Generator Interconnection Impact Study Report Richmond County, NC 1402 MW Queue #85

Transcription

1 Generator Interconnection Impact Study Report Richmond County, NC 1402 MW Queue #85, Inc.

2 Introduction The following impact study results are from the Progress Energy Inc., Carolinas (PEC) internal power-flow models that reflect specific conditions of the PEC system at points in time consistent with the generator interconnection request being evaluated. The cases include the most recent information for load, generation additions, transmission additions, interchange, and other pertinent data necessary for analysis. Future years may include transmission, generation, and interchange modifications that are not budgeted for and for which no firm commitments have been made. Further, PEC retains the right to make modifications to power-flow cases as needed if additional information is available or if specific scenarios necessitate changes. For the systems surrounding PEC, data is based on the NERC MMWG model. The suitability of the model for use by others is the sole responsibility of the user. The Customer and PEC entered into this agreement on Jan. 5, Higher queued generator interconnection requests #80, #81, #82, and #84 as well as the associated Network Upgrades were included in this analysis. Facilities to address transmission issues associated with higher queued request #84 were needed as a starting point for this study. Therefore, this generator interconnection impact study was commenced following the completion of the generator interconnection facility study for request #84, also located at Richmond County. Study work started on or about April 1, Purpose The purpose of this study is to assess the impact of a generator interconnection request on the reliability of the PEC transmission system with respect to power-flow, stability, and short circuit issues. The PEC internal system analysis consists of an evaluation of the internal PEC transmission system utilizing documented transmission planning criteria. The request is described in Table 1 below. The Customer s application proposed interconnection at 230 kv to PEC s Richmond 500 kv substation. A conference call between PEC and the Customer took place on April 15, In this meeting PEC shared preliminary results of studies to date. In this meeting it was agreed to proceed with studies assuming interconnection at the 500 kv level at the Richmond 500 kv Substation. Subsequent investigation revealed insufficient room in the Richmond 500 kv switchyard to accommodate the new units. A revised Point-of- Interconnection was therefore chosen to be on the Richmond-Newport 500 kv line approximately one-half mile from the Richmond 500 kv Substation. PEC Generator Interconnection Queue No. MW In-Service Date Table 1: Request County Queue # /01/08 Richmond County, North Carolina Facility PEC Richmond 500kV Substation - 2 -

3 Results Power-flow Analysis Facilities that may require upgrade within the first three to five years following the in-service date are identified. Based on projected load growth on the PEC transmission system, facilities of concern are those with post-contingency loadings of 95% or greater of their thermal rating and low voltage of 0.92 pu and below for the requested in-service year. The identification of these facilities is crucial due to the construction lead times necessary for certain system upgrades. This process will ensure that appropriate focus is given to these problem areas to investigate whether construction of upgrade projects is achievable to accommodate the requested interconnection service. Based on 2008 study results, Table 2 shows thermal facility loadings that were found: Table 2: Power-flow Thermal Results Transmission Facility Loading Contingency Delco Whiteville 115 kv line 150% Brunswick Unit #2 Whiteville 230 kv line Weatherspoon Plant Raeford 115 kv line 129% Weatherspoon Plant 230/115 kv transformer Fayetteville 230/115 kv #1 (#2) 126% Fayetteville 230/115 kv #2 (#1) transformer transformer Fayetteville Fayetteville East 230 kv line 120% Fayetteville Ft. Bragg Woodruff St. 230 kv line Richmond 500/230 kv #1 transformer 119% Cumberland Richmond 500 kv line Weatherspoon Plant Marion 115 kv line 119% Weatherspoon Plant 230/115 kv transformer Weatherspoon Plant 230/115 kv 118% Weatherspoon Plant Raeford 115 kv line transformer Cape Fear Erwin 115 kv line 118% Harris Plant Erwin 230 kv line Clinton Vander 115 kv line 115% Clinton Erwin 230 kv line Rockingham Anson 230 kv Black line 115% Richmond New Gen Site 500 kv line Rockingham Anson 230 kv White line 115% Richmond New Gen Site 500 kv line Sutton Plant Castle Hayne 230 kv line 114% BNP1 Castle Hayne and BNP2- Wilmington Corning 230 kv lines (common tower) Richmond 500/230 kv #2 transformer 113% Cumberland Richmond 500 kv line Greenville DVP Everetts 230 kv line 113% Greenville Wilson 230 kv line Blewett Plant Tillery Plant 115 kv line 112% Biscoe Rockingham 230 kv line Lee Sub Milburnie 230 kv line 110% Lee Sub Selma 230 kv line Rockingham West End 230 kv line 110% Cumberland Richmond 500 kv line Asheboro East Biscoe 115 kv line 109% Asheboro Biscoe 230 kv line Raeford Richmond 230 kv line 109% Cumberland Richmond 500 kv line Fayetteville Ft. Bragg Woodruff St % Fayetteville Fayetteville East 230 kv line kv line Cumberland 500/230 kv #1(#2) transformer 107% Cumberland 500/230 kv #2(#1) transformer - 3 -

