Application Note - Energy Metering at a Medium Voltage Connection Point using a Voltage Transformer

Transcription

1 Applicatin Nte - Energy Metering at a Medium Vltage Cnnectin Pint using a Vltage Transfrmer This dcument describes the cnnectin and cnfiguratin f a Janitza meter at a medium vltage (MV) cnnectin pint t a SlarEdge device. This specific set-up may als be useful fr exprt limitatin applicatins. Medium vltage typically ranges frm (but is nt limited t) 6 kv t 33 kv. Use f the meter is nt limited t a cmmercial site's MV-side cnnectin pint. It can be used in lw-vltage applicatins as well. The meter cnnectin referred t in this applicatin nte is characterized by: Use f a vltage transfrmer t dwnscale high vltage. Direct measurement f the vltage f the cnnectin pint phases in 3-phase 3-cnductr systems using tw vltage transfrmers (Arn circuit) and tw current transfrmers. Revisin Histry Versin 1.1 (June 2018) Updated cnnectivity prcedure Versin 1.0 (March 2018) Initial release Cntents Intrductin 2 Supprted MV Meter 2 SlarEdge Device Firmware Versin 2 Meter Cnnectins 3 AC Pwer Cnnectin 3 RS485 Cmmunicatin Cnnectin 4 Pwer Supply Cnnectin 6 Device Cnfiguratin 6 Establishing Cnnectivity 6 1

2 Intrductin The meter can be cnnected t a SlarEdge inverter r Cntrl and Cmmunicatin Gateway (CCG). An example f such a cnnectin appears in the figure belw. Figure 1: MV meter cnnectin example The meter can be cnnected via the CCG (as shwn in this example), r directly t the inverter. The SlarEdge device reads the energy data frm the meter and frwards the data t the mnitring platfrm. In additin, exprt limitatin can be cnfigured. Supprted MV Meter The Janitza UMG 104 Pwer Analyzer is a three phase meter intended fr cmmercial use in medium-vltage and lwvltage grid envirnments, and can be used t implement exprt limitatin. Fr detailed infrmatin, refer t: SlarEdge Device Firmware Versin T use an MV meter cnnectin, the inverter cmmunicatin bard firmware (CPU) versin must be r later (but nt versin 4.xxxx). T check the inverter CPU versin: 1. Verify that the inverter has been activated using the activatin card supplied with the inverter. 2. T check the firmware versin f the CPU shrt press the LCD light buttn n the inverter until the screen belw is displayed: I D : # # # # # # # # # # I D : 7 F E 0 3 D S P 1 / 2 : / D S P 1 : C P U : x x C u n t r y : E S P 3. T upgrade inverters with earlier firmware versins, refer t 2

3 Meter Cnnectins Meter Cnnectins AC Pwer Cnnectin Fr detailed infrmatin n hw t cnnect the meter s AC side, refer t the installatin guide prvided with the meter. Site current transfrmers (CT) are cnnected t the meter CT inputs. Fr lwering the medium vltages t the perating range f the meter, vltage transfrmers (VT) are cnnected t the meter phase inputs. The fllwing figures illustrate CT and VT cnnectins. Figure 2: Cnnecting Current Transfrmers t the Janitza UMG 104 Figure 3: Cnnecting Vltage Transfrmers t the Janitza UMG 104 3

