High-Efficiency Voltage Regulator and Stabilizer for Outdoor Lighting Installations

Transcription

1 High-Effiieny Vltage Regulatr and Stabilizer fr utdr Lighting Installatins F. R. Blánquez, E. Rebll, F. Blázquez and C. A. Plater P. Frías Abstrat This paper presents a high perfrmane system f regulatin and stabilizatin f luminus flux fr publi street lighting installatins. Its purpse is t redue the luminus flux f the luminaries effiiently by reduing their vltage supply, resulting in the imprvement f energy effiieny in the installatin. The system is basially mpsed f eletrmagneti mpnents whih prvide rbustness and high-perfrmane t the devie, as well as minimum maintenane requirements. Hwever, the vltage regulatin is based n the appliatin f vltage steps. Aging studies f the luminaries have been arried ut t analyze the impat f this disrete vltage regulatin. A speifi prttype f this vltage and stabilizer regulatr have been in peratin in a real utdr lighting installatin fr mre than ne year. Index Terms vltage regulatr, utdr lighting, energy effiieny. NMENCLATURE Input vltage V L Lad vltage Vriprim Transfrmer primary winding rated vltage Vrise Transfrmer sendary winding rated vltage VT2 P rim Transfrmer 2 primary winding rated vltage Vr2se Transfrmer 2 sendary winding rated vltage Vmin Vltage stabilizer lwer limit set pint Vmax Vltage stabilizer upper limit set pint r\ rati f transfrmer r 2 rati f transfrmer 2 I. INTRDUCTIN Energy effiieny and energy saving are nwadays pririties fr any enmy, and they an be ahieved withut affeting the dynamis f their ativity, als enhaning the mpetitiveness f their prdutin presses and reduing bth emissins f greenhuse gases and energy lsses. ne area under study amng the energy effiieny field is street lighting. The energy nsumptin f street lighting in Eurpe (EU25) was ver 35 TWh in 2005, whih aunts fr.3% f the final eletriity nsumptin in Eurpe. This nsumptin has negative envirnmental effets, suh as arbn dixide emissins and light pllutin. The ptential saving in publi lighting by using effiient tehnlgies is really high [],[2]. Currently there is a lak f implementatin f energy effiient tehnlgies and in many plaes the lighting levels used are muh higher than remmended. In fat, in Spain, the existing legislatin n this tpi speifies that publi utdr lighting installatins (street lighting, speial lighting, derative lighting and lighting f signs and nen lights) with an installed pwer exeeding 5 kw must be designed with partiular devies t regulate the lighting level [3]. Arding t this Spanish rule, the lighting level ntrl systems shuld be able t derease up t 50% the emitted lighting flux f its value during peak hurs, maintaining the unifrmity f the light alng the whle installatin. There are different types f lighting level ntrl devies: ) series indutive type ballasts fr dual pwer level [4]; 2) pwer ntrlled eletrni ballasts [5],[6]; and 3) regulatrs and stabilizers in the head f the line. The hie f the lighting level ntrl system will be determined by several fatrs inluding the vltage variatin f the lamp, the status f the main supply f the lamp, the lamp type r the number f hurs f peratin. The main prblem f using ballasts fr dual pwer level is that these systems at lally, requiring an adjustment devie attahed t eah f the individual harges and als a general ntrl system t ntrl all f them. This translates int a high initial investment as well as high demanding maintenane requirements. Certainly, these systems prvide very aurate regulatin, far frm the real regulatin requirements in street lighting. S this makes them t mplex and expensive systems, nt ptimal fr the use t whih they are intended [7]. Mrever, mst f the urrent systems used as stabilizers and regulatrs in lighting ntrl are derived diretly frm vltage stabilizers based n pwer eletrni. Beause f the nnlinearity inherent in the semindutr devies used in pwer eletrni devies, the input urrent wavefrm will have sme harmni distrtin and this will affet t the urrent ttal harmni distrtin (THD) f the netwrk [8]. The devie that is presented in this paper an be fund in the grup f eletrmagneti regulatrs and stabilizers installed in header line, amng the supply netwrk and the line f lamps. This regulatr and stabilizer has been designed arding t the results f a previus design f a vltage regulatr fr rural netwrks [9]. The luminus flux ntrl is reahed by regulating the vltage level f the lamps that mpse the street lighting