4 Transmission Facility Loading Contingency Greenville Wilson 230 kv line 105% Greenville DVP Everetts 230 kv line Lee Plant Selma 115 kv line 105% Lee Sub Selma 230 kv line Wake 500/230 kv #1(#2) transformer 105% Wake 500/230 kv #2(#1) transformer Selma Wake 230 kv line 105% Erwin Milburnie and Lee Sub Milburnie 230 kv lines (common tower) Cary Regency Park Durham 230 kv line 105% Method Duke E. Durham and Durham Method 230 kv lines (common tower) Fayetteville Rockingham 230 kv line 104% Cumberland Richmond 500 kv line Blewett Plant Rockingham 115 kv line 104% Biscoe Rockingham 230 kv line Milburnie Selma 115 kv line 103% Selma 230/115 kv transformer Weatherspoon Plant Fayetteville 115 kv 103% Weatherspoon Plant 230/115 kv transformer line Sutton Plant Delco 115 kv line 103% BNP1 Castle Hayne and BNP2- Wilmington Corning 230 kv lines (common tower) Method Duke E. Durham 230 kv line 102% Durham Duke E. Durham 230 kv line Fayetteville Vander South 115 kv line 102% Fayetteville Vander North 115 kv line Laurinburg LOF Black (White) 115 kv 102% Laurinburg LOF White (Black) 115 kv line line Black Creek Wilson West 115 kv line 102% Black Creek Wilson East 115 kv line Cumberland Delco 230 kv line 102% Cumberland Fayetteville N. and S. 230kV lines (common tower) Rockingham West End 230 kv line 100% Cumberland Richmond 500 kv line Falls 230/115 kv transformer 100% Falls Franklinton and Falls Henderson 115 kv lines (common tower) Method Milburnie S. 115 kv line 100% Method Milburnie 230 kv and N. 115 kv line (common tower) Lee Sub Selma 230 kv line 99% Lee Sub Milburnie 230 kv line Laurinburg Richmond 230 kv line 99% Cumberland Richmond 500 kv line Laurinburg 230/115 kv #1 (#2) 99% Laurinburg 230/115 kv #2 (#1) transformer transformer Tillery Plant Biscoe 115 kv line 98% Biscoe Rockingham 230 kv line Weatherspoon Plant Laurinburg 230 kv 98% Cumberland Richmond 500 kv line line Selma 230/115 kv transformer 98% Lee Sub Selma 230 kv line Robinson Plant Florence 115 kv line 97% Cumberland Richmond 500 kv line Durham Falls 230 kv line 96% Roxboro Plant Falls and Roxboro Person 230 kv lines (common tower) Sutton Plant Delco 230 kv line 95% BNP1 Castle Hayne and BNP2- Wilmington Corning 230 kv lines (common tower) Florence Kingstree 230 kv line 95% Richmond Duke Newport 500 kv line - 4 -

