SERCOS ENERGY SERCOS Iteratioal e.v.
Table of Cotets Short Overview of SERCOS Eergy 3 About SERCOS 3 Eergy Efficiecy i Figures 4 Classificatio of SERCOS Eergy 5 SERCOS Eergy Applicatio scearios 6 Short Breaks 6 Log Breaks 6 Uscheduled Breaks 6 Partial Machie Operatio 7 Partial Load Operatio 7 Measuremet ad Visualizatio 7 Advatages of SERCOS Eergy 8 Published by SERCOS Iteratioal e.v. Küblerstr. 1 73079 Süsse, Germay Tel.: +49 (0) 71 62 / 94 68 65 Fax: +49 (0) 71 62 / 94 68 66 E-Mail: ifo@sercos.de Iteret: www.sercos.de Author Dipl.-Ig. Ja Schlechtedahl Istitute for Cotrol Egieerig of Machie Tools ad Maufacturig Uits, Uiversity of Stuttgart Versio 1.0 (April 2010) 2 SERCOS ENERGY 2010 by SERCOS INTERNATIONAL
About SERCOS Short Overview of SERCOS Eergy The climate discussio has raised the public awareess of the eergy efficiecy topic. Withi the scope of this icreased attetio, more ad more products are beig promoted with referece to their eergy efficiecy. I this coectio, the gree image is i the foregroud but eergy costs play a importat role as well. However, most curret automatio products oly focus o the reductio of eergy cosumptio through the permaet improvemet of process chais, procedures ad machie efficiecies via structural measures. Because machies ad sys- tems are operated uder cotiuously chagig requiremets ad boudary coditios, such average optimizatio oly opes up a part of the eergy efficiecy potetial. Thus, mea - sures for eergy-optimal operatio ad cotrol of machies ad systems are required for overall eergy efficiecy. These measures must optimize the eergy cosumptio of machies ad systems depedig o the process ad exteral iflueces as well as depedig o the operatioal situatio. SErial Realtime COmmuicatio System, i short SERCOS, is amogst the leadig digital iterfaces for commuicatio betwee cotrols, motors ad decetralized peripheral devices. SERCOS has bee used i machie egieerig for more tha 20 years ad is implemeted i over 2,5 millio real-time odes. With the ope, maufacturer idepedet architecture o a Etheret basis, SERCOS III is a uiversal bus for all automatio solutios allowig for a itelliget cotrol of loads. SERCOS Eergy the Eergy Profile for the SERCOS III Etheret-based real-time commuicatios system allows the machie cotrols to switch coected compoets (drives, I/O, sesors) ito eergy-savig coditios, up to complete shut-dow, i a targeted form, cosiderably reducig their eergy cosumptio. For this purpose, SERCOS Eergy makes the compoets eergy cosumptio trasparet allowig for a itelliget cotrol of loads. SERCOS Eergy cosiders eergy-savig coditios for predictable breaks such as luch breaks ad plat holidays. At pre-defied times, SERCOS Eergy compoets are brought ito a stadstill coditio i order to save eergy. Shortly before the ed of the iterruptio, SERCOS Eergy provides for the re-iitializatio of the compoets i stad-by coditio i order to make them available agai with utmost precisio. Apart from that, SERCOS Eergy provides mechaisms for uiteded breaks that may be caused by machie errors ad missig parts. System compoets ca be brought ito eergy-savig coditios i a targeted maer while the errors are beig remedied or durig a wait for ew parts. With SERCOS Eergy, SERCOS III as the oly commuicatio system i the productio eviromet offers the possibility of savig eergy while still achievig full productivity. Usig itelliget cotrols, axes ad compoets that are ot ecessary i curret productio processes ca be switched off. Especially with flexible productio, the eergy savig that ca be achieved via SERCOS Eergy is eormous. 2010 by SERCOS INTERNATIONAL SERCOS ENERGY 3
SERCOS Eergy commads for switchig ito eergy-savig coditios are ormally set by the cotrol. This allows for itegratio of devices both with ad without the SERCOS Eergy profile ito the same machie. The subsequet retrofittig of machies that are already i the field with SERCOS Eergy is therefore possible ad reduces the eergy cosumptio i a sustaiable form. SERCOS Eergy allows for the efficiet, eergy cosumptio-optimized activatio of cotrol compoets dow to the sigle I/O termial. Eergy Efficiecy i Figures It is true that the primary eergy cosumptio i Germay has remaied almost costat sice 1990 despite a icrease i the gross domestic product by approximately 27%. This is, however, primarily attributable to a chage i the ecoomic structure. Accordig to curret figures of the Federal Statistical Office, i 2005 idustry was resposible for 27% of the fial eergy cosumptio. I Germay, 528 TWh of electrical curret were cosumed i 2004, 47% (248 TWh) of which were attributable to idustry. Accordig to the VDW s stock iformatio ad average cosumptio iformatio from the Ikarus database, istalled metalcuttig machie tools accout for a 10-15% share of eergy cosumptio. Through its power cosumptio, a average metalcuttig machie tool emits as much CO 2 as 70 passeger cars per year. Accordig to a study by ETH Zürich, 20% of the power cosumptio is lost i o-load operatio (Figure 1). 