Study On Pumping Unit Variable Frequency Adaptive System Based On PLC

With the world advocate low carbon, energy saving, environmental protection and sustainable development of the grand blueprint, in the field of heating system technology development, central heating has gradually become the dominant trend in the field of national heating development. This paper is based on Northeast heat exchanger station reconstruction project, the original decentralized heating converted into heat and power plant of central heating station.The design is in Northeast China transformation of the old city heat exchanger station using centralized heating system as the background, from factors of energy saving and environmental protection and sustainable development considerations, to ensure the heating quality of the user as the goal, the design of heat exchange station intelligent control energy-saving system. The system is divided into two parts: a part of Profibus-DP Field bus to realize local monitoring; another part is to realize network remote monitoring center by GPRS wireless network, coordination to complete the heating system requirements. The system includes three parts in the control process: two water supply temperature control valve control, loop system of variable temperature difference control, water supply system of frequency conversion constant pressure control. And in the local control station and remote control center PC using configuration software to realize and control mainly includes the system parameters of the data acquisition and storage, data record, data printing, system fault alarm. Transfer station control system in secondary water supply temperature control on controller design is the key point, this paper developed a secondary water supply temperature control scheme, in analysis of traditional secondary water temperature preset value method shortcomings, it is proposed to use fuzzy controller to obtain from the default value of the control strategy, considering the heat exchange station object of the nonlinear and variable parameter of controlled characteristics, fuzzy parameter self-tuning PID controller to replace the traditional PID controller to achieve dynamic tracking of secondary water temperature. And in the Simulink software simulation, simulation results show that the cascade control scheme with fast response, no overshoot and other advantages, the system is stable and reliable, to achieve the best operating results.The design of intelligent control system for substation effectively reduce the design costs, save resources, improve the use value of the heat exchange station. The control strategy used in this paper is also applicable to the industrial control fields, such as pumping unit, smart grid, smart home and so on.