Power Monitoring and Control for Electric Home Appliances Based on Power Line Communication

Transcription

1 I²MTC 2008 IEEE Intenational Instumentation and Measuement Technology Confeence Victoia, Vancouve Island, Canada, May 12 15, 2008 Powe Monitoing and Contol fo Electic Home Appliances Based on Powe Line Communication Chia-Hung Lien*, Hsien-Chung Chen**, Ying-Wen Bai**, and Ming-Bo Lin*** * Depatment of Compute science and Infomation Engineeing, Lee-Ming Institute of Technology, Taipei, Taiwan, 243, R.O.C. **Depatment of Electonic Engineeing, Fu Jen Catholic Univesity, Taipei, Taiwan, 242, R.O.C ***Depatment of Electonic Engineeing, National Taiwan Univesity of Science and Technology, Taipei, Taiwan, 106, R.O.C. lianhome@seed.net.tw Abstact Home powe consumption tends to gow in popotion to the incease in the numbe of lage-sized electic home appliances. An embedded system without any new additional wiing has been developed fo home powe management. By using Powe Line Communication (PLC) technology, electic home appliances can be contolled and monitoed though domestic powe lines. We descibe a PPCOM (PLC Powe-Contolled Outlet Module) which integates the multiple AC powe sockets, the powe measuing module, the PLC module and a micocontolle into a powe outlet to switch the powe of the sockets on/off and to measue the powe consumption of plugged-in electic home appliances. We have also designed an embedded home seve which suppots the Web page use inteface, thus allowing the use to easily contol and monito the electic home appliances by means of the Intenet. In addition, the field expeiments epoted have demonstated that ou design can be pactically implemented and povides adequate esults. Keywods Remote Measuement, Remote Contol, Powe Management, Powe Line Communication. I. INTRODUCTION Powe monitoing and contol though home netwoks is becoming impotant fo electic home appliances. Togethe with the constuction of access netwoks, seveal standads fo wied home netwoks have been poposed and developed [1]. RS-232 hadwae is an inteface of easy design and in common use in today s industial envionment. Howeve, RS-232 communications have some dawbacks in that floo envionments often geneate not only electical noise but also tansients that can cause eos in tansmission and damage to the inteface components. The othe dawbacks of RS-232 ae its point-to-point chaacteistic and a distance limitation of 15 m [2]. A typical IP-based device can emotely contol powe switches of electic home appliances. By using this device one can connect the Intenet with an RJ45 and can be connected to any compute [3]. Radio fequency (RF) technology is moe flexible and allows the use to link electic home appliances distibuted thoughout the house [4]. RF can be categoized as a naow band o spead spectum. Naow band technology equies a clea channel uninteupted by othe digital appliances. Since each tansmitte/eceive appliance tansmits using its own fequency, it is unlikely to intefee with othe RF appliances connected to the home netwok. Howeve, if the wieless appliance is moved to anothe location in the house, it is possible that intefeence may occu. This limitation makes the use of this technology unsuitable fo a numbe of home netwok applications [5]. Bluetooth technology povides a univesal bidge to existing data netwoks, a peipheal inteface and a mechanism to fom small pivate ad hoc goupings of connected devices away fom fixed netwok infastuctues. Designed to opeate in a noisy adio fequency envionment such as a home, the Bluetooth technology uses both a fast acknowledgement and a fequency-hopping scheme to make the link obust. Bluetooth technology, theefoe, can eplace the cumbesome cables used today to connect the PDA to any othe digital device [6]. To implement home powe management, both netwoked electic home appliances with contol/monitoing capabilities and home netwoks without new wiing ae indispensable [7]. Powe line communication (PLC) is used to utilize a domestic powe line as a communication cable. Home netwok devices ae categoized as wied devices. The PLC povides high bit-ate data sevices by using the powe gid esiding in the vast infastuctue aleady in place fo powe distibution, which means that the potential effect of the sevice could be much highe than that of any othe wie line altenative. Because PLC