100% power 25 % required process power Figure 1: Typical power distributio i productio techology (source: IWF ETHZ) I the maufacturig idustry, the eergy itesity (kj iput per value added) is much higher tha the average of all ecoomic areas. I the metal producig ad processig idustry, the eergy itesity is eve oe scale higher ad also has bee icreasig i the last few years. I this coectio, the movig of eergy-itesive productio facilities to other coutries with partially lower evirometal stadards is o solutio for the problem. The practical implemetatio of measures for icreasig eergy efficiecy depeds o their ecoomic profitability. The exact predictio of the moetary cosequeces of eergy efficiecy measures is subject to fluctuatios of eergy prices. However, aother log-term icrease i eergy prices ca be assumed give the strogly icreasig global demad, particularly by deve- 15 % motor losses 30% ifrastructure 20 % o-load 10 % process losses 4 SERCOS ENERGY 2010 by SERCOS INTERNATIONAL
1 2 3 4 5 6 7 8 Coolig lubricat o Axis movemet rapid Start-up mai spidle Begiig millig process Ed millig process Spidle off Coolig lubricat off Permaet load durig stadstill lopig atios, ad the decreasig eergy offer. That meas that measures for icreasig eergy efficiecy that are profitable today are also suitable for the future. A eergy-efficiet productio system must also be highly productive ad able to flexibly react quickly to market requiremets. I order to reduce eergy cosumptio i the maufacturig idustry o a permaet basis ot oly i idividual solutios a stadardizatio of mechaisms for the situatio-depedet reductio of eergy cosumptio is ecessary. Apart from that, eergy cotrol circuits have to be desiged based o the provisio of cosumptio values that lead to the efficiet use of existig eergy ad productio systems. Based o these basic ideas, SERCOS Eergy has bee developed by SERCOS Iteratioal ad made available to the SERCOS users by meas of itegratio ito the SERCOS III specificatio. Classificatio of SERCOS Eergy SERCOS Eergy is a applicatio layer profile ad exteds the existig SERCOS profiles by addig aother profile that ca be implemeted i SERCOS compoets. I this coectio, SERCOS Eergy coects the process kow-how of the cotrols regardig the SERCOS commuicatio with the coected SERCOS compoets. This iteractio guaratees optimal eergy utilizatio. P EI [kw] 15 10 5 0 1-5 2 3-10 0 10 20 30 40 t [s] 4 5 6 7 50 60 70 80 Power cosumptio at the mai coectio of the machie versus time (itegral eergy) The cotrol reads out stadard parameters of each compoet that supports SERCOS Eergy via the SERCOS commuicatio bus receivig status iformatio ad detailed cosumptio values. This is all performed via the acyclic SERCOS commuicatio chael a stadard SERCOS commuicatio service that operates i parallel with the real-time commuicatios ad is therefore already a part of the automatio solutio. Depedig o the situatio, the cotrol is able Figure 2: Process power ad power cosumptio of a machie to issue commads to (source: ISW) put SERCOS Eergy compoets ito eergy-savig coditios. I this way, the permaet load ca be cosiderably reduced i stadstill durig short or log breaks (Figure 2). Apart from that, the process load ca be further reduced by the shut-dow of machie compoets ad/or their use i partial load operatio depedig o the situatio. 8 2010 by SERCOS INTERNATIONAL SERCOS ENERGY 5
SERCOS Eergy Applicatio scearios The SERCOS Eergy applicatio scearios have bee defied by the Istitute for Cotrol Egieerig of Machie Tools ad Maufacturig Uits (ISW) of Stuttgart Uiversity based o results of research ad feedback from maufacturers ad ed customers. I cotrast to the eergy profiles of other bus systems, the SERCOS Eergy profile is divided ito two levels. The upper level from the plat maagemet level to the machie cotrol provides iformatio o loger breaks ad failures (e.g., due to missig parts). The lower level from the machie cotrol to the load reacts at short otice (cotrol programs). I this way, you ca react to machie-specific failures ad curret processes i order to reduce eergy cosumptio. Withi the scope of the aalysis, the followig applicatio scearios for the plat maagemet level have bee defied for SERCOS Eergy: Short Breaks With short breaks that are usually ot loger tha oe hour, the machie usually is either brought ito a stadby operatio or completely switched off by the machie operator. The majority of these short breaks ca be scheduled, as i most compaies there are regular luch ad coffee breaks. Depedig o the break period, SERCOS Eergy puts compoets ito a optimal eergy cosumptio coditio. For short breaks, this may mea that re-iitializatio would cosume more eergy tha leavig the uit i a stadby coditio (ready for operatio). SERCOS Eergy provides mechaisms i order to be able to react to such boudary coditios ad helps i this way to dramatically reduce costs. Log Breaks Log breaks usually