The Nucleus 52, No. 1 (2015) 1-8 www.thenucleuspak.org.pk 1 The Nucleus I SS N0 0 2 9 - 5 6 9 8 ( Pr i nt )I SS N2 3 0 6 - 6 5 3 9 ( On l i ne )Paki stanTheNucleusElectricalEnergySavingandManagementInitiatives:ACaseStudyofUniversityLibraries in KPK, Pakistan S.Z. Hassan1*, T. Kamal1, S.R. Hassnain2, H. Ali1 and A. Saleem3 1Electrical Department, COMSATS Institute of Information Technology, Abbottabad Campus, Abbottabad, Pakistan 2Electronics Department, University of Engineering & Technology, Peshawar, Abbottabad Campus, Pakistan 3Oil and Gas Development Company Limited, Islamabad, Pakistan A R T I C L EI N F O Article history : Received: 08 May, 2014 Revised: 09 February 2015 Accepted: 12 February 2015 Keywords : Case study University library Energy saving system A B S T R A C T Severalrecentstudiesshowthatasignificantportionoftheelectricalenergyconsumptionin educationalinstitutes,residentialandbusinessbuildingsareduetotheimproperuseofelectrical appliances.Theobjective of this paperis to develop acost effective automated powermanagement systemfortheacademicinstitutionstoreducetheconsumptionofelectricalenergy.Tothisaim,a sensor-based intelligentsystem and decisionmaking algorithmare proposed.As peralgorithm, the system monitors the number of persons, intensity of light, temperature and accordingly controls the behaviorofappliances.ThispaperincludesacasestudyoftwouniversitylibrariesinKPK, Pakistan, namely, University of Engineering and Technology(UET), Peshawar, Abbottabad Campus andHazaraUniversityMansehra.Theanalysisoftheexperimentalresultsconcludesthatthe proposed energy saving system (PESS) is able to provide a significant energy savings. 1.Introduction Itisaknownandrelevantfactthatthefutureprogress andeconomicdevelopmentofacountrydependsuponthe availability of electrical energy. The continuous increase in populationandindustrialdevelopmentrapidlyaccelerate theenergyconsumptionrate.Approximately41%ofthe overallworld-wideenergyconsumptioniscoveredby educationalinstitutes,residentialandbusinessbuildings [1]. The major cause of energy consumption in educational institutesarespaceheating,aircooler,airconditioning, lighting, the use of computers, printers and other electronic appliances [2].Major part of energy consumption is due to theimproperuseofsuchappliances,especiallytheuseof electricalappliancesinstandbymodewhichaccounts10% of the overall energy consumption [3]. According to several studies, thestudents play an important rolein reducing the overallenergyconsumptionineducationalinstitutes. However,thiscanonlyhappenifthestudentsaremade aware of the consequences of consuming too muchenergy. Aneffectivesolutiontothisproblemwouldbean automatedmonitoringenergymanagementsystemin additiontousercooperation.Thispaperexploresthe ongoingeffortsintwohigheruniversitylibrariesfor monitoring and controlling thepower consumption of each appliance that is used by the libraries. The system proposed inthispaperisanetworkofdifferentsensorsanda microcontrollerthatisabletocheckandcontrolthebehaviourofelectricalappliancesinauniversitylibrary inordertominimizetheoverallenergyconsumption withoutaffectingthecomfortlevelofthe users. Thisworkisorganizedasfollows:Section2explains therelatedwork. Section 3 describes thesurvey performed indifferentplaces,whilesection4presentstheproposed work.Section5hoststhehardwaredescription.Section6 providesthesystemoperatingfunctionsindetails.Section 7, 8 and 9contain the results, cost analysis and conclusions, respectively. 