is a home netwok medium without any new additional wiing, it is easily installed in an existing esidence [8]. In this pape we descibe an embedded system using PLC technology which has been developed to emotely monito/contol the powe of electic home appliances fo home powe management. A home seve is a hadwae device connecting a home netwok with a wide aea netwok (WAN) o the Intenet. The esidential gateway povides pot tanslation (NAT), allowing all the computes in a small netwok to shae the same IP addess and Intenet connection [9]. The home seve sits between the modem and the intenal netwok, o, as an altenate, a DSL o cable modem may be integated into the home seve. A home seve often combines the functions of IP oute, fiewall, multi-pot Ethenet switch and Wi-Fi access point. Home seves that include outing capabilities ae conveged devices and sometimes efeed to as home outes o boadband outes with boadband in this case efeing not to the oute function but to the Intenet access function. Home seves ae unde standadization by the Home Gateway Initiative [10] /08/$ IEEE 2179

2 Fig. 1 shows an oveview of the embedded system which consists of thee pats: the PPCOM (PLC Powe-Contolled Outlet Module), the embedded home seve and the emote contol. Fo easy setup the entie hadwae pototype of the PPCOM is now implemented in a box (18.5 cm 15.5 cm 3.8 cm). Any electic home appliance plugged into the socket of a PPCOM can be contolled and monitoed without making any additional setting. The PLC and the asymmetic Digital Subscibe Line (ADSL) which has been selected fo a wide aea netwok have also been selected fo the home netwok. By combining PLC and Ethenet technologies, PPCOM can connect to the embedded home seve without any new additional wie lines. The embedded home seve connects to the Intenet by means of the ADSL. Thus the use can manage electic home appliances and emotely monito the powe consumption status of the electic home appliances by means of the emote Web bowse. The emote Web bowse with a GUI allows the use to easily contol/monito the powe status of electic home appliances. We have used Solid State Relays (SSR) to switch each socket on/off fo an electic home appliance. SSR have been used to eplace mechanical elays because of thei many advantages, including miniatuized configuation, elimination of contact bounce, low-enegy consumption, deceased electical noise and compatibility with digital cicuit and high-speed switching pefomance. These SSR also povide isolation between a contol cicuit and a switched cicuit. To show the opeational status of the electic home appliances, and to contol the powe on/off we use the Powe Measuing Module, which is a measue cicuit containing fou pats: two cuent tansfomes (CT), an electical powe detecto, a multiplexe and a powe load micopocesso. The two CT ae installed in the AC powe outlet, as shown in Fig. 2. The load cuent of each socket is measued by the CT. By using the Hall Effect the chage caies in the CT become deflected by the magnetic field and give ise to an electic field which is pependicula to both the cuent and the magnetic field, as the load cuent changes the output voltage signal. Fig. 1. The block diagam of the embedded system without any new additional wiing. This pape is oganized as follows. Section II intoduces the PPCOM, Section III descibes the embedded home seve, Section 4 summaizes the evaluation esults, and the final Section pesents ou conclusions. II. PPCOM DESIGN The PPCOM combines with the multiple AC powe sockets. In the PPCOM a simple plug-in MCU pefoms the powe on/off of the sockets and pocesses measued data. The PPCOM also includes a powe measuing cicuit to measue the powe consumption of each electic home appliance. The cicuit diagam of the PPCOM is shown in Fig. 2. The PLC Module uses state-of-the-at CMOS design techniques to delive the highe pefomance and flexibility. This highly integated design combines the Media Access Contol laye (MAC) and the Physical Laye (PHY) in a single chip. The PLC Module is a convete that connects electic home appliances to the Intenet based on UDP potocol, thus allowing the use to contol and monito electic home appliances ove the Intenet. Fig. 2. Cicuit diagam of the PPCOM. The electical powe detecto uses a high-accuacy electical powe measuement IC with a seial inteface and a pulse