5 Based on 2008 study results, Table 3 shows facility low voltages that were found: Number of Low Voltage Buses Lowest Voltage (pu) Table 3: Power-flow Voltage Results Bus Number and Name of Lowest Voltage Contingency Description #10453, PA-WASH 230 Cumberland Delco 230 kv line #10047, WSP 1-3F 115 Cumberland Richmond 500 kv line #10259, E15-Hall 115 Harris Plant Erwin 230 kv line #10451, PA-Grnvl 230 Greenville DVP Everetts 230 kv line #10525, M-LEJN#1 230 Castle Hayne Jacksonville 230 kv line #10525, M-LEJN#1 230 Jacksonville Havelock 230 kv line #10453, PA-Wash 230 BNP1 Jacksonville 230 kv line #10457, Chocwnty 230 BNP2 Whiteville 230 kv line #10451, PA-Grnvl 230 Lee Milburnie 230 kv line #10451, PA-Grnvl 230 Wake Wilson 230 kv line #10451, PA-Grnvl 230 Lee Selma 230 kv line #10259, E15-Hall 115 Clinton Erwin 230 kv line #10229, Farmvill 230 Greenville Wilson 230 kv line #10176, PA-SMFLD 115 Selma Wake 230 kv line #10451, PA-Grnvl 230 Wake DVP Carson 500 kv line #10453, PA-WASH 230 Jacksonville Wallace 230 kv line #10451, PA-Grnvl 230 Mayo Plant Durham 500 kv line #10451, PA-Grnvl 230 BNP1 Weatherspoon 230 kv line #10451, PA-Grnvl 230 Harris Plant Cary Regency Park 230 kv line #10256, CL Ferel 115 Sutton Plant Wallace 230 kv line #10260, Roseboro 115 Harris Plant Ft. Bragg Woodruff St. 230 kv line #10455, I-PCS 230 Aurora Greenville 230 kv line #10451, PA-Grnvl 230 Lee Wommack N. 230 kv line #10451, PA-Grnvl 230 Greenville Greenville West 230 kv line #10441, E10-PEMB 115 Laurinburg Richmond 230 kv line #10451, PA-Grnvl 230 Lee Wommack S. 230 kv line #10451, PA-Grnvl 230 Person Rocky Mt. 230 kv line #10505, ROSE HIL 230 Clinton Wallace 230 kv line #10418, E10-ROCK 115 Raeford Richmond 230 kv line - 5 -

6 Number of Low Voltage Buses Lowest Voltage (pu) Bus Number and Name of Lowest Voltage Contingency Description #10593, WHTV IND 115 Marion Whiteville 115 kv line #10440,E10-WLUM 115 Weatherspoon Plant 230/115 kv transformer #10451, PA-Grnvl 230 Rocky Mt. DVP Nashville 230 kv line #10481,PA-AYDEN 115 Goldsboro Kinston DuPont 115 kv line #10455, I-PCS 230 New Bern Wommack N. 230 kv line #10451, PA-Grnvl 230 Cumberland Whiteville 230 kv line #10265, E15-STED 115 Clinton Vander 115 kv line #10403, HM Churc 115 Weatherspoon Plant Fayetteville 230 kv line #10488, E2-CH PT 115 Havelock Morehead Mildwood N. 115 kv line #10451, PA-Grnvl 230 Richmond Duke Newport 500 kv line #10430, RED SPRG 115 Weatherspoon Plant Raeford 115 kv line #10476, ICG-WYHS 115 Kinston DuPont New Bern 115 kv line #10482, E13-HUGO 115 Kinston DuPont 230/115 kv transformer #10440, E10-WLUM 115 Weatherspoon Plant Laurinburg 230 kv line #10451, PA-Grnvl 230 Jacksonville New Bern 230 kv line #10256, CL Ferel 115 Clinton 230/115 kv transformer #10176, PA-SMFLD 115 Milburnie Selma 230 kv line #10544, HOLLY RG 115 Castle Hayne Jacksonville 115 kv line #10107, E18-WEMC69.0 Falls Franklinton 115 kv line #10242, PA-W Rocky Mt. Wilson E. 115 kv line #10460, E3-MANCH 115 Rockingham West End 230 kv line #10418, E10-ROCK 115 Cumberland Wake 500 kv line #10451, PA-Grnvl 230 Durham Wake 500 kv line #10404, E3-MANCH 115 Weatherspoon Plant Fayetteville 115 kv line #10176, PA-SMFLD 115 Selma 230/115 kv transformer #10495, N RIVER 115 Havelock Morehead Mildwood S. 115 kv line #10658, I-GE FL 115 Florence Marion 115 kv line #10084, I-NOVO 115 Franklinton Spring Hope 115 kv line #10572, ELIZABTN 115 Weatherspoon Plant Delco 115 kv line #10440, E10-WLUM 115 Weatherspoon Plant Laurinburg 115 kv line #10451, PA-Grnvl 230 Rocky Mt. Wilson 230 kv line #10484, Havelock 230 Havelock Jacksonville 230 kv line #10460, E3-MANCH 115 Fayetteville Ft. Bragg Woodruff St. 230 kv line - 6 -

