The Distributed System For Power Factor Compensation Based On RS485Bus

In recent years,with the continuous development of society,power quality requirementsto industrial users are becoming higher.In order to meet requirements,improving quality ofpower supply and stability of power supply process and reducing loss of power supplyprocess need to provide a large number of reactive power compensation device.Therefore,it is important and necessary to study reactive power compensation device.Based on thissituation,design a set of reactive power compensation device.The accurate calculation of power factor is crucial to compensation device.Because ofdirect current component and high harmonic in power grid,using fast fourier algorithm isalmost not affected.High measuring accuracy and fast computing speed can adapt torequirements of fast track dynamic compensation device.Write program and analysis everysimulation module,verify it through comparison of data under MATLAB simulation.Firstly,it describes principle of reactive power compensation and working principle ofdistributed compensation system,then displays master-slave machine connection mode andworking principle.The central processor is STC12C5A60S2microcomputer controlunit.which completes data processing,a serial port communication, display and otherfunctions.Peripheral circuit contains voltage and current sampling circuit,output drivingcircuit,man-machine interface display circuit,serial interface and power supplymodule,etc.It provides hardware platform for realization of software.Software design usesmodular programming method,which makes program structure clear,easy to maintain andextend function,reduce probability of error.Software part introduces the program designflow of every module in detail.Based on this,compensation device uses a certain percentage of capacitor banksaccording to optimal filing principle.Controller detects each capacitor network address andsize.According to need of compensate reactive power,it chooses a set of compensationcapacity which is closest but less than compensation mode in all groups of capacitor,tocompensate.This realizes intelligent.Finally,prototype works well and is able to accurately monitor all kinds of electric parameters,and can cast and cut capacitance according to the corresponding command,theresults meet the design requirements, the effect of the reactive power compensation inpower grid can be achieved.