2 installatin. The key is that the luminus flux, the vltage and the pwer f the lamps vary prprtinately. Thus, a redutin f 50% f utput light implies a redutin f apprximately 40% f the pwer nsumed by the faility (depending n the type f lamp), with the energy savings and redutin f emissins t the atmsphere that it als entails. Due t the vltage regulatin f the system presented is based n the apliatin f vltage steps, aging tests have been arried ut in rder t verify that this disrete vltage regulatin desn't affet the life f the lamps. Anther imprtant pint t be nsidered is the frequent hange in the level f vltage that urs n a regular supply netwrk. These sillatins are usually less than 7% f rated vltage f the netwrk [0]. Beause f its harmful effet n the lamps, there is a need f installing a stabilizer system in rder t keep the vltage within preset margins. This avids the lamp's shutdwn / ff when the supply vltage is lwered t far. The stabilizer system als maintains the energy saving sheme despite the signifiant inreases f the supply vltage. This paper presents a new vltage regulatr and stabilizer that redue the luminus flux effiiently by reduing the vltage supply. Setin II presents the design f the vltage regulatr, desribing the pwer iruit and ntrl iruit. The lamp perfrmane test and aging test are desribed in setin III and IV respetively. Setin V presents the experiene data related t a real installatin where a prttype f the new regulatr has been tested. II. VLTAGE REGULATR AND STABILIZER. PRINCIPLE F PERATIN. This wrk prvides an effetive methd f lighting regulatin fr utdr lighting installatins and, therefre, it presents an effiient predure fr saving eletri energy. The system presented is haraterized by the use f eletrmagneti devies suh as transfrmers and ntatrs. This is ne f the main differenes mpared t urrent systems based n pwer eletrni devies. A. Pwer iruit The pwer iruit f a ne phase regulatin and stabilizatin system nsists f tw subsystems in a series nnetin, the Stabilizer (a) and Regulatr (b), shwn in Fig.. The nfiguratin f bth subsystems is based n a tw-winding transfrmer. Bth stabilizer and regulatr primary windings and the utput vltage in eah ase, Vs and V L are nneted in series. These primary windings are als nneted in parallel with their input vltage, V and Vs. The vltage Stabilizer (a) nsists f a transfrmer (Tl), diretly fed frm the netwrk, Vj-, in its primary winding. The sendary winding is installed in series with bth the primary winding and the lad, the regulatin system in this ase. The rati f this transfrmer is designated as n. A ntatr (CI) nnets the system with the netwrk,. If this ntatr is nt energized, then Vs =, and the stabilizer is in bypassed psitin. The stabilizer has als anther ntatr (C2) whih allws the inversin f the Fig.. VT2prim I UAAAAAAJ ' T2 Regulatr Simplified sheme f a single phase Regulatr-Stabilizer. Vmax, Vmin Cmparisn mdule Fig. 2. Stabilizer Cmpensatin mdule Cntrl system f the vltage stabilizer. indued vltage plarity in the sendary winding by inverting the vltage plarity in the primary winding. Thus, the system an feed the lad by adding a vltage step t the input vltage frm the main netwrk, as psitive r negative value fr V t \. This setup prvides three different vltage ranges that an be applied t the input f the regulatr: V s = V S = Vl + Vrise V S = Vl- Vrise The lighting flux Regulatr (b) is made, in a similar way as the previus stabilizatin system, by a transfrmer (T2), with rati f r 2. The main feature f this new nfiguratin, as mentined, is that the primary winding is fed diretly frm the utput f the stabilizer Vs r, failing that, frm