JJMIE Jodn Jounl of Mechnicl nd Industil Engineeing Volume 3, Numbe 3,Septembe 2009 ISSN 1995-6665 Pges 216-221 Wte Pumping System with PLC nd Fequency Contol Akyleh Ali,* b b c, Mohmmed Al_Soud, Essm Abdllh, Slh Addllh Deptment of Electicl Engineeing, Tfil Technicl Univesity, Tfil, Jodn b Deptment of Mechnicl Engineeing, Al- Blq Applied Univesit y, Ammn, Jodn c Deptment of Mechnicl nd Industil Engineeing, Applied Science Univesity, Ammn, Jodn Abstct In this study contolled wte pumping system is designed, constucted, nd modeled. The pogmming method of contol of pumping flow te is chieved by mens of integted pogmmble logic contolle (PLC nd fequency invete (FI. PLC min function is to detemine the equied flow te levels nd the elted time intevls of the flow te hold time. (FI is used to contol the dynmic chnge of tempetue between vious opeting points. The designed system shows the cpb ility fo full contol of pumping flow te fom zeo to mximum fo ny equied nge of time in cse of incesing o dece sing the pumping flow te. All vibles of the system will be chnged gdully until eching thei needed woking points.the mthemticl model of wte pumping system with PLC nd fequency contol is built bsed on MATLAB- SIMU LINK. A test ig built nd n expeimentl study ws pefomed. Fom the nlysis of the expeimentl stting dynmic chcteistics of wte pumping system nd modeled chcteistics, it ws noticed tht they e vey simil. Keywods: PLC; Fequency Contol; Wte Pumping System; Dynmic Chcteistics. 2009 Jodn Jounl of Mechnicl nd Industil Engineeing. All ights eseved 1. Intoduction * Pumping equipments in the moden mnufctuing systems my be used s min pts in mny industil ctivities, like chemicl industies, food industies, etc. The utomtion of the pumping pocesses in those industies will cetinly led to impove thei pefomnce [1].In Jodn bout 18% of geneted electicl powe is consumed by thee-phse-induction motos diven centifugl pump in wte pumping sttions. Fom the nlysis of the woking conditions of wte pumping systems, it is noticed tht thee e mny poblems, which fce the wok of such systems, s hydulic hmmes, dynmic stesses in mechnicl pts, high stting cuents in the thee-phse -moto diven centifugl pump, nd enegy sving poblems [2]. A new single-switch pllel esonnt convete fo induction heting ws intoduced in [3].The cicuit consists of n input LC-filte, bidge ectifie, nd only one contolled powe switch. The switch opetes in soft communiction mode nd seves s high fequency geneto. A voltge-fed esonnt LCL invete with phse shift contol ws pesented in [4].It ws obseved tht the contol sttegy offeed dvntges in the meghetz opeting egion, whee constnt switching fequency is equied. The invete stedy stte opetion is nlyzed using fundmentl fequency nlyses. A cost-effective high efficiency invete with phse shifted pulse modultion scheme ws poposed fo medium powe (5-30 kw induction heting pplictions is discussed in [5]. T he poposed invete ccomplishes soft switching o petion ove wide powe egultion nge. The ctul powe convesion efficiency eched ws 96.7%. A contol method of educing the size of the dc-link cpcitos of convete-invete system ws pesented in [6]. T he min ide is to utilize the invete opetion sttus in the cuent contol of the convete. This contol st tegy is effective in egulting the dc-voltge level. Even the dc-link cpcito is bitily smll nd the lod vies buptly. In [7], method ws poposed to ccutely pedict the minimum equied tempetue ecovey, consideing epetbility nd ccucy of the lek detecto by investigting the eltion between tempetue ecovey time nd pplied pessues using PLC system. A methodology ws demonstted to design P LC pogm tht ognizes the eltion between the physicl inputs nd outputs of the pumping tools in mnufctuing systems. In [8], n expeimentl study ws pefomed to investigte the effect of using two xes tcking with PLC co ntol on the sol enegy collected. The two xes tcking sufce showed bette pefomnce with n incese in the collected enegy up to 41% comped to the fi xed sufce. This study seeks to design, model, nd expeiment of fully utomted wte pumping system with P LC nd fequency contol, whee the min PLC function is to contol the equied flow te levels nd the elted ti me intevls of the pumping flow te hold time. FI is * Coesponding utho. kyleh_em@yhoo.com.