4 RS485 Cmmunicatin Cnnectin RS485 wiring specificatins: Cable type: Min. 3-wire shielded twisted pair (a shielded Ethernet cable (Cat5/5E STP) may be used) Wire crss-sectin area: mm²/ AWG (a CAT5 cable may be used) Maximum ndes: 32 Maximum distance between first and last devices: 1 km /3300 ft. If using a cable lnger than 10 m/33 ft in areas where there is a risk f induced vltage surges by lightning, it is recmmend t use external surge prtectin devices. Fr details refer t: If grunded metal cnduit are used fr ruting the cmmunicatin wires, a lightning prtectin device is nt required. If nt using surge prtectin, cnnect the grunding wire t the first inverter in the RS485 chain; make sure the grunding wire is nt in cntact with ther wires. Fr inverters with a Cnnectin Unit, cnnect the grunding wire t the grunding bus-bar in the Cnnectin Unit. T cnnect a cmmunicatin cable t the meter: 1. Lsen the screws f pins 485A and 485B n the meter, as shwn belw: 2. Insert the wire ends int the 485A and 485B pins. 3. Tighten the terminal screws. Figure 4: Meter t SlarEdge RS485 Cnnectin 4. Cnnect the ther end f the cable t the SlarEdge device as detailed in RS485 Cmmunicatin Cnnectin n page 4. Make sure t perfrm a "crss" RS485 cable cnnectin between: * Cnnect wire A n the meter t wire B n the SlarEdge device. * Cnnect wire B n the meter t wire A n the SlarEdge device. 5. If multiple meters are used, cmmissin each meter separately when nly ne meter is cnnected n the RS485 bus. Refer t Device Cnfiguratin n page 6. T cnnect the meter t a three phase inverter : An additinal RS485 prt (RS485-E) is available frm SlarEdge, allwing cnfiguratin f multiple RS485 buses fr cmmunicatins in large sites; Refer t expansin_kit_installatin_guide.pdf). 1. Turn the inverter ON/OFF switch t OFF. 2. Turn OFF the DC Safety Unit (if applicable) and the AC switch f the main circuit bard. 3. Open the inverter cver. 4

5 4. Remve the seal frm ne f the penings in cmmunicatin gland #2 at the bttm f the inverter, and insert the wire thrugh the pening. 5. Pull ut the 9-pin RS485 terminal blck cnnectr lcated n the cmmunicatin bard, as shwn belw: RS485 Cmmunicatin Cnnectin Figure 5: The RS485 terminal blck 6. Lsen the screws f pins A and B f the RS485 prt, as shwn belw: Inverter: use the RS485-1 prt r RS485-E if an RS485 Expansin Kit is cnnected Figure 6: RS485 terminal blck 7. Insert the wire ends frm the meter int the pins shwn abve: Cnnect the wire frm RS485 A in the meter t pin A. Cnnect the wire frm RS485 B in the meter t pin B. 8. Tighten the terminal blck screws. 9. Push the RS485 terminal blck firmly all the way int the cmmunicatin bard. 10. Terminate the inverter by switching a terminatin DIP-switch inside the inverter t ON. The switch is lcated n the cmmunicatin bard and is marked SW7. Figure 7: RS485 terminatin switch T cnnect the meter t a Cntrl and Cmmunicatin Gateway (CCG): 1. Pull ut the 3-pin RS485-2 terminal blck cnnectr. 5

6 Figure 8: Gateway RS485 cnnectins and DIP switches 2. Lsen the screws f terminals A, B and G. 3. Insert the wire ends frm the meter int the A and B pins shwn abve, in "crssed" fashin: Cnnect the wire frm RS485 A in the meter t pin B. Cnnect the wire frm RS485 B in the meter t pin A. 4. Tighten the terminal blck screws. 5. Push the RS485 terminal blck firmly int its prt. 6. Terminate the gateway by switching the SW2 terminatin DIP-switch t ON, as shwn in the figure abve. Pwer Supply Cnnectin The input pwer supply f the meter is specified n the meter s rating plate. Befre applying the pwer supply vltage, ensure that the vltage and frequency match the infrmatin prvided n the rating plate. The cnnectin cables fr the pwer supply vltage must be fused with a UL-listed fuse (6A type C), as depicted in the figure belw. Device Cnfiguratin Figure 9: Pwer Supply Cnnectin This sectin describes basic cnfiguratin f SlarEdge devices (inverter/ccg) fr using an MV meter. In additin, exprt limitatin may be required. Refer t Establishing Cnnectivity When first establishing cnnectivity between the SlarEdge device and the Janitza meter, the meter's Mdbus address must be synchrnized between the devices. Cnfigure the Janitza meter using the arrw keys adjacent t the screen. Fr detailed infrmatin, refer t the manual prvided with the prduct. 6

7 Establishing Cnnectivity Figure 10: Janitza meter screen and buttns T establish cnnectivity between the SlarEdge device and the Janitza UMG 104 Meter: 1. Switch the Janitza meter t Prgram mde: Simultaneusly press keys 1 and 2 fr arund ne secnd. The PRG symbl fr prgramming mde appears. The cntent f address 000 is displayed. 2. Access the memry address 200 t display the meter's Mdbus address. Set the address t "2". 3. Exit prgram mde: Simultaneusly press bth keys fr arund 1 secnd. The setting is saved and the meter returns t display mde. 4. Access the SlarEdge device, and enter the setup mde. a. Enter Setup mde by pressing the Enter (3) buttn fr at least five secnds. The fllwing message is displayed: P l e a s e P a s s w r d * * * * * * * * e n t e r b. Use the three right-mst buttns (Up-1, Dwn-2 and Enter-3) t type in the default passwrd: Cmmunicatin èrs485-x Cnf. The RS485-X screen is displayed: D e v i c e T y p e < S E > P r t c l < M > D e v i c e I D < 1 > S l a v e D e t e c t < # > C l u s t e r S L V D e t e c t L n g S l a v e D e t e c t < # > S l a v e L i s t < # > M u l t i - I n v. S e t 6. Select Device TypeèMulti Devices. 7. Select Meter 1. The meter cnfiguratin screen is displayed: D e v i c e T y p e < M T R > P r t c l < J N > D e v i c e I D < 2 > C T R a t i n g < 0 > S e c n d a r y C T < 5 > V T R a t i n g < > S e c n d a r y V T < > M e t e r F u n c. < N n e > M e t e r C m m i s s i n T p l g y < W y e > 8. Select Device ID, and set the ID t 2 (the same Mdbus address cnfigured earlier in the Janitza meter). 9. Select Meter Cmmissin t display the fllwing menu: S e t S e r i a l C n f S e t M e t e r I D Make sure that the Device ID is always synchrnized with the Mdbus address set in the Janitza meter. If the values are different, the cnnectin between the devices will be lst. In the event that yu need t mdify the address, use the Set Meter ID functin in the SlarEdge device. This functin mdifies the address setting simultaneusly in the Janitza meter and the SlarEdge device, thus preserving the cnnectin. See the prcedure, T mdify the Mdbus address f a cnnected meter. 7

8 10. Select Set Serial Cnf t aut-cnfigure the meter's serial interface baud rate t Wait fr the message "Applied" t appear. T check the setting, switch the Janitza meter t Prgram mde, and make sure that the value at address 202 is set t '0' (9600 baud). If the value is nt set t '0', then mdify the value manually. T mdify the Mdbus address f a cnnected Janitza meter: 1. Perfrm steps 1 t 7 f the prcedure,t establish cnnectivity between the SlarEdge device and the Janitza UMG 104 Meter. 2. Select Meter Cmmissin, and in the Meter Cmmissin menu, select Set Meter ID. 3. The message "Make sure single device is cnnected. Cntinue?" is displayed. Make sure that nly ne Mdbus device is cnnected t the SlarEdge device, and respnd YES. 4. Enter the existing Meter ID, and press <Enter>. 5. Enter the new Meter ID, and press <Enter>. Wait while the meter ID is mdified, and the value in the SlarEdge device is mdified. The message "Applied" is displayed. T cnfigure the SlarEdge device fr using Janitza meters: 1. Access the SlarEdge device, and enter the setup mde. : a. Enter Setup mde by pressing the Enter (3) buttn fr at least five secnds. The fllwing message is displayed: P l e a s e P a s s w r d * * * * * * * * e n t e r b. Use the three right-mst buttns (Up-1, Dwn-2 and Enter-3) t type in the default passwrd: Cmmunicatin èrs485-x Cnf. The RS485-X screen is displayed: D e v i c e T y p e < S E > P r t c l < M > D e v i c e I D < 1 > S l a v e D e t e c t < # > C l u s t e r S L V D e t e c t L n g S l a v e D e t e c t < # > S l a v e L i s t < # > M u l t i - I n v. S e t 3. Select Device TypeèMulti Devices. 4. Select Meter 1. The meter cnfiguratin screen is displayed: D e v i c e T y p e < M T R > P r t c l < J N > D e v i c e I D < 2 > C T R a t i n g < 0 > S e c n d a r y C T < 5 > V T R a t i n g < > S e c n d a r y V T < > M e t e r F u n c. < N n e > M e t e r C m m i s s i n T p l g y < W y e > 5. Cnfigure the fllwing settings: Device/Meter Type: Revenue Meter Meter Prtcl: Janitza Device Id: 2 (as was set in the previus prcedure) CT Rating: <200> accrding t the primary MV CT Secndary Rating: <5> accrding t the secndary MV CT VT Rating : <11000> accrding t the primary ptential transfrmer Secndary VT: <110> accrding t the secndary ptential transfrmer Meter Func.: <Exprt+Imprt> 8

9 Establishing Cnnectivity CT Rating and Secndary CT shuld reflect the dwnscaling rati f the existing current transfrmer rati installed at the site: Dwnscale Rati = (CT Rating) / (Secndary CT). Fr example, using the values abve - current dwnscale rati = 200/5 = 40 VT Rating and Secndary VT shuld reflect the dwnscaling rati f the existing ptential transfrmer rati installed at the site: Dwnscale Rati = (VT Rating) / (Secndary VT). Fr example, using the values abve - ptential dwnscale rati = 11000/110 = 100 T verify meter cnnectin: 1. Shrt-press the LCD light buttn (n the inverter) r the Enter buttn (inside the inverter) until the Cmmunicatin status screen is displayed as shwn belw. This screen shws the number f external devices that cmmunicate n each prt, the device type, and the prtcl t which each prt was cnfigured. 2. Verify that the setting f the relevant RS485 prt is crrect and that the prt is cmmunicating with the meter. Fr example, if the meter is cnnected t the RS485-1 prt, the Cmmunicatin status screen shuld display the fllwing: w w w w w w w D e v P r t # # R S < M T R > < J N > < 1 > R S < > < - - > < - - > Z i g B e e < > < - - > < - - > Dev: the type f device cnfigured t this prt. MTR indicates a meter. Prt: the cmmunicatin prtcl ## = 1: Indicates that the cnnectin t the meter is successful. 3. Cntinue pressing the Enter buttn r the LIGHT buttn using shrt presses until reaching the meter status screen shwing the Energy [Wh] ttal. If there is mre than ne meter/ functin, there is a status screen fr each ne. The fllwing is an example f an Exprt meter: E x p r t M e t e r S t a t u s : < O K / E r r r # > P w e r [ W ] : E n e r g y [ W h ] : x x x x x. x X X X X X. X Status: Displays OK if the meter is cmmunicating with the inverter. <Errr message>: If an internal meter errr ccurs, it will be displayed here. Refer t Trubleshting the Janitza Meter Cnnectin n page 10. Energy [Wh]: Displays the accumulated lifetime energy f the meter. If the SlarEdge device is cnnected t the mnitring platfrm, this value will als be displayed in the mnitring platfrm. T display the meter serial number: 1. Enter Setup mde and select Infrmatin. The fllwing screen is displayed: V e r s i n s E r r r W a r n i n g L g H a r d w a r e l g I D s 2. Select Hardware IDs. The fllwing is displayed shwing the ID f the inverter and any meter cnnected t it: I D F F F F 4 E R G M :

10 Appendix A: Trubleshting the Janitza Meter Cnnectin Appendix A: Trubleshting the Janitza Meter Cnnectin This sectin describes hw t trublesht installatin and perfrmance errrs. Cmmunicatin Status Screen Trubleshting The Cmmunicatin status screen shuld display the fllwing: w w w w w w w w D e v P r t # # R S < M T R > < J N > < 1 > R S < > < - - > < - - > Z i g B e e < > < - - > < - - > Device Type r Prtcl are cnfigured incrrectly 1. Select Cmmunicatin è RS485-x Cnf è Device Type è Revenue Meter. 2. Select Cmmunicatin è RS485-x Cnf è Prtcl è Janitza. 3. Check that the Device ID under Cmmunicatin è RS485-X Cnf è Device ID is set t Select a meter type: Revenue Meter è Meter Func. è Exprt+Imprt / Exprt / Imprt / Cnsumptin / Site Prductin / Inv. Prductin. Number f devices is nt displayed If <--> is displayed under the ## clumn in the Cmmunicatin status screen, the meter is nt cmmunicating with the inverter. Check the fllwing: Ensure that the meter cnfiguratin in the inverter is set as described in the previus sectin. Check that the meter's settings are cnfigured as specified in the meter's User's Manual. Check that the wiring between the meter and the RS485 terminal blck n the cmmunicatin bard is crrect and well cnnected. Use a Vltmeter t measure the vltage n the meter's 10-pin terminal blck. The L1 L2 line t line vltage shuld be 400 Vac ± 20%. Meter Status Screen Trubleshting E x p r t M e t e r S t a t u s : < O K / E r r r # > P w e r [ W ] : E n e r g y [ W h ] : <OK> is nt displayed x x x x x. x X X X X X. X If <OK> is nt displayed in the Status line f the status screen shwn abve, the meter is nt cmmunicating with the inverter. Check the fllwing: There are n lse cnnectins at the inverter cmmunicatin bard and at the meter. The wiring between the black 4-pin terminal blck n the meter and the RS485 terminal blck n the cmmunicatin bard is crrect. An errr message is displayed If Cmm. Errr is displayed in the meter status screen, verify prper cnnectin f: The RS485 cables and cnnectrs The AC cnnectin f the meter If the message Errr cde 3x6E r Errr 185 Meter Cmm. Errr is displayed, cntact SlarEdge supprt. Energy [Wh] value is nt advancing If the Energy [Wh] value displays a steady value althugh the the site is exprting/ imprting pwer, check the fllwing: There are n lse cnnectins at the inverter cnnectrs and at the meter, specifically the AC wiring n the meter 10-pin cnnectr. The current transfrmers are cnnected t the meter as illustrated in Figure 2. 10

11 Appendix B: External Lightning Prtectin Cnnectin Prtectin devices are mst ften installed frm each data line t the lcal earth grund, and shuld be selected t begin cnducting current at a vltage as clse t the system's nrmal cmmunicatin level as pssible, but never lwer. Fr RS485 cmmunicatin lines, the selected vltage rating is typically 6-8 V. Transient suppressrs shuld be installed as clse as pssible t the prt that is being prtected, and the user must prvide an extremely lw impedance cnnectin t the lcal earth grund f the SlarEdge device. This grund cnnectin is crucial fr prper suppressin device peratin. The grund cnnectin shuld be made using a heavy gauge wire and kept as shrt as pssible. If the cable between the SlarEdge device and the prtectin device must be lnger than 1m/3.3 ft., a cpper strap r a braided cable intended fr grunding purpses must be used fr the prtectin device t be effective. In additin t the high frequency nature f transients, extremely high current may flw. A prtective device with surge discharge ratings f In: 10kA 8/20μs and Imax: 20kA 8/20μs is recmmended. Varius lightning prtectin devices are available fr RS485 cmmunicatin lines. Appendix B: External Lightning Prtectin Cnnectin The diagram belw shws a cnnectin example using the Raycap RayDat RS 485 data prtcl prtectin device. A detailed specificatin can be fund at: pages Figure 11: Prtectin cnnectin 11