the netwrk,, while the sendary winding is nneted in series with the primary winding and the lad. Anther ntatr (C3) links the system with the installatin and when it ats, it is applied t the lamp a step vltage redutin, 2se- B. Cntrl iruit The ntrl system f the Vltage Stabilizer (Fig. 2) nsists f a vltage relay that is preset fr perating in a vltage range between V min and V max. These values represent ± 7% f rated vltage f the netwrk, V. When the vltage remains within the preset vltage range (V min, V max ), the stabilizatin system is nt invlved and the regulatin system is diretly supplied by the netwrk. VL ()

3 [ Input\ Regulatin mdule Mve C3 TABLE I CMPENSATIN STEPS - LAMP VLTAGE LEVEL - PERATING ELEMENTS STATE (: PENED, C: CLSED) Timer Luminus Flux Supply Vltage Vj Lamps Vltage Level VL CI C2 C3 Fig. 3. Regulatr Cntrl system f the vltage regulatr. In the event that the vltage V is nt in the preset vltage interval (V min, V max ), the perating element (CI) is exited and the stabilizatin system keeps nneted t the installatin. In this ase there are tw ptins: In the event f V > V max, the swithing element (C2) ats. The primary winding f the transfrmer (Tl) is then fed by the supply netwrk vltage, V, s that, in its sendary winding, it indues a vltage (Vj / r\), and the regulatin system (b) is supplied with a vltage Vs, given by v s = v I (i - i/n) (2) In the event f V < V min, the swithing element (C2) ats. The transfrmer's (Tl) primary winding is nw fed by the supply netwrk vltage, V, s that, in its sendary winding is nw indued a vltage {-V I r\), and the regulatin system (b) is fed with a vltage Vs, given in this ase by V s = V I -(l + l/r ) (3) Fr the regulatin system (Fig. 3), a preset sensr (time relay, astrnmial lk, phteletri sensr, et.) gives the mmand t nnet the regulatin. It auses the exitatin f the perating element (C3). The perfrmane f the perating element (C3) drives the regulatin system. The primary winding f the transfrmer (T2) is nw pwered by the vltage Vs, the utput vltage f the stabilizatin system. Then, in the sendary winding f the transfrmer, a vltage Vs/ r 2 is indued, s the vltage in the lamps is V L, given by V L = V S -(- l/r 2 ) (4) In ase f the perating element (C3) is nt energized, the regulatin system des nt get invlved and the vltage level n the lamp is the stabilizer utput vltage. In this ase the regulatr is in bypassed psitin. In Table I the lamp vltage level fr eah mbinatin f perating elements state is summarized. C. Devie Features The harateristis and nfiguratin f the stabilizatin and ntrl system make the desribed system an ptimum system t meet the needs that an installatin f street lighting requires, inluding: 00% Redued flux Vmin ^ VI ^ * max Vl>Vm ax V!<V m V rnin <V<V m ax >V m ax v I <v m zn VI VI ( - l/r-i) ( + l/r-i) ( - l/r-2) ( - l/r-2)- ( - l/r-i) ( l/r-2)- ( + l/r-i) High Perfrmane: Fr a lamps line that demands a pwer designated S (5), being typially V=230V, the transfrmer used fr the stabilizer system desn't need t manage all this pwer, as ther systems d. This is an auttransfrmer nfiguratin, whih allws wrking with a redued size pwer transfrmer. Thus, fr the stabilizer, the transfrmer's pwer shuld be abut S\ (6), and fr the regulatr, its transfrmer's pwer wuld be abut S 2 (7), where Vri se and Vr2se are muh smaller than V, and thus 5i and S 2 muh smaller than S. This means that, unlike atual existing mdels, fr the same funtinality, this new system ffers a nsiderable redutin in pwer lsses, size, weight and levels f mplexity. S = V*I Si = Vpise * I S 2 = Vr2se * I Disrete step vltage regulatin: The disrete steps are btained arding t the supply netwrk flutuatins in the nnetin pint, and the admissible vltage redutin f the supply vltage f the lamps, whih depends n the lamp type. Rbust: It is a devie typially installed utdrs, usually in diffiult aess areas. Fr greater reliability and easy maintenane, it is better t use eletrmehanial ntatrs than pwer eletrnis. Reliability: In additin t ensuring high reliability levels, in ase f system failure the regulatr is nneted in bypassed psitin and this prvides a ntinuus and uninterrupted energy supply fr lighting. Lw st: Using serial vltage mpensatin instead f a full pwer nverter redues the devie size and st, inreasing the effiieny ntably. Versatility: The system is able t present ne-phase r three-phase nfiguratins. (5) (6) (7)

