围,通过比较恒参数PID控制在不同工况变化下的控制性能,发现恒参数PID控制在工况变化较快和较大时,控制性能不理想；通过分析同一工况下恒参数PID和变参数PID的控制性能,得出变参数PID控制能更好地适应离心泵恒压控制系统.%In order to investigate the constant pressure control characteristics of centrifugal pump, a testing system on constant pressure closed-loop control of centrifugal pump water-supply system, which was based on internal PID controller of frequency converter was set up by using the virtual instrument. An innovative form of the outlet of the pump system composed of three ball valves was remodeled. It could change working condition quantitatively and rapidly. The outlet could create similar step disturbance. A LabVIEW test program was compiled to do research on control characteristics of constant pressure centrifugal pump system. The set range of the given pressure of the constant pressure control system was concluded. Contrasting the control characteristics of the fixed parameter PID regulator under different working conditions, it is showed that the control characteristics of the fixed parameter PID regulator are not good under the working conditions that changes quickly and extensively. Analyzing the control characteristics of the fixed parameter PID regulator and the variable parameter PID regulator under the same working condition, it is discovered that the variable parameter PID regulator is more applicable for the constant pressure control system.