2.Related Work Intheliterature,manyapproachesaresuggestedfor saving an electrical energy. In [4], the author developed and implementpowersavingsysteminclassrooms.They focusedonlyonthecontrollingoflightsandfansanddid notconsiderthetotalelectricalappliancesanddevicesin theclassrooms.Adistributedmonitoringsystembasedon ACpowermetersforreducingenergyconsumptionin buildingsisdescribedin[5].ThesameACmeterisalso triedinanotherstudyonenergysavingperformedinthe computersciencedepartment[6].Theaimofthestudyin [6], is to understand how, where, and for whom electricity is utilized.Thesameobjectiveisalsopresentedin[7,8]. Monitoring electrical appliances in buildings is the purpose of[9],wheretheauthorsdescribetheenergyconsumedin variousbuildingsand/orvariousfloorswithinthesame buildinginauniversitycampus.In[10],theauthor discussedhomeautomationsystem,whereheconcludes, thatautomaticenergysavingsystemarebeingpreferred overthemanualsystem.Inthesamefashion,smart - Corresponding author : zulqadar@ciit.net.pk S.Z. Hassan et al. / The Nucleus 52, No. 1 (2015) 1-8 2 meteringforenergyauditisstudiedin[11].Allthe previous papers mainly concentrated on energy monitoring, whilethispaperprovidesanoverviewofpower management of electrical appliances and the rule of modern powerelectronicsconvertersandPIC-microcontrollerto decreasetheenergyconsumption.Theparametersusedin this paper are presented in table 1. Table 1:Nomenclature SymbolDescription Firing angle maxMaximum firing angle =180 ViAC input voltage = 220V TmaxMaximum temperature set point TminMinimum temperature set point VinDC input voltage = 12V ybOutput of ADCWAPDAWater And Power Development Authority Temperature sensor resolution = 10mV/C 3.Survey Toknowaboutthepowerutilization,adetailedsurvey reviewhasbeencompletedintwodifferentacademic institutes. 3.1.Analytical Survey TheacademicinstitutesofNewZealand,Canadaand Americaspentanaverageof$1.10persquarefooton electricalenergy[12].AccordingtotheSurveyreport, university classroombuilding and lightingaccounts31%, whilespaceheatingrecordsfor28%oftotalpoweruse. Thepercentageshowsthattheseplacesarethebesttarget forenergysavings[13].InAsiancountries,suchasIndia, China and Pakistan space cooling is done normally through ceilingfansorairconditioners.Inordertocollectthe statistical data, we measure the energy consumption of each deviceprovidedbyPEPCO(PakistanElectricPower Company) as shown in table 1 [14]. 3.2.Actual Field Survey A random survey is conducted through the working day atdifferenttimes(e.g.studyhours,teabreaksandlunch breaks)intwolibrariesoftwodifferentuniversities.The surveywasfirstconductedattheUETPeshawar, AbbottabadCampus&thanthesurveywasconductedin Hazara University, Mansehra. Table 2:Electrical load Type of ApplianceWatts Tube light (Ordinary Choke)40 Tube Light (Electronic Choke)70 Ceiling Fan70 Table Fan60 GLS Bulb100 3.3.Survey Analysis and Observation The following observations were made from conducting the survey. 1.Boththelibrariesarefullyoccupiedandallelectrical appliances and devices are turned ON. 2.Both the libraries are not fully occupied and all electrical appliances and devices are turned ON. 3.Both the libraries are fully un-occupied and all electrical appliances and devices are turned ON. Thefirstobservationdescribesaverynormalsituation and there were no problems found. The second observation indicatestheoccupancyduringteabreaksandthethird observationprovidesthestatusofapplianceswhennoone ispresentinthelibrary.Since,thesecondandthird observationsconcludedthatthereexistsatremendous possibility to save energy in the libraries.This can be done byusingtheappliancesaspertheauthenticrequirementofthe students. 4.Proposed Work Aninnovativeapproachisfollowedtosavethepower consumptionofelectricalappliancesnormallyusedinthe librarysuchasceilingfansandlightingbulbs.Forthis,a proper power management system (PMS) is needed. PMS is designed to control one ceiling fan and light per student and working on the following two observations. 