4 TABLE II LAMPS WRKING PINT FR 50% F FLUX REDUCTIN Lamp H. P. Sdium Metal Halide ptimal AU (V) 40,73 36,89 Energy saving (%) 33,3% 35,% Fig. 4. Vltage (V) 90 V H.P. Sdium ptimal perating pint _ : J /Ndj!/m ll f Fig. 6. Transient study during vltage swithing. Fig. 5. III Vltage (V) 83 V Metal Halide ptimal perating pint. LAMP PERFRMANCE TEST. This system is designed fr the ptimizatin f publi lighting installatins, ften using High Pressure Sdium r High Pressure Merury Vapr disharge lamps type, Metal Halide, et. Eah type f lamp allws a redutin in vltage limited by a minimum vltage level at whih the lamp just swithes ff. Furthermre, the gal f reahing the mentined 50% luminus flux redutin per lamp will require a different vltage redutin in eah ne due t the different prperties f any type f lamp. Cnsidering these nditins, a prtl test has been arried ut in the labratry t find the ptimal peratin nditin (maximum allwable vltage redutin) fr eah type f lamp. By taking measurements f luminus flux fr different vltage levels, we nlude the ptimal level f vltage redutin. Thus, in ase f HP sdium lamps (80 W), we nlude that t ahieve 50% redutin in luminus flux, it is neessary t redue the lamp vltage in V, ahieving energy savings f W per lamp, 33% f the pwer nsumed withut the regulatin system. The mplete test results are shwn in Fig. 4. In the same way, metal halide lamps (70 W) reah a redutin f 50% luminus flux by reduing vltage in V, ahieving energy savings f W, 35.% f the nsumed pwer. The mplete test results are shwn in Fig. 5. In table II the ptimal wrking pint and energy saving fr IV 240 eah tehnlgy is summarized. It has been verified that the vltage redutin is assiated with a redutin in luminus flux and energy nsumptin, but different fr eah lamp. As nted, Spanish rules restrit the flux redutin up t 50% in the hurs in whih the regulatin system perates. In the partiular ase f HP sdium lamps, the vltage redutin needed t ahieve the 50% f flux redutin is 40.73, far frm the 47 V f the lamp threshld. Fr any flux lighting redutin, the results shwn in Fig. 4 and Fig. 5 are useful in rder t design the vltage regulatr. In ase f fluresent lamps (less mmn lights in publi lighting failities) the redutin f luminus flux and pwer is milder than with the ther lamps, s it is very diffiult t btain the 50% f flux redutin by reduing the supply vltage and aviding the wn fluresent lamp threshld. Fr this type f lamps a vltage redutin f 40 V nly implies a redutin f % f the luminus flux. IV. EXPERIMENTAL TEST. LAMP AGING TEST. The vltage swithing applied t the lamp by this new regulatin system, withut any element f an eletrni nature, is sharp. This fat is presented as ne f the main drawbaks f the system beause it uld aelerate in the aging press f the lamp. The vltage and urrent variatin deteted in the lamp due t the perfrmane f the ntrller is shwn in the Fig. 6. After nduting numerus surveys, we fund n vltage peak t dangerus n the lamp, and at n time did the lamp me t turn ff beause f these swithes. During the tests n majr prblem has been fund. A speifi test has als been arried ut t bserve the behavir f light t these lng-term atins. In a labratry several test have taken plae

