Central Air Conditioning SCADA System And Implementation Of Things On

It is well-known that energy conservation has became a strategic approaching to thelow-carbon economy in the future development of our country,and meanwhile,the centralair-conditioning system has become one of the most important energy consumption in citybuildings nowdays,thus the study of a energy-efficient and Intelligent central air-conditioningsystem is going to be of ever great significance in the national promotion of energy savingeconomy.Based on the structure of Supervisory Control And Data Acquisition （SCADA）system,this thesis has designed a new central air-conditioning SCADA system.The new systemwhich takes the advantage of the Internet of Things, structured in three mechanisms layers of datagathering, network communicating and application, can bring many benefits for the controlling ofcentral air-conditioning equipments,such as intelligence,energy-saving and remotemanagement.Focused on the structural features of new central air-conditioning system as well asthe functionality of all system modules, the thesis consists of the following parts:1、After studying the three-layer architecture and core technologies of the Internet of Things,based on the structural characteristics of traditional SCADA system,the author put forward thethree-layer architecture of the new central air-conditioning SCADA system with its overallimplementation, and then discussed the composition of new system, as well as the functionalityand implementation of key system modules in detail.2、Then,the author analyzed the network structure and communication method of thenetwork layer in the new system,and further more, by using Modbus/TCP proctol and gatewaytechnology,proposed a way of interconnection and communication among equipments withmultiply interface,including fieldbus,Ethernet and ZigBee,which provides a variety of networkingresolution for practical applications.3、The hardware and software design of the thermostat node,which is the core equipment indata gathering layer of the new system,is put forward in the thesis.A low-cost and low-powerSTM32F103VET is chosed as the the main controller on thermostat node.Based on the embeddedoperating system,the node can work with both Modbus RTU mode and Modbus TCP mode byimproting the TCP/IP protocol stack LwIP and Modbus protocol stack FreeModbus.What’smore,with the introduction of Web services and IAP technology,the new thermostat node canupdate its firmware remotely and automaticly on system network,whcih will bring benefits forsystem maintenance and muti-nodes management.4、Also the hardware and software implementation of a multi-protocol gateway is proposedin the thesis,which is the core equipment in network layer of the new system.Standing on thephilosophy of modular,interchangeable and scalable,the hardware design mainly includes the minimum system of controller STM32,circuit implementation of various communication modules,and so on.The software design includes both the implementaion of a Modbus TCP service taskand a ZigBee services task,which can fulfill the data frame conversion among different physicallinks,and consequently fulfill the communication between different network layer equipmentsand Ethernet user.5、At last,based on the configuration software ForceControl,a hypervisor software is built forsystem monitoring on host computer with a remote GUI interface.Also by connceting the I/Odevices to a real-time database,a Web server with B/S structure is built for systemAdministrator,remote users can control the terminal devices promptly and intelligently justthrough a browser.The new system in this thesis has been successfully used in the central air-conditioningsystem of a hospital in Shaoxing City,initialized by an air-conditioning technology companynamed Zhejiang Weimin.The practical test results shows that the air-conditioning equipmentsdescribed in the thesis work stable and efficient,and the performance of the system is in line withexpectations.Above all,the new networked SCADA system,with its implementation techniquesdiscussed in this thesis can adapt to other control fields,and as well can provide many new ideasand methods to achieve practical engineering applications.