1.Chair in the cabin is free 2.Chair in the cabin is not free 5.System Hardware Description Theproposedsystemisdevelopedbycombininga moduleoflightsensor,temperaturesensor,electronics componentsandpressureswitch.Theinterfacingofthe resultedmodulethroughPMSisshowninFig.1and hardware setup of each PESS is shown in Figs. 2 and 3. 6.System Operating Functions TheblockdiagramisshowninFig.1describesthe proposed system control units. S.Z. Hassan et al. / The Nucleus 52, No. 1 (2015) 1-8 3 PMSAC/DCConverterZero Crossing DetectorLight SensorTemperature SensorPressure SensorAC Voltage SourceSignal AmplifierAC Voltage Controller AC LightLCDDC/DC Buck ConverterAutomaticManualMode SelectorVariate KnobDC Fan Fig. 1: Block diagram of proposed system LCDAC SourceDC FanAC LightPMSLight SensorAC Voltage Cont roll erTemperat ure SensorDC Buck Converter Fig. 2: Hardware test bed of PESS Fig. 3: Test bed installed in the library 6.1Control System for Lighting ForlightingcontrolsystemtheLDRisused,which sensetheintensity of light insidethecabin andchangesits resistance(RLDR)accordingly.Therelationshipbetween RLDRandtheoutputvoltageisgivenby(1).Fig.4shows thecompleteblockdiagramofthelightingcontrolsystem. VLDRisfedtotheADC(AnalogtoDigitalConverter)pin ofthemicrocontroller(MCU)whichprovidesthePWM signalaccordingly.Here,asinglephasebi-directional controlledinverterisused.TherelationshipbetweenVLDR and Vlightisgiven by(4)and(5). Theworkingvoltageand power of AC load is 50Hz 220V 100W. 5 (Volts)10kLDRLDRLDRRVR= +(1) 6.2.Control System for Ceiling Fan Control System for ceiling fan is working in two modes, automaticandmanual.Inautomaticmode,LM35isused, which sense any small variations in temperature to give the outputvoltage.LM35sensorcandetectavoltageof1.5V, but theADC pin ofmicrocontrollerwork on 5V. Since, an amplifier is used with desire gain to amplify the input to the requiredlevelandthendctodcconverterisusedto regulate the fan speed according to the PWM signal sent by the MCU as shown in Fig. 5 (a). Similarly, in manual mode, the speed of ceiling fan is manually controlled via regulator according to the users rules as shown in Fig. 5 (b). (Volts)t roomV T = (2) 3.33 (Volts)temp tV V = (3) S.Z. Hassan et al. / The Nucleus 52, No. 1 (2015) 1-8 4 AC Voltage ControllerTRIACAC Voltage SourceElectrical Lamp PWM SignalVlightVLDRADC/Pulse DecoderConversion (Binary into Delay in s)ybPMS Fig. 4:Block diagram of lighting system TemperatureSensorVoltageAmplifierVtempADC/Pulse DecoderConversion (Binary into Delay in s)ybPMSPWM SignalDC-DC Buck Converter DC LoadVfan (a) ADC/Pulse DecoderConversion (Binary into Delay in s)ybPMSPWM SignalDC-DC Buck Converter DC LoadVfanManual RegulatorVref (b)Fig. 5: Block diagram of fan control system (a) automatic (b) manual 6.3.Student Detection System Thestudentinachairisdetectedusingapressure sensor.TheUltra-Fireremotepressureswitchisusedasa sensor.Thispressuresensorcontainsfourswitcheswhich arefixedonthechair.Theseswitchesareconnectedin parallel combination. These sensors activate when a student sitsonthechair.Thesesensorsareconnectedtointerrupt pin of the microcontroller. 6.4.Power Management System The overall control strategy of PESS is shown in Fig. 6. InitiallythePMSsensestheroomtemperature(Troom)and intensityoflight(VLDR)inthecabin.ThePMS continuouslymonitortheinterruptsignalprovidedby pressureswitchfor detectionofstudent.When a student is detectedthePMSsetthefiringangleoftheACvoltage controllerto itsmaximumvalue(max)and lightwill OFF. If VLDR isatitsmaximumvaluei.e. 5V,PMSsetfiring S.Z. Hassan et al. / The Nucleus 52, No. 1 (2015) 1-8 5 Detect StudentCalculateVLDR, TroomNoYesVLDR0From 1Goto 1YesNoVlight = Eq (2) = maxGoto 1Power onVlight=0VLDR < 5V = 0NoVlight=VmaxGoto 1Yes = 36VLDRMode SelectorYes(Automatic)No(Manual)Troom>TminManual RegulatorVfan = VinGoto 1Vfan=0NoYesTroomTmax,thefanoperatesonits maximum speed and for Troom