output. The electical powe detecto is compised of two ADCs, a efeence cicuit and the signal pocessing necessay fo the calculation of eal (active) powe. Cicuity is povided to null out vaious system eos including gain, phase and offset eos. Additional cicuity povides wavefom sampling, pogammable inteupts and powe line monitoing [11]. The socket voltage is connected to the electical powe detecto though the inteface cicuit which includes a filte. The socket cuent is conveted fom a cuent to a voltage by a CT. The electical powe multiplies the two voltage signals with the cuent signal and accumulates the esults in the egiste. The electical powe detecto measues the powe consumption of each socket continuously. The MCU is used to ead the egiste of the electical powe detecto cyclically though the communication pot. Moeove, the MCU waits fo the command fom the embedded home 2180

3 seve. If thee ae no contol commands, the MCU stoes the cuent powe status. If the MCU has eceived a command, it checks to see whethe o not the command is fo the oom contolled by the PPCOM. If the command is fo that oom, the MCU tuns the powe on/off o sends powe data accoding to the command. If the command is not fo any oom contolled by the PPCOM, the command is boadcast ove the PLC netwok. Fig. 3 shows the contol flow chat of the PPCOM. application sevices fo PPCOM with netwok access technique using HTML and JavaScipt. We have also designed a Monito AP which suppots the Gaphic Use Inteface (GUI), so the use can easily configue the embedded home seve status. We built the Monito AP to monito the socket status and the powe consumption. The use can use the columns of PPCOM numbes and socket numbes to select a specific powe socket. Next, the IP of this PPCOM, the status of the powe socket, watt consumption, voltage and cuent value will be shown. The on/off contol of this powe socket can be done diectly, as shown in Fig. 5. The use can use the columns of the PPCOM Numbe and the Socket Numbe to select a specific powe socket. Afte this selection, the IP of this PPCOM, the status of powe socket, the powe consumption, the voltage and the cuent value will be shown; the on/off contol of this powe socket can be done diectly. Fig. 3. The contol flow chat of the PPCOM. III. EMBEDDED HOME SERVER The embedded home seve is a centalized contolle and human inteface fo an in-house system. It also povides a simple Web bowse fo infomation and guidance fom the Intenet. Application pogams ae used to contol appliances in a house. Fig. 4 shows the block diagam of the embedded home seve. Fig. 5. Monito AP. Fig. 4. Block diagam of the embedded home seve. Intenet technologies such as TCP/IP, HTML, JavaScipt, Web Seve and Ciphe Secuity ae poted into the embedded home seve which is contolled and monitoed with HTML inteface fom both in-house and out-of-house via the Intenet. Popety and status of appliances ae expessed with thei stuctue by HTML and JavaScipt, whose desciption capability is excellent. Application sevice povides can monito/contol appliances emotely and can develop vaious We use the PLC to eceive/tansmit between the embedded home seve and the PPCOM. The embedded home seve offes an automatic system fo powe monitoing and contol. It also collects infomation to poduce an analysis of all powe consumption including the daily, weekly and monthly electicity consumption of individual electic home appliances and the total consumption of the home. Fig. 6 shows the contol flow chat of the embedded home seve. If thee ae no contol messages, the Web page displays the cuent powe status. If the system has eceived a message, it checks the command fomat fist. If the message is coect, the embedded home seve sends the message to the PPCOM to tun the powe on/off and waits fo an OK message fom the PPCOM. The embedded home seve sends the most ecent command message evey thee seconds until the embedded home seve has eceived an OK message to guaantee that the PPCOM will wok coectly. Ou design also suppots the Gaphic Use Inteface (GUI) to let the use easily monito and contol the powe on/off of each electic home appliance. 2181