217 2009 Jodn Jounl of Mechnicl nd Industil Engineeing. All ights eseved - Volume 3, Numbe 3 (ISSN 1995-6665 used to contol the dynmic chnge of pumping flow te between vious opeting points. 2. Wte Pumping System Design nd Contol Fo the pupose of expeimenttion, the electomechnicl system PLC-FI-Thee phse induction moto-centifugl pump pipeline ws designed nd constucted s shown in figue1. Q /Q =n (1 Whee: Q : The ctul flow te of wte. Q : The ted flow te of wte. n : The ctul speed of moto. n : The ten speed of moto. To investigte the system pefomnce duing stting towds diffeent input signls, the fequency contol lws which epesent the fequency function of time, shown in Figue 2, wee used. The contol lws wee stted fom th e bse fequency of 10 Hz though the stting time to e ch efeence fequency of 50 Hz. In cse of diect co nnection to the supply netwok, the stting time equls ze o s shown in cuve 1 of figue 2, which epesents step signl [11]. Figue 1.Wte pumping system with PLC nd fequency contol. Both the design of PLC nd fequency contolled pumping system wee pefomed, using n open loop nd pogmming method of contol in which stoed instuctions in memoy of PLC ws used to contol the pumping flow te. PC is pesonl compute which is used to wite the contol pogm; then downlod it to the PLC though communiction cble. The PLC is S7-200 type, which hs 12 inputs, 8 outputs nd 220 VAC supply voltge [9].The PLC min function is to instuct the nlog unit to go on o off nd to stte the equied pecentge output nd the elted hold time intevls. The nlog unit function is to tnsfe the digitl output vlue t the output of PLC into nlog vlue, which nges fom zeo to 10 VDC t the output of the nlog unit. In the contol pogm, diffeent pecentges of output voltge e supplied to the AC moto diven centifugl pump by the fequency invete, which is oiginlly stted by the nlog unit output, whee 0 VDC equls 0% t the output of the fequency invete nd 10 VDC equls 100% t the output of fequency invete. FI is one-phse input, thee-phse output with ted powe of 0.95 KVA nd ted output cuent of 2.5A. ACM is thee -phse induction moto with ted powe of 0. 37Kw t 50 Hz, nd with voltge of 240V nd cuent of 1.8A fo connection [10]. P is centifugl pump which hs the following dt: flow te 10-30 L/min, hed 14-22m nd nominl impelle speed 2900 pm. P connects the uppe nd lowe tnks with 0.5 inch steel pipes to povide n unlimited wte supply fo the system. TV is thottling vlue which could be used fo vying the flow te mnully. A ventue mete ws used to mesue wte flow te, nd stop wtch ws used to mesue the time. The ottionl speed of the pump impelle ws clculted using the following popotionlity eqution: Figue 2. The pogmmed input fequency of time in cse of stting The cuves 2, 3 nd 4 in Figue 2, whee obtined by using diffeent mp signls with stting time equl to 2 seco nds, 3 seconds, nd 4 seconds espectively. Accoding to the diffeent inseted contol lws, the output flow te o f the wte pumping system in stting condition chnge s time function s shown in figue 3. Figue 3. Flow te vs. time ccoding to the diffeent inseted contol lws Accoding to the diffeent inseted contol lws, the output pump speed of the wte pumping system in stting condition chnges s function of time s shown in Figue 4.