7 Number of Low Voltage Buses Lowest Voltage (pu) Bus Number and Name of Lowest Voltage Contingency Description #10262, E17-MT O 115 Mt. Olive 230/115 kv transformer #10451, PA-Grnvl 230 New Bern Wommack S. 230 kv line #10451, PA-Grnvl 230 Havelock Morehead Mildwood 230 kv line #10453, PA-WASH 230 Cumberland Whiteville 230 kv line #10449, DILLON 115 Weatherspoon Plant Marion 115 kv line #10145, NEUSE 115 Chestnut Hills Falls 115 kv line #10418, E10-ROCK 115 Laurinburg Raeford 230 kv line #10418, E10-ROCK 115 Raeford 230/115 kv #1 transformer #10266,E17-Geno 115 Lee Plant Clinton 230 kv line #10281, Belfast 115 Lee Plant Goldsboro N. 115 kv line #10418, E10-ROCK 115 Fayetteville Rockingham 230 kv line #10451, PA-Grnvl 230 Harris Plant Wake 230 kv line #10451, PA-Grnvl 230 Erwin Selma 230 kv line #10451, PA-Grnvl 230 BNP2 Wallace 230 kv line #10451, PA-Grnvl 230 Milburnie Person 230 kv line #10451, PA-Grnvl 230 Delco Whiteville 115 kv line #10451, PA-Grnvl 230 Sutton Plant Castle Hayne 230 kv line #10451, PA-Grnvl 230 Roxboro Plant Falls 230 kv line #10451, PA-Grnvl 230 Durham Duke E. Durham 230 kv line #10451, PA-Grnvl 230 Kinston DuPont Wommack 230 kv line Based on 2008 study results, Table 4 shows overloads of 230 kv bus equipment at the Richmond 500 kv Substation: Table 4: Power-flow Bus Thermal Results Richmond 230 kv Bus Section Loading Contingency Rockingham#1-Raeford 230 kv Bay 131% Rockingham #1 230 kv Bus CB Richmond Co. White-#1 500/230 kv Bank Bay 122% Richmond Co.230 kv Bus CB OR #1 500/230 kv Bank Bus CB Stability Analysis A detailed stability analysis to determine the impacts that Queue #85 generation has on system stability would normally be performed as part of this Generator Interconnection Impact Study. Significant influences to the results of a stability analysis are the location of the proposed generating units, interconnect ion to the transmission system, and the configuration of the - 7 -

8 surrounding transmission. As evidenced by the Power-flow Analysis section of this report, a large number of facility thermal loading and low voltage issues were identified due to the addition of the Customer s generation. Performing a detailed stability analysis prior to resolution of these power-flow issues would be of little or no value due to the uncertainty of the system configuration necessary to remedy the power-flow issues. Nevertheless, based on prior analysis, stability issues are probable. Stability issues will likely be aggravated without inclusion of the upgrades needed to address the identified thermal and voltage issues. Based on the above, a detailed stability analysis will be included in Generator Interconnection Facilities Study. Based on PEC s current generator interconnection queue status, the stability analysis would include higher queued generator interconnection requests #80, #81, #82 and #84. Any changes to the queue with respect to these other requests will be incorporated as necessary. Additionally, it can be noted that prolonged oscillations following system disturbances in the PEC transmission system can occur under certain system conditions due to the minimal natural damping available. It is likely that the installation of power system stabilizers on the proposed generating units will be needed to mitigate the adverse impact that adding the proposed generation will have in contributing to these prolonged oscillations. Short Circuit Analysis A short circuit analysis was performed to examine the fault current levels at the 115 kv, 230 kv and 500 kv levels one and two substations away from the proposed Richmond County Queue #85 generation. The proposed generation was assumed to be interconnected to the Richmond-Newport 500 kv line near PEC s Richmond 500 kv Substation via an individual generator step-up transformer for each of the six generating units. The transmission system configuration modeled also included proposed generation additions, with related system changes, for higher queued requests 80, 81, 82 and 84. Results of this analysis indicate that the interrupting capability of three 230 kv, 54 ka circuit breakers at Richmond 500/230 kv Substation will be exceeded with the addition of Queue #85 Richmond County generation. Additionally, eleven 230 kv, 50 ka circuit breakers at the existing PEC Richmond County Plant would be near their interrupting capability limit and may also need to be replaced. The results of this short circuit analysis are based on Customer provided generation equipment data, location, and the use of typical data for the generator step-up transformers. If the generation equipment data or location changes, the results of this analysis may need to be reevaluated. Additionally, it is anticipated that these short circuit results will need to be reevaluated to address system configuration changes needed to resolve the large number of power-flow issues identified in the Power-flow Analysis section of this report