Development And Study Of High-temperature Multiphase-flow Wind Tennel Automatic Control System Based On PLC-SCADA

This paper is based on the High-Temperature Multiphase-flow Wind Tunnel project, which is one of the state key laboratory construction projects of Thermal Engineering, Zhejiang University. According to the characteristic of low-speed wind tunnel experiment system and learning from the advanced control technology and the successful experience, we use PLC-SCADA system to realize automatic controlling. The system is made up of new-generation PLC and SCADA which suits middle and small control domains. In this paper, the main task depends on the research and development of PLC-SCADA system.The High-Temperature Multiphase-flow Wind Tunnel is a big inertia and strong coupling system, and conventional PID control system is unable to satisfy it. Based on the research of PID control principle, digital PID control and adaptive PID control system, self-optimizing control algorithm was introduced in to realize the control of wind speed, temperature, particle concentration and the wind tunnel negative pressure.PLC-SCADA system is composed of three levels: the field control level, the process supervisory control level and the experiment manage level. The automatic control system design for the three levels: the field control level is consisted of programmable controller and auto-measure instrument; the process supervisory control level is composed of Industrial Personal Computer (IPC) and configuration software which is called the OP station; the experiment manage level comprises of Personal Computer (PC), IIS server and manage software called Server&Administrator. Functional design of the system includes Automatic monitor design, Automatic control design and Web service design, to realize the three levels subsystems of PLC-SCADA: Field PLC control system, OP station process supervisory control system and manage service programme.According to the design, we select Windows 2000 operating system as developing platform which is applicated maturely, stablely, reliably and has powerful network function, use SIMATIC STEP7 V5.1 The PLC field control program to carry out, and use the industrial automation common software KingView 6.51 to develop the OP station process supervisory program. On the foundation of the KingView 6.51 network service function, the combination of ASP, Access2003 and IIS was adopted to carry out the development of the experiment manages service program.The PLC-SCADA automatic control system of High-Temperature Multiphase-flow Wind Tunnel has stable automatic control function, perfect man-machine operation interface, powerful data-handling capacity, meanwhile it has the local area network long-distance management and service function. So it has completely realized the wind tunnel experiment automatic control.