4 Fig. 7. Home Page fo emote monitoing and contol on home seve. Fig. 6. The contol flow chat of the embedded home seve. The Web bowse is installed in a PC o a Notebook connected to the Intenet. It can contol electical home appliances when the use is outdoos. The stuctue of the netwok connection of the emote contol by Intenet is a Host-Client stuctue. The client-installed Web bowse sets IP addess and PORT, sends a equest to the PPCOM, ceates a link and stats to link both client and PPCOM. The emote use can access a PPCOM fom the Intenet connection. By means of the Intenet the use can use a Web bowse with a GUI to contol and monito the powe consumption of the electic home appliances. The emote contol home page displays not only the powe consumption but also the eal-time voltage and cuent of all PPCOMs connected to the embedded home seve. The accumulated enegy can be used to calculate the total cost stating fom the launch time, as shown in Fig. 8. IV. IMPLEMENTATION RESULTS The main goal is to be able to monito and contol the home powe status anywhee wheneve needed. In ou design a web seve is installed on the embedded home seve to allow any device with a Web bowse to connect to the embedded home seve, typically, fom outside the house. The emote contol home page povides the use with a way when connected to the Intenet to monito and contol the home powe status by means of any Web bowse. The use can equest the embedded home seve to monito and contol the electic home appliances, as shown in Fig. 7. Ou design povides thee pages of home page fo emote monitoing and contol. The fist page is the setup page, shown Fig. 7. This page lists the status of evey powe socket on the PPCOM connected to home seve, namely on/off, powe consumption, voltage and cuent value. This page can also contol the on/off of each powe socket, the setting of the time and the fequency of automatic on/off (once a week o once a day) and calculate the consumed powe and fee fo each powe socket. Fig. 8. Use initiates equests to monito and contol electic home appliances by means of a Web bowse. The emote contol home page suppots up to 12 metes of eal-time values. Each mete has the ability to display all PPCOM values. Selecting diffeent items fom the selection dialog aea displays the selected item value, as shown in Fig. 9. Fig. 9. Real-time monitoing of powe consumption, voltage and cuent of all PPCOMs. 2182

5 To validate thei accuacy we have compaed the esults of ou method with the mete measuement esults. The electic home appliance used fo the expeiment was a 40" LCD TV with a full HD 1,920 x 1080 pixels 16:9 sceen fomat display esolution. The powe of the LCD TV was measued by a powe mete with both one week measuement intevals and a one-second esolution. Fig. 10 shows the measuement esults obtained by use of ou PPCOM and those obtained by use of a powe mete. Afte conducting an expeiment fo one week, we found that thee was an eo of only about 8.2% between the estimated value and the measuement value. Fig. 10. Compaison of the measuements obtained by ou system s design and by the powe mete. The final implementation of the PPCOM is shown in Fig. 11. The whole hadwae pototype cicuit of the PPCOM is now implemented on a 16.5 cm 12.5 cm pinted cicuit boad (excluding the SSR and sockets). In the pototype of ou design the embedded home seve was built with an embedded platfom which had an 800-MHz Intel Pocesso, 512-MB RAM and a 60-GB had disk. The embedded home seve an Micosoft Windows Embedded XP Sevice Pack 2 as its opeating system and deployed the Apache as its Web seve which is designed by softwae using Visual C++ Studio [12]. (b) Fig. 11. Outside (a) and inside (b) of the PPCOM By using PLC the PPCOM enables the home netwok use to connect a wide ange of electic home appliances easily, theeby eliminating the need of additional cabling to connect individual devices. The use needs only to follow thee steps to finish installing the emote-contollable powe outlet system indoos. 1. Replace the conventional outlet with a PPCOM to povide AC powe fo the electic home appliances. 2. Connect the embedded home seve to the PPCOM by means of the PLC seach. 3. Then the use can display and contol the electic home appliance s powe on/off by using the Web bowse. We also conside the powe consumption of the PPCOM itself. Its aveage powe consumption is measued as shown in Table 1. The point to obseve is that the PLC Module and the electical powe detecto consume maximal 22 ma and 24 ma sepaately while communicating. The total powe consumption of a PPCOM is about 1 W and inceases when the numbe of sockets of the PPCOM inceases. Item PLC Module Bluetooth Module MCU and Essential Cicuit Table 1. Compaison of home powe management designs. Aveage Cuent (ma) Opeation Voltage (V) Aveage powe Consumption (W) Total (a) An additional advantage of the Powe Measuing Module is that it detects the status and measues the cuent consumption of an electic home appliance s powe use in addition to contolling the on/off state of the sockets. In this expeiment 2183