5 ' ' I h \ V X P > 5 _ f _ ^ _ ^ Metal Halide 230 V max. vltage Y J/f Maneuvers 0 Hurs V min. vltage \^y /y ['Z. Fig. 7. Metal Halide lamp aging test. Fig. 9. Vltage stabilizer and regulatr prttype. _uu u - * 3 C 5 C 3 t 3 00 i 3 H.P. Sdium 230 V max. vltage 205 V min. vltage euvers Hurs Fig H. P. Sdium lamp aging test Fig. 0. Emplaement f the real studied installatin. by feeding different types f lamps thrugh a stabilizer and regulatr devie as the ne presented in this paper, during a relevant time perid, s the lamps have suffered muh higher amunt f peratins that suffer thrughut their life in a line f street lighting. A. Lamp Features. The test detailed here has been perfrmed fr bth metal halide and HP sdium lamp. Arding vendr-features, its life is between 2,000 t 6,000 h fr the metal halide lamp and between 8,000 and 2,000 h fr the HP sdium lamp. As the lamp usually remains n an average f 8 hurs and suffers tw perfrmanes f the regulatr per day, it is estimated that, thrughut its whle life the lamp will suffer arund 3,500 maneuvers, if nly the regulatin system wrks. B. Test nditins. The lamp has remained nstantly swithed n, t the ntinuus peratin f the regulatin system by intrduing this peratin every 2 minutes (established after a study perid f warming and stabilizatin f light utput by the lamp). C. Current status f trial. At the end f the test, the lamp had been tested fr apprximately 0,000 hurs, whih means abut 300,000 maneuvers. The luminus flux level and its variatin have been registered during the test duratin. In Fig. 7 and Fig. 8 are shwn the illuminane variatin during the test f a metal halide lamp and a HP sdium lamp, respetively. This variatin is negligible despite the intrdutin f the regulatin system. Therefre, we an nlude that the results f these tests were satisfatry and it an be said that the perfrmane f the presented system des nt affet r prejudie the nrmal peratin f the lamps. V. REAL UTDR LIGHTING INSTALLATIN. A prttype (Fig. 9) f the luminus flux regulatr presented in this paper has been in peratin fr mre than ne year. The develped prttype has 2 transfrmers. First, a tw-winding single-phase transfrmer (V ) and 3000 VA f pwer fr the vltage regulatr, and send, a tw-winding singlephase transfrmer (V 230-8) and 960 VA f pwer fr the vltage stabilizer transfrmer. The peratin f the regulatr system attahes a fixed vltage redutin f 25 V t the lamps,

6 TABLE IV VLTAGE REGULATR AND STABILIZER DATA Stabilizer Transfrmer Primary Sendary Nn lad lsses Lad lsses Regulatr Transfrmer Primary Sendary Nn lad lsses Lad lsses Regulatin Step SI S2 S3 S4 Vltage 230 V 8 V Vltage 230 V 25 V Current 4.8 A 20 A Current 3.04 A 20 A Pwer 960 VA 960 VA 9.2 W 76.8 W Pwer 3000 VA 3000 VA 25. W 04 W + 0 V - 25 V ± 8 V - 25 V ± 8 V Pint A B C D F G H I J K Fig.. Real lighting line and measuring pints. TABLE III ILLUMINANCE REDUCTIN Regulatr FF Illuminane (lx) Regulatr N Illuminane redutin (%) while the stabilizer systems applies an step f ± 8 V t the lamps. Besides the design and the aging tests, the desribed prttype has been installed in a real street lighting installatin in rder t evaluate the peratin f the devie. A. Installatin Data The lighting installatin whih has been hsen is lated in the ar park f the Esuela Ténia Superir de Ingeniers Industriales in Madrid (Fig. 0). The light line is mpsed by 0 lamps, metal halide, with a pwer f 2800 W supplied t the whle line. The prpsed devie was easily set up between the netwrk and the lamps line. As desribed, the system had been set in rder t redue the lamp vltage 25 V when the regulatr wuld at and ± 8 V when the vltage stabilizer wuld at. B. Luminus flux ntrl The light intensity in several pints ver the studied area (Fig. ) has been heked after the regulatr at t keep TABLE V VLTAGE AND CURRENT REDUCTINS AND ENERGY SAVINGS IN THE REAL INSTALLATIN Vltage (V) Current (A) Ative Pwer (W) Apparent Pwer (VA) Regulatr FF , 806 3, 7 Regulatr N ,62 2, 080 2, 230 TABLE VI EFFICIENCY PWER FACTR Lad (p.u.) SI S2 S3 S TABLE VII EFFICIENCY PWER FACTR 0.8 Lad (p.u.) SI S2 S3 S Redutin (%) the limits established by the standards. It means that during the atuatin f the regulatr the luminus flux desn't have t be redued mre than the 50% f the flux in nrmal nditins. This pint is ahieved by the system. The luminus flux measured in the measuring pints during the test and the luminus flux redutin is summarized in Table III. C. Energy saving and lsses in the devie. In Table IV the tehnial data f the regulatr and stabilizer prttype is summarized. It has t be nsidered that the vltage stabilizer and regulatr an manage up t 20 A, s it is versized mpared t the lighting installatin in where it is in peratin. Table V shwn the redutin f the vltage, urrent and pwer, nsidering nly the peratin f the regulatr. The energy nsumptin is redued by 726 W, whih represent mre than the 25% f the ttal energy

