Intelligent Control Of Compressed Air Energy System's Development

As an important power source, compressed air is widely used in commercial run and scientific experiments, such as various pneumatic machinery, pneumatic tools, air-actuated jaw, automatic detection, automation, spray paint, pneumatic experiment and so on. It is an indispensable secondary energy sources in industrial production. Along with the rapid development of manufacturing industry and the slathering of automation machine, compressed air increasingly widen its range of application. At present, however, compressed air system mainly adopts relay or PLC control. The intelligent level of this kind of control mode is not high, the output pressure is unstable and the energy dissipation is serious. So technicians are trying to solve the problems that how to control the pressure of compressed air in a certain range in order to satisfy the demand of industrial devices and how to update the technology of the old control systems.According to the problems mentioned above, by using the design concept of frequency conversion control and energy saving, an intelligent control system of compressed air system with the fuzzy control function was researched and developed, which includes three parts such as control strategy, hardware design and software design.In order to solve the existing problems of large lag and poor stability of air supply system for compressor, air supply system with constant pressure for compressor based on fuzzy-PID controller was designed. The fuzzy-PID controller of the system combined traditional PID control with fuzzy control which can adjust parameters of the whole system automatically and finally realize air supply with constant pressure. The pressure switchers of the equipment exports will transform the practical pressure signal into the standard electrical signal which will be put into the PID regulator, and then be compared with the hypothesis signal, by processing proportional, integral, differential computation, we will obtain the optimizing control parameters to control the output of frequency conversion voltmeters, then control the air compressors'operation.In the aspect of hardware design, the system is divided into three layers:equipment, data collection, management. The design idea is taking the computer as control core which was outfitted with necessary PLC,A/D,D/A modules and configuration software. So this system is an intelligent and real-time multi-parameter control system. This system used the PLC to control the system's starting and shutting.This system use SIMATIC WinCC Explorer, PC Access, STEP 7 Micro WIN to develop software of compressed air system, and C++, LAD, FDB language to develop the programs. The software realized the expert control, parameter setting, system self-check, manual control, alarm processing, data management and system management function.The actual running result showed that the system can do optimal control according to the changes of air supply devices and environment, which has improved the system's reliability, stability, dynamic respond speed and energy-saving effect, has achieved the expected design requirements.