6 the Powe Measuing Module detects and measues an electic home appliance s powe consumption anging fom 1 W to 1200 W. We can extend the ange to detect and measue lowe and highe powe consumption fom 0.47 W to 2500 W by changing the CT which can incease its volume by half. In addition we have compaed ou design with othe home powe management designs. The esult of ou expeiment demonstates that as ou design has moe integated functions it is supeio to othe designs. The details of ou compaison ae shown in Table 2. Table 2. Compaison of home powe management designs. Method 1 [1] Method 2 [2] Method 3 [3] Ou design RF PLC Ethenet PLC Home seve X PC PC Embedded home seve Seve powe consumption X 156 Watts 156 Watts 17.3 Watts* Length 10 m Line Line Line Setup Communication Complicated Complicated Easy Easy Scale out Limited Limited Limited Unlimited Each socket contolling Each socket monitoing Total powe monitoing Remote contol softwae Minimum powe detection X X X Yes X X X Yes X Yes X Yes Local contol X Specific softwae About 5 Watts Specific softwae About 5 Watts Web bowse About 0.1 Watt The embedded system and the key components fo home powe management have been developed, and in ode to utilize emote contol, the PLC technologies fo powe management have been integated. The poposed PPCOM is designed fo emote monitoing and contolling of diffeent electic home appliances connected ove a PLC netwok in a home envionment. The embedded home seve connects to the Intenet by the ADSL. Thus the use can manage electic home appliances and emotely monito thei powe consumption status by means of a emote Web bowse. REFERENCES [1] T. Shibata, K. Ogawa, H. Takemua and Y. Hatayama, The new achitectue that ealizes seamless connectivity and coopeative contol fo home netwok systems, in Poc. ICCE 05, pp , [2] Chia-Hung Lien, Chi-Hsiung Lin, Ying-Wen Bai, Ming-Fong Liu, and Ming-Bo Lin, Remotely Contollable Outlet System fo Home Powe Management, in Poc. ISCE '06, pp.1-6, [3] IEEE P802.11, The Woking Goup fo Wieless LANs, etieved Septembe 20, 2003, Available: [4] IEEE , etieved August 28, 2007, Available: ieee802.og/15/pub/tg1.html. [5] Masahio Inoue, Toshiyasu Higuma, Yoshiaki Ito, Noiyuki Kushio and Hitoshi Kubota, Netwok Achitectue fo Home Enegy Management System, IEEE Tans. Consume Electon., vol. 49, no. 3, pp , Aug [6] H. Ikebe, K. Ogawa, H. Takenua and Y. Hatayama, New achitectue of ealizing seamless connectivity and coopeative contol fo home netwok systems, in Poc. ISCAS 05, pp , [7] C. Bae, J. Yoo, K. Kang, Y. Choe, and J. Lee, Home seve fo home digital sevice envionments, Digest of Technical Papes in Intenational Confeence on Consume Electonics, pp , June [8] C. Bae, J. Lee, and C. Kim, State of the at and the developmentdiection of home seve technology, Koea Infomation Pocessing Society Review, vol. 8, no. 1, pp , Jan [9] Song Yean Cho, Famewok fo the Composition and Inteopeation of the Home Appliances based on Heteogeneous Middlewae in Residential Netwoks, IEEE Tansaction on Consume Electonics, 2002 [10] Noiyuki Kushio, Koichi Sato, Noiyuki Komiya, Mananoi Nakata, Masahio Inoue, Hideo Tsubota, Agent Based Gaphical Use Inteface Achitectue fo Consume Poducts, IEEE Tansaction on Consume Electonics, 1996 [11] Powe Mete IC, Available: /en/poducts /po/techs/t14.html. [12] Embedded XP, Available: embedded/eval/ xpe/ default.mspx. *The powe consumption can be educed to below 1 Watt by including the embedded home seve in the PPCOM. V. CONCLUSION By utilizing the PLC technique we have built an embedded emote electic powe monito/contol system which is vey easy to install and does not need additional wiing. This system enables the use to contol the on/off and the powe consumption emotely without botheing with exta wiing. Thus the system is vey convenient and can be used at once afte just plugging it in. 2184