rage from several hours (e.g., overight) to several days or eve weeks (e.g., closig for Christmas). It is usually worth it to completely switch off some or eve all compoets i the productio system. As with short breaks, SERCOS Eergy puts compoets ito the optimal eergy cosumptio state. Uscheduled Breaks Uscheduled breaks ofte result from missig parts (e.g., due to delivery bottleecks) or operator itervetios. Uscheduled breaks caot be predicted. If the machie is put ito a coditio i which productio is stopped, it is first of all i a eergy savig coditio that ca quickly be exited agai. If the machie operator idetifies aother problem, SERCOS Eergy ca brig the machie ito other coditios i which eve more eergy ca be saved. If, o the other had, the ed of the failure is foreseeable, the machie ca also be put ito a coditio from which stadby operatio ca quickly be reached agai. 6 SERCOS ENERGY 2010 by SERCOS INTERNATIONAL
For the machie level, the followig applicatio scearios could be idetified for SERCOS Eergy: Partial Machie Operatio Especially with flexible productio, a machie provides more fuctioalities tha are required for every sigle productio step. With large systems, some machie compoets are oly eeded at a later poit i time i the productio process or ot at all i certai situatios. Based o its iformatio, SERCOS Eergy allows the cotrol to switch off machie compoets ad/or to throttle their eergy cosumptio if they are curretly ot required i the process. The compoet is the reactivated by the cotrol just i time ad makes its fuctioality available agai. The partial machie operatio available i SERCOS Eergy allows for the process-specific reductio of costs for the machie. Partial Load Operatio If there is a desired completio time/date ot requirig full-load operatio of the machie, you ca also save eergy ad protect the machie. SERCOS Eergy offers the possibility of reducig the eergy cosumptio of compoets i operatio, e.g., by field weakeig of drives. I this way, reduced eergy cosumptio is achieved. I additio, SERCOS Eergy provides geerally valid iterfaces i order to measure resource cosumptio, ot just electrical, but coolat ad compressed air for example, ad draw coclusios for optimizatio of productio. The measuremet ad visualizatio of cosumptio values are aother applicatio sceario for SERCOS Eergy. Measuremet ad Visualizatio Measuremet ad visualizatio combies the data recordig ad data preparatio. As metioed, apart from electrical parameters, other iformatio like coolat ad compressed air cosumptio may also be relevat for the cost optimizatio. SERCOS Eergy provides mechaisms for recordig the curret cosumptio, visualizig it o the HMI ad drawig coclusios for possible optimizatio, if applicable. The desigers of SERCOS Eergy tried to cosider all measurable parameters ad thus provide the characteristics i a flexible form. 2010 by SERCOS INTERNATIONAL SERCOS ENERGY 7
Advatages of SERCOS Eergy SERCOS Eergy offers the followig advatages: Durig istallatio: The use of SERCOS Eergy causes o additioal uit costs. Every fuctioality provided by SERCOS Eergy is already itegrated i the SERCOS compoets supportig SERCOS Eergy. Furthermore, additioal cablig is ot eeded for SERCOS Eergy compoets. Durig operatio: SERCOS Eergy reduces eergy cosumptio i three areas. First, the permaet load at stadstill is reduced; secod, the cosumptio depedig o the process is dyamically adjusted cosiderig the completio times/dates (partial load operatio); ad third, eergy is saved durig processig by switchig off compoets that are ot required at a particular time or poit i the process (partial machie operatio). User friedliess: Depedig o the cofiguratio, SERCOS Eergy ca idepedetly determie which coditio is optimal for maximum productivity at which poit i time. Maual selectio of eergy savig modes ad/or maual shut-dow of the machie is o loger ecessary. Opeess: The opeess of SERCOS gives differet maufacturers the possibility to develop ad sell products icorporatig the SERCOS Eergy profile. This quickly results i a broad product rage coverig all requiremets of SERCOS Eergy compoets. Iteroperability is guarateed by the certificatio of SERCOS compoets. Future-proof: SERCOS Eergy provides future-proof mechaisms that with growig experiece o the part of the users allow for a icreasigly efficiet use of SERCOS Eergy. This allows for higher eergy savigs i the future. Load maagemet: Due to the feedback of cosumptio data ad its iterpretatio, processig steps with high eergy cosumptio may be performed at times at which eergy costs are low. Cost reductio: By savig 50% of the power costs aloe i stadstill via SERCOS Eergy, the total eergy costs are reduced by approximately 10%. Gree image: The use of SERCOS Eergy sustaiably reduces CO 2 emissio. Thus, o the oe had the user ca support a evirometal strategy ad o the other had avoid the purchase of expesive CO 2 certificates. 8 SERCOS ENERGY 2010 by SERCOS INTERNATIONAL