2009 Jodn Jounl of Mechnicl nd Industil Engineeing. All ights eseved - Volume 3, Numbe 3 (ISSN 1995-6665 218 speed of the wte pumping system e shown in Figue 6 nd figue 7. Figue 4. Speed vs. time ccoding to the diffeent inseted contol lws. Fom the nlysis of stting cuves in Figues 3 nd 4, it cn be noticed tht in cse of stting with step input signl, ll output pmetes of the wte pumping system including speed nd flow te exhibited high pek vlue with fluctution until eching the ted vlues. Consideing othe contol lws, the nge of vibtions decesed s time incesed. Setting the stting time to 3 seconds exhibited vey smll oscilltions tht cn be neglected. While setting the stting time to moe thn 3 seconds exhibit no oscilltions [12, 13]. Figue 5 shows the vition of pogmmed fequency function of time. The contol lw ws stted fom the bse fequency of 0 Hz to ech 12.5 Hz with in 10 seconds, fte tht, the fequency will be stble fo 15 seconds, then the fequency will be chnged softly fom 12.5 Hz to the 25 Hz though 10 seconds, lte the fequency will be stble fo 15 seconds, then the fequency will be chnged softly fom 25 Hz to 37.5 Hz though 10 Seep, fte tht the fequency will be stble fo 15 seconds, lte the fequency will be chnged softly fom 37.5 Hz to 50 Hz though 10 seconds, fte tht the fequency will be stble fo 15 seconds, next the fequency will slow down softly to 25 Hz though 10 seconds, fte tht the fequency will be stble fo 20 seconds, then the fequency will slow down softly fom 25 Hz to 0 Hz though 10 seconds. Figue 6. Flow te vs. time. Figue 7. Pump speed vs. time. Fequency invete, ccoding to the diffeent incoming instuctions of PLC though nlog unit, opetes the thee -phse moto with the equied pecentge of voltge nd fequency. Pmete unit is type of pogmme w hich is used to pogm the mp up nd mp down time between ech two contolled levels. So, fequency invete hs two types of commnds: 1. Type of commnds supplied by the PLC to the nlog unit then to the fequency invete to stte the equied level of flow te nd the hold time intevl. 2. Type of commnds supplied by pmete unit to c ontol the mp up nd mp down time to mke soft tnsition conditions between vious opeting levels. It cn be noticed fom the cuves in Figue 6 nd Figue 7 th t the expeimented system shows the cpbility fo full contol of flow te nd pump speed fom zeo to mximum fo ny equied nge of time in cse of incesing o decesing the flow te nd pump speed. All v ibles of the system will be chnged gdully until eching thei needed woking points [14, 15]. 3. Mthemticl Model of the System Figue 5. Input fequency vs. time The mthemticl model of wte pumping system with PLC nd fequency contol will be done by using MATLAB-SIMULINK gphicl intefce Figue 8. Accoding to the contol lw, shown in Figue 5, the expeimentl output flow te nd expeimentl pump
219 2009 Jodn Jounl of Mechnicl nd Industil Engineeing. All ights eseved - Volume 3, Numbe 3 (ISSN 1995-6665 Whee: H : The ctul hed of pump H : The ted hed of pump P : The ctul powe consumption P: The ted powe consumption Figue 8. Mthemticl model of wte pumping system with PLC nd fequency contol. The mthemticl model consists of two blocks ech of them hs specific function. Block 1- The min function of this block is epesent the vecto contol of vible fequency induction moto dive, which is vilble s built using MAT LB liby (see figue.9[16]. In this block the min input signls e: Rted ngul speed signl In 1 Full vlue of dc contolled voltge signl In 2,this vlue is elted of ted fequency of the system. PC o PLC voltge signl In 3 Rted lod toque signl In 4 Figue 10. System min equtions block. Output vlues of this block digm e pesented s the min system esponse s follows: Q H / Q = n / H = ( n 3 P / P = ( n Whee: H : The ctul hed of pump H : The ted hed of pump P : The ctul powe consumption P: The ted powe consumption 2 (2 (3 (4 Figue 9. Vecto contol of vible fequency induction moto dive. Block 2- This block contins the mthemticl equtions tht e esponsible fo the min equtions nd eltionships of pumping system clcultion. The min inputs of this block e the ted of pump system pmetes ( Q,H,P nd the ted nd ctul speed vlues of the induction moto (n, n (see figue.10. Output vlues of this block digm e pesented s the min system esponse s follows: Q H / Q = n P / P / H = ( n = ( n 2 3 (2 (3 (4 4. System Opetion nd Test Accoding to the pogmmed contol lw shown in Figue 5 s eltion ship between fequency nd time, the m odeled output flow te nd pump speed of wte pumping system e shown in figue 11 nd figue 12. Figue 11. The modeled flow te.