7 nsumptin. The energy saving is remarkable. The effiieny f the prttype has been tested in the labrarry. Several tests have been arried ut with different lads at pwer fatr and pwer fatr 0.8. The results f the effiieny tests are shwn in Table VI and Table VII, where 5* Bypassed psitin 52 Regulatr nneted 53 Stabilizer nneted 54 Regulatr and Stabilizer nneted D. Energy saving freast. The lights are swithed n fr 0 hurs a day, it wuld represent a nsumptin f 0,220 kwh a year. The regulatr is set up in rder t perate during the less upatin hurs, 6 hurs a day. The nsumptin is redued till 8,600 kwh, measured last year. It means an energy saving f mre than,600 kwh a year. VI. CNCLUSIN The stabilizer-regulatr system presented in this paper inrprates sme imprtant tehnial advantages that makes it ideal fr use in street lighting installatins: The nfiguratin f the system an supply pwer fr lamps between tw vltage levels, as well as ffset the frequent vltage flutuatins in the lamp. The system des nt aelerate the aging press f the lamps as demnstrated experimentally. A single devie an adjust all the lamps in a single line between tw vltage levels withut an individual ntrl devie fr eah lamp. It is based n the use f eletrmagneti harater elements, whih gives it great rbustness and has minimal maintenane requirements. The devie manufaturing press wuld be simple, enmial and it des nt require a high speialist labr. Experimental data btained frm the peratin f the stabilizer-regulatr in a real lighting faility have shwn its reliability and high perfrmane. [4] Wei Yan and S.Y.R. Hui, "Dimming Charateristis f Large-sale High- Intensity-Disharge (HID) Lamp Lighting Netwrks using t Energy- Saving Pwer statin System" in Pr. IEEE Industry Appliatins Cnferene, 2006, Vl. 3, pp [5] Wei Yan and S. Y. Hui, "An analysis int the dimming ntrl and harateristi f disharge lamps," IEEE Trans. Pwer Eletrnis., Vl. 20, Issue 6, pp , Nv [6] S. Chen, B. Mulgrew, and P. M. Grant, "Pratial evaluatin f dimming ntrl methds fr eletrni ballasts," IEEE Tram. Pwer Eletrnis., Vl. 2, Issue 6, pp , Nv [7] H. S.-H. Chung, Ngai-Man H, Wei Yan, Pk Wai Tarn and S.Y Hui, "Cmparisn f Dimmable Eletrmagneti and Eletrni Ballast Systems An Assessment n Energy Effiieny and Lifetime," IEEE Trans. Industrial Eletrnis., Vl. 54, Issue 6, pp , De [8] E. Bmpard, E. Carpanet, G. Chi, P. Ribaldne and C. Verellin, "The impat f publi lighting n vltage distrtin in lw vltage distributin systems," IEEE Trans. Pwer Delivery., vl.6, Issue 4, pp , t 200 [9] P. Frías, C. A. Plater, D. Sler and F. Blázquez, "High-Effiieny Vltage Regulatr fr Rural Netwrks," IEEE Trans. Pwer Delivery., vl.25, Issue 3, pp , July 200 [0] RD 955/2000 de de diiembre pr el que se regulan las atividades de transprte, distribuión, merializaión, suministr y predimients de autrizaión de instalaines de energía elétria, B..E., De. 27, 2000, Spain. [nline]. Available: ACKNWLEDGMENT The authrs wish t aknwledge the tehnial supprt f Nrma Garia. The design f the vltage Stabilizer and Regulatr presented is this paper is under patent P , tber 27th 20, "High effiieny luminus flux regulatr fr lighting installatins". REFERENCES [] Intelligent Energy Eurpe, "Guide fr energy effiient street lighting installatins," Eurpean Cmmissin - Exeutive Ageny fr Cmpetitiveness & Innvatin (EACI), [2] Intelligent Energy Eurpe, "Prjet Reprt. Intelligent Rad and Street lighting in Eurpe," Eurpean Cmmissin - Exeutive Ageny fr Cmpetitiveness & Innvatin (EACI), [3] RD 890/2008, de 4 de nviembre, pr el que se aprueba el Reglament de efiienia energétia en instalaines de alumbrad exterir y sus Instruines ténias mplementarias EA-0 a EA-07, B..E., Nv. 9, 2008, Spain [nline], pp Available: