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New Capacitor Analysis and Maintenance Process at Centerpoint Energy

New Capacitor Analysis and Maintenance Process at Centerpoint Energy. Presented at SWEDE Conference 2005 by Richard Moffatt. Why do we have Capacitors? (Power Factor = KW / KVA). KVARS. KVA. KW’s. Process Improvement Recommendation. Goal: Reduce Capacitor Maintenance Expense

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New Capacitor Analysis and Maintenance Process at Centerpoint Energy

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  1. New Capacitor Analysis and Maintenance Process at Centerpoint Energy Presented at SWEDE Conference 2005 by Richard Moffatt

  2. Why do we have Capacitors?(Power Factor = KW / KVA) KVARS KVA KW’s

  3. Process Improvement Recommendation • Goal: Reduce Capacitor Maintenance Expense • Send capacitor crews directly to circuits with problem capacitors, and thus eliminate their random search for failed capacitors (Time, temp, fixed banks). • Develop program (CAPSURE) to detect capacitor banks that are switching but experiencing a partial failure on 1 or 2 phases. Uses load survey data for circuits (KW & KVAR) on 15 minute intervals. • Produce “Bank Shot Report” • Produce “Low Power Factor Report”

  4. Bank Shot Report • Identifies KVAR changes greater than the minimum threshold value based on the smallest cap on circuit. • Looks for single phase or two phase failures. • Two tests: • Magnitude of KVAR change (15 min intervals) compensated by KW load change. • KVA phase angle change. • In most cases, can infer the probable bank size based on the magnitude of the change in KVARS. • Pull in caps on circuit from Capacitor Database. • Pull in PF at peak for identified circuits.

  5. Bank Shot Report 9-1-04 Left Half of Spreadsheet Wednesday Sept 1, 2004 8/30/2004 8/31/2004 9/1/2004 CKT PF Peak Peak Peak KW Last KW Last KW Last KW This KW This KW This KVAR Last KVAR Last KVAR Last KVAR This KVAR This KVAR This CKT TIME PF PF PF A B C A B C A B C A B C This Read AD 04 1:16 98.8 99.8 99.9 100.0 1389 1501 1529 1318 1413 1441 172 207 -3 309 348 -3 AD 04 9:31 -99.8 99.8 99.9 100.0 1343 1188 1508 1375 1252 1557 292 204 -3 -66 -182 -3 AD 04 12:16 -99.6 99.8 99.9 100.0 1811 1821 1986 1884 1853 2078 137 81 -3 -217 -291 -3 AD 04 21:16 99.9 99.8 99.9 100.0 2239 2359 2500 2187 2370 2450 -90 -87 -3 91 137 -3 AD 04 21:46 99 99.8 99.9 100.0 2071 2155 2370 1965 2197 2299 53 56 -3 397 524 -3 AD 09 12:01 -98.4 99.5 99.9 99.9 1316 1501 1785 1305 1453 1749 -33 18 140 -434 -471 82 AD 09 21:46 97.2 99.5 99.9 99.9 1543 1981 2318 1601 1917 2207 -70 61 583 356 440 583 AF 01 1:01 90.8 99.4 99.9 99.8 1749 1770 1975 1749 1706 1917 799 356 435 831 767 873 AF 01 9:46 96.9 99.4 99.9 99.8 1680 1633 1654 1691 1669 1865 789 673 757 773 251 314 AF 02 8:01 -99.4 -99.7 -100.0 -100.0 1195 1158 1263 1158 1200 1242 282 -128 -139 293 -323 -350 AF 06 12:01 -88.6 -99.6 -98.0 -97.9 1369 1369 1332 1495 1374 1364 -666 -476 -761 -766 -672 -777 AF 06 23:01 -97.7 -99.6 -98.0 -97.9 1727 1548 1532 1590 1580 1559 -492 -381 -487 -360 -170 -497 AF 07 13:01 99.1 98.9 99.3 99.6 1833 1369 1506 1986 1411 1696 525 124 277 330 161 203 AF 07 13:16 97.7 98.9 99.3 99.6 1986 1411 1696 1938 1422 1553 330 161 203 609 145 314 AF 10 10:01 99.9 100.0 -100.0 -99.8 905 1110 1300 915 1153 1342 61 525 314 -371 546 -65 AN 04 22:46 96.5 96.2 96.9 96.7 1754 1800 1814 1754 1730 1765 738 179 292 703 446 281 AN 05 14:46 -99.7 100.0 -100.0 -99.9 1983 2053 1825 2043 2190 1772 25 60 -379 -129 -76 -224 AN 05 22:16 -99.3 100.0 -100.0 -99.9 1768 1905 1519 1828 1825 1501 -224 -192 -312 -31 -59 -509 AN 06 2:31 95.3 96.4 98.8 97.6 2128 2054 2152 2120 2054 2088 809 206 253 786 580 625 AN 06 9:31 98.5 96.4 98.8 97.6 1956 2025 2041 2152 2210 2283 715 564 596 762 208 211 AN 07 19:01 -99.4 98.9 99.3 99.7 2046 1690 1790 2088 1732 1790 132 74 8 -294 -358 21 AN 07 22:46 -98.9 98.9 99.3 99.7 1577 1242 1279 1598 1242 1297 -645 -648 -331 -149 -178 -286 AN 09 0:31 97.8 99.2 99.4 99.3 1466 1642 1459 1318 1533 1389 496 88 -178 436 352 113 AN 09 9:31 -99.9 99.2 99.4 99.3 1575 1628 1621 1617 1645 1673 267 148 -41 302 -150 -319 AN 10 8:01 95 99.2 99.4 99.6 1155 1121 1466 1216 1189 1513 612 541 585 643 66 585 AN 10 22:01 99.9 99.2 99.4 99.6 1202 1076 1825 1247 1044 1772 174 -598 211 177 -144 174 AR 41 4:31 95.9 97.3 98.3 98.5 525 627 657 584 627 657 -422 175 146 233 175 146 AR 41 9:01 -99.9 97.3 98.3 98.5 627 744 759 627 744 846 219 204 131 -422 204 131 AR 42 12:16 97.6 96.5 98.0 97.5 5792 5238 6317 5938 5223 6449 1167 1021 1386 1371 1050 1503 AR 42 12:46 97.5 96.5 98.0 97.5 6026 5369 6390 6230 5457 6697 1474 1123 1532 1459 1138 1619 BA 01 10:01 100 98.1 98.6 98.9 1232 1390 1464 1237 1427 1506 277 393 229 251 -7 -244 BA 01 20:01 97.3 98.1 98.6 98.9 1406 1601 1575 1448 1596 1516 303 24 -239 356 462 266 BA 04 10:31 -100 100.0 -99.8 -99.6 1089 989 978 1137 1000 984 261 277 198 287 -118 -181 BA 04 17:16 99.3 100.0 -99.8 -99.6 1791 1633 1427 1865 1627 1432 219 -228 -424 324 208 55 BAR43 5:16 98.9 94.9 95.3 95.1 3341 3268 3020 3472 3356 3151 802 248 -72 802 306 379 BAR43 10:31 96.8 94.9 95.3 95.1 5690 5690 5165 5792 5675 5150 1882 1328 1503 1940 1298 1036

  6. This Reading Bank Shot Report 9-1-04 Righr Half of Spreadsheet Load Compensated Delta Delta Delta Estimated Estimated TOTAL BANKS ON CIRCUIT Delta kvars Delta kvars Delta kvars Estimated BANK Angle Angle Angle Kvars at Actual Kvars CKT A B C ABC SIZE? ABC A B C 90% PF KVAR ONLINE VARS AD 04 172 185 44 ==. 600 6.135 5.984 -0.007 ==. 2086 654 1432 5400 450Q,600Q,600TQ,1200F,1200Q,1350Q AD 04 -374 -418 -24 ++. 1200 -15.015 -18.015 0.004 ++. 2092 -251 2343 5400 450Q,600Q,600TQ,1200F,1200Q,1350Q AD 04 -390 -388 -46 ++. 1200 -10.897 -11.472 0.004 ++. 2907 -511 3418 5400 450Q,600Q,600TQ,1200F,1200Q,1350Q AD 04 207 218 25 ==. 600 4.685 5.42 -0.001 .=. 3503 225 3278 5400 450Q,600Q,600TQ,1200F,1200Q,1350Q AD 04 397 447 35 ==. 1200 9.956 11.926 -0.002 ==. 3230 918 2312 5400 450Q,600Q,600TQ,1200F,1200Q,1350Q AD 09 -395 -465 -40 ++. 1350 -16.959 -18.648 -1.8 ++. 2253 -823 3076 3300 600F,600F,900Q,1200TQ AD 09 397 411 55 ==. 1200 15.134 11.163 0.68 ==. 2862 1379 1483 3300 600F,600F,900Q,1200TQ AF 01 32 443 467 .== 1350 0.861 12.836 12.063 .== 2686 2471 215 4800 900F,1200Q,1350Q,1350T AF 01 -21 -440 -548 .++ 1800 -0.59 -13.845 -15.036 .++ 2612 1338 1274 4800 900F,1200Q,1350Q,1350T AF 02 29 -216 -200 .++ 600 0.921 -8.757 -9.458 .++ 1800 -380 2180 4200 600T,600F,900Q,900TQ,1200TQ AF 06 -163 -198 -32 ++. 600 -1.187 -6.89 0.072 .+. 2116 -2215 4331 2900 200Q,450TQ,450F,600F,600T,600TQ AF 06 200 195 -23 ==. 600 3.144 7.686 -0.047 .=. 2364 -1027 3391 2900 200Q,450TQ,450F,600F,600T,600TQ AF 07 -271 16 -169 +.. 900 -6.548 1.334 -3.597 +.. 2546 694 1852 2700 600F,900Q,1200T AF 07 303 -21 182 =.. 900 8.011 -0.687 4.605 =.. 2456 1068 1388 2700 600F,900Q,1200T AF 10 -437 0 -400 +.+ 1200 -25.927 0.027 -16.352 +.+ 1705 110 1595 3600 900F,1350Q,1350TQ AN 04 -35 302 13 .=. 900 -0.978 8.777 -0.099 .=. 2624 1430 1194 3900 600F,900Q,1200T,1200TQ AN 05 -184 -204 181 ++= 600 -4.335 -3.662 4.527 ... 3002 -429 3431 4500 600F,600TQ,900T,1200Q,1200TQ AN 05 163 173 -188 ==+ 600 6.249 3.904 -7.125 =.+ 2577 -599 3176 4500 600F,600TQ,900T,1200Q,1200TQ AN 06 -19 374 404 .== 1200 -0.473 10.041 9.959 .== 3131 1991 1140 3600 1200T,1200Q,1200F AN 06 -51 -448 -506 .++ 1350 -0.581 -10.187 -10.998 .++ 3322 1181 2141 3600 1200T,1200Q,1200F AN 07 -447 -453 13 ++. 1350 -11.706 -14.186 0.416 ++. 2805 -631 3436 3600 600F,900Q,900T,1200TQ AN 07 485 470 36 ==. 1350 16.918 19.397 2.074 ==. 2068 -613 2681 3600 600F,900Q,900T,1200TQ AN 09 14 318 326 .== 900 -0.388 9.864 11.607 .== 2120 901 1219 3600 600T,900F,900Q,1200TQ AN 09 14 -306 -304 .++ 900 0.957 -10.405 -9.346 .++ 2467 -167 2634 3600 600T,900F,900Q,1200TQ AN 10 0 -509 -23 .+. 1800 -0.049 -22.585 -0.615 .+. 1959 1294 665 3150 600T,1200T,1350Q AN 10 -19 470 -10 .=. 1350 -0.158 21.21 -0.987 .=. 2031 207 1824 3150 600T,1200T,1350Q AR 41 625 0 0 =.. 1800 60.543 0 0 =.. 934 554 380 600 600Q AR 41 -641 0 -43 +.. 1800 -53.196 0 -0.99 +.. 1108 -87 1195 600 600Q AR 42 131 36 51 =.. 450 1.609 0.337 0.744 ... 8805 3924 4881 7050 450TQ,900TQ,900Q,1200F,1800T,1800TQ AR 42 -117 -29 -66 +.. 300 -0.565 -0.034 0.108 ... 9192 4216 4976 7050 450TQ,900TQ,900Q,1200F,1800T,1800TQ BA 01 -28 -418 -494 .++ 1350 -1.201 -16.068 -18.093 .++ 2085 0 2085 2100 900F,1200Q BA 01 32 440 534 .== 1800 1.651 15.286 18.58 .== 2280 1084 1196 2100 900F,1200Q BA 04 2 -400 -382 .++ 1200 0.689 -22.376 -21.868 .++ 1560 -12 1572 1950 600F,1350T BA 04 68 439 476 .== 1350 2.884 15.234 18.748 .== 2462 587 1875 1950 600F,1350T BAR43 -65 14 385 ..= 1200 -0.492 0.87 8.224 ..= 4989 1487 3502 7300 1200T,1200Q,1300T,1800F,1800TQ BAR43 7 -22 -459 ..+ 1350 0.216 -0.254 -4.851 ..+ 8308 4274 4034 7300 1200T,1200Q,1300T,1800F,1800TQ

  7. Bank Shot Report 9-1-04 Critical Information Load Compensated Delta Delta Delta 9/1/2004 BANKS ON CIRCUIT Peak Delta kvars Delta kvars Delta kvars Estimated Angle Angle Angle CKT TIME PF A B C ABC SIZE? ABC A B C ==. ==. AD 04 1:16 100.0 172 185 44 600 6.135 5.984 -0.007 450Q,600Q,600TQ,1200F,1200Q,1350Q ++. ++. AD 04 9:31 100.0 -374 -418 -24 1200 -15.015 -18.015 0.004 450Q,600Q,600TQ,1200F,1200Q,1350Q ++. ++. AD 04 12:16 100.0 -390 -388 -46 1200 -10.897 -11.472 0.004 450Q,600Q,600TQ,1200F,1200Q,1350Q ==. .=. AD 04 21:16 100.0 207 218 25 600 4.685 5.42 -0.001 450Q,600Q,600TQ,1200F,1200Q,1350Q ==. ==. AD 04 21:46 100.0 397 447 35 1200 9.956 11.926 -0.002 450Q,600Q,600TQ,1200F,1200Q,1350Q AD 09 12:01 99.9 -395 -465 -40 ++. 1350 -16.959 -18.648 -1.8 ++. 600F,600F,900Q,1200TQ AD 09 21:46 99.9 397 411 55 ==. 1200 15.134 11.163 0.68 ==. 600F,600F,900Q,1200TQ .== .== AF 01 1:01 99.8 32 443 467 1350 0.861 12.836 12.063 900F,1200Q,1350Q,1350T .++ .++ AF 01 9:46 99.8 -21 -440 -548 1800 -0.59 -13.845 -15.036 900F,1200Q,1350Q,1350T .++ .++ AF 02 8:01 -100.0 29 -216 -200 600 0.921 -8.757 -9.458 600T,600F,900Q,900TQ,1200TQ AF 06 12:01 -97.9 -163 -198 -32 ++. 600 -1.187 -6.89 0.072 .+. 200Q,450TQ,450F,600F,600T,600TQ AF 06 23:01 -97.9 200 195 -23 ==. 600 3.144 7.686 -0.047 .=. 200Q,450TQ,450F,600F,600T,600TQ AF 07 13:01 99.6 -271 16 -169 +.. 900 -6.548 1.334 -3.597 +.. 600F,900Q,1200T AF 07 13:16 99.6 303 -21 182 =.. 900 8.011 -0.687 4.605 =.. 600F,900Q,1200T +.+ +.+ AF 10 10:01 -99.8 -437 0 -400 1200 -25.927 0.027 -16.352 900F,1350Q,1350TQ .=. .=. AN 04 22:46 96.7 -35 302 13 900 -0.978 8.777 -0.099 600F,900Q,1200T,1200TQ ++= ... AN 05 14:46 -99.9 -184 -204 181 600 -4.335 -3.662 4.527 600F,600TQ,900T,1200Q,1200TQ AN 05 22:16 -99.9 163 173 -188 ==+ 600 6.249 3.904 -7.125 =.+ 600F,600TQ,900T,1200Q,1200TQ AN 06 2:31 97.6 -19 374 404 .== 1200 -0.473 10.041 9.959 .== 1200T,1200Q,1200F AN 06 9:31 97.6 -51 -448 -506 .++ 1350 -0.581 -10.187 -10.998 .++ 1200T,1200Q,1200F ++. ++. AN 07 19:01 99.7 -447 -453 13 1350 -11.706 -14.186 0.416 600F,900Q,900T,1200TQ ==. ==. AN 07 22:46 99.7 485 470 36 1350 16.918 19.397 2.074 600F,900Q,900T,1200TQ .== .== AN 09 0:31 99.3 14 318 326 900 -0.388 9.864 11.607 600T,900F,900Q,1200TQ .++ .++ AN 09 9:31 99.3 14 -306 -304 900 0.957 -10.405 -9.346 600T,900F,900Q,1200TQ .+. .+. AN 10 8:01 99.6 0 -509 -23 1800 -0.049 -22.585 -0.615 600T,1200T,1350Q .=. .=. AN 10 22:01 99.6 -19 470 -10 1350 -0.158 21.21 -0.987 600T,1200T,1350Q AR 41 4:31 98.5 625 0 0 =.. 1800 60.543 0 0 =.. 600Q AR 41 9:01 98.5 -641 0 -43 +.. 1800 -53.196 0 -0.99 +.. 600Q AR 42 12:16 97.5 131 36 51 =.. 450 1.609 0.337 0.744 ... 450TQ,900TQ,900Q,1200F,1800T,1800TQ AR 42 12:46 97.5 -117 -29 -66 +.. 300 -0.565 -0.034 0.108 ... 450TQ,900TQ,900Q,1200F,1800T,1800TQ .++ .++ BA 01 10:01 98.9 -28 -418 -494 1350 -1.201 -16.068 -18.093 900F,1200Q .== .== BA 01 20:01 98.9 32 440 534 1800 1.651 15.286 18.58 900F,1200Q .++ .++ BA 04 10:31 -99.6 2 -400 -382 1200 0.689 -22.376 -21.868 600F,1350T .== .== BA 04 17:16 -99.6 68 439 476 1350 2.884 15.234 18.748 600F,1350T BAR43 5:16 95.1 -65 14 385 ..= 1200 -0.492 0.87 8.224 ..= 1200T,1200Q,1300T,1800F,1800TQ BAR43 10:31 95.1 7 -22 -459 ..+ 1350 0.216 -0.254 -4.851 ..+ 1200T,1200Q,1300T,1800F,1800TQ

  8. Report Sent to Field Forces

  9. Low Power Factor Report • Pulls in power factor at peak, 4:46 PM, for every circuit on the system for 5 consecutive days. • Pulls in caps from capacitor database. • Calculates the theoretical power factor with all caps on, as well as the number of KVARS off-line. • The key is to look for circuits with a low power factor over those 5 days (less that 98%) and with a meaningful magnitude of KVARS off-line. • There is no reason to send a crew to a circuit with a poor power factor if all of the caps are working, and there is no reason to send a crew to a circuit with excellent power factor even if some of the caps are off-line.

  10. Report Sent to Field Forces

  11. Results • Piloted this effort during the 2nd half of 2004. • Good success rate. • In almost all cases, the crews were finding problems on the circuits identified. • Crews were entering their work into the Capacitor Database. • Needed to develop tracking mechanism and provide monthly reports on the progress of the crews.

  12. Issues • Needed to integrate this analysis effort into larger capacitor maintenance / capacitor construction program. • Issues: • Capacitor crews & supervision had other priorities. • Work orders & construction of new capacitors was not timely. • Material shortages at certain times of the year (Long lead times on materials, plus inventory reduction). • New products such as vacuum switches & cutouts. • The creator of Capacitor Database left the company.

  13. Capacitor Program • Capacitor construction strategy • Capacitor material strategy • Capacitor maintenance strategy

  14. Capacitor Construction Strategy • Established timeline for new capacitor construction: • 1. Identify & issue material requirements to Purchasing based on development plans by 9/1 • 2. Issue next year’s construction schedule by 9/1 • 3. Engineering to write work orders by 10/30 • 4. Material purchases to be driven by bill of materials on work orders via SAP • 5. CW Utilities to assemble materials in kits for each work order & deliver to S/C via cross-dock with central stores • 6. Complete construction by 3/31 • 7. Track orders via SAP (10/1 - 3/31)

  15. Capacitor Construction Strategy • Benefits: • Caps completed sooner in the year so crews will be available for maintenance as the weather warms up. • (Previous focus was simply to get the banks built by 6/1) • Materials for construction will ordered based on material requirements of work orders. • Better utilization of materials since construction crews will not be taking the materials needed for maintenance or for other construction jobs.

  16. Capacitor Material Strategy Goal: Accurately identify material needs for new construction Accurately identify material needs for maintenance Acquire materials on a more timely basis Utilize better materials where necessary

  17. Capacitor Material Strategy • Revised inventory purchase thresholds based on: • 1. Annual & monthly maintenance requirements (avg & peak values to account for weather impacts) • 2. Lead time for each material • Perform monthly review of materials on hand, on order and at CW Utilities. • Order specific materials if necessary. • Establish metrics on material acquisition and usage to measure how effective we are on material strategy.

  18. Capacitor Material Strategy • Metric: Fill rate = % of time material is available when you need it. • 2004 overall fill rate was 84% • Goal for capacitor materials is 98 - 100% • Fill rate will be calculated for each material item

  19. Capacitor Maintenance Strategy • Established priorities for capacitor crews: • 1. Banks identified by Capacitor Analysis • 2. Banks identified by RCCS • 3. Switching orders for banks taken out of service • 4. Banks with hot spot identified by infra-red • 5. Field reports of banks out of service • 6. Construction for planned capacitor work • 7. Other work • Held meetings with crews & their management to review priorities. • Established flow chart for entire maintenance process.

  20. Conclusion • Implementation currently underway. • Will see how it works in the 2005 - 2006 season.

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