基于PLC的中央空调水泵变频调速控制系统设计

基于PLC的中央空调水泵变频调速控制系统设计Central Air conditioning's Water Pump Frequency Control ofMotor Speed Control System Design Based on PLCAbstractWith the continuous progress in science and technology and improvement of thequality of life,the central air conditioning has gradually entered the people's vision,which has become an important part of people's life.At the same time,the energy itconsumes also caused concern in the community.The energy saving problem ofcentral air-conditioning has become the key problem that people expect to solve.Central air-conditioning system which is based on variable frequency technologyin a certain extent greatly can reduce energy consumption.,It adopts speed-adjustedsystem through frequency conversion which on the one hand brings the success ofthe motor soft start,and on the other hand which also reduce the vibration andabrasion and prolongs the life of the motor.Central air-conditioning pump variablefrequency technology is an effective way to save energy.Moreover,it has get thesupport of national policy and it has been on behalf of the future direction ofenergy-saving air-conditioning industry technical.This graduation design is mainly designed by Siemens S7-200 cpu226 which isused to control element for the research and design of central air conditioning waterpump frequency control of motor speed control system.The design in this thesis willexplains the principle,model selection and parameter design of the converter and theprogrammable controller.The design will focus on the completion of PLC hardwarecircuit diagram and program design.The economy of the central air conditioning water pump frequency conversionspeed control system is very considerable which will have a very good prospect andopen market.Key Words:Central Air ConditioningVariable Frequency Speed ControlProgrammable Controller