2009 Jodn Jounl of Mechnicl nd Industil Engineeing. All ights eseved - Volume 3, Numbe 3 (ISSN 1995-6665 220 gdully until eching thei equied opeting points. The poposed mthemticl model of the system successfully epesents the el behvio of wte pumping system with PLC nd fequency contol. Refeences Figue 12. The modeled pump speed It cn be noticed fom Figue 11 nd Figue 12 tht the flow te nd pump speed in modeled system showed the cpbility fo full contol fom zeo to mximum fo ny equied nge of time in cse of incesing o decesing. 5. Discussion nd Results PLC nd fequency contol of wte pumping cn be used in cses of dynmic conditions, fo exmple stting, beking, nd chnging fom one opeting condition to nothe. The using of PLC nd fequency contol of wte pumping system will chnge ll vibles of the system gdully until eching the desied opeting condition. Consequently, it is possible to pevent hydulic hummes nd dynmic stesses in mechnicl elements in wte pumping system. Also it is possible to void dynmic cuents in the thee-phse AC mchine. Fom the compison of the expeimentl cuves in Figue 6 nd Figue 7, nd the theoeticl cuves in Figue 10 nd Figue 11, it is obvoius tht they e vey simil. This mens theoeticl model cn successfully epesents the el behvio of wte pumping system with PLC nd fequency contol. 6. Conclusions In this wok, smll cpcity wte pumping system is designed, constucted nd expeimented by using PLC nd fequency contol. The designed system shows the cpbility fo full contol of flow te fom zeo to mximum fo ny equied nge of time in cse of incesing o decesing the flow te. It cn be concluded fom the expeimenttion of the wte pumping system tht ll vibles of the system would be chnged [1] S. Abdllh, A. Abdulkim, "Methodology to design n utomted pump plnts with PLC contol system". Poceedings of the Intentionl engineeing confeence. Muth-Jodn, 2004, 26-28 Apil, 373-398. [2] Abdllh S. "The egultion of stting nd beking dynmic chcteistics in wte pumping systems with open- Cio, loop contol". In poceedings of the 8th Cio Univesity confeence on mechnicl design nd poduction. Egypt; Jnuy 2004,4-6. [3] Shenkmn A. "Axelod B. Bekovich Y. Impoved modifiction of the single-switch AC-AC convete fo induction heting pplictions". IEE, Poc-Elect Powe Appl 2004,151(1,1-4. [4] Mollov, S.V., Theodoidis, M. "Fosyth AJ. High fequency voltge-fed invete with phse-shift contol fo induction heting". IEEE, 2003,12-8 [5] Kifune, H., Htnk, Y., Nkok, M. "Cost effective phse shifted pulse modultion soft switching high fequency invete fo induction heting pplictions". IEE, Poc-Elect Powe Appl,2004, 151(1,19-25. [6] Jung, J., Lim, S., Nm, K. "A feedbck lineizing contol scheme fo PWM convete-invete hving vey smll DC-Link cpcito". IEEE, Tns Ind Appl 1999, 35(5. [7] Hus, L.G., Ci, M., Kwhim, K., Kgw, T. "Detemintion of tempetue ecovey time in diffeentil- pessue-bsed i lek dete".detecto ".Mesuement Science nd Technology 17(2006 411-418. [8] Abdllh, S., Nijmeh, S. "Two xis sun tcking system with PLC contol". Issued Enegy convesion mnge,2004,45,193-199 [9] Siemens PLC, s7-200, "opeting instuction mnul". Issued, 06/02. [10] [10] Siemens Sinmics, G110, "opeting instuction mnul". Use documenttion issued,04/02. [11] M.Akn, D. Kostic-Peovic nd Unswoth P.J.2005, " Modelling nd Simultion of Induction Motos with Intelw fo Tun Fults fo Dignostics," Electic Powe Systems Resech, vol. 75, N. 1, pp.57-66. [12] T.Kmlov, S. Abdllh, "The choose of economicl fequency contol of centifugl pumps". Poblems of powe nd utomtion, Russi, Vol 4, 1994. [13] R.Willim, E. Robet, "Retofit of 22 pipe line pumping sttions with 3000-HP motos nd vible-fequency dives". IEEE, (34/ 1,1998,178-186 [14] L.Mnz, "Applying djustble-speed dives to thee phse induction NEMA fme motos". IEEE, 1997,Vol. 33, No. 2. [15] H.Jung-IK, S. Seung-ki, "Senso less field oienttion contol of n induction mchine by high-fequency signl injection". 1999,Vol. 35, 1. [16] Plm, III. W. (2005. "Intoduction to MATLAB 7 fo Enginees".1999, McGRAW-HILL.