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JWG-B2/B4/C1.17 Impacts of HVDC Lines on the Economics of HVDC Projects Task Force JWG-B2/B4/C1.17 Brochure 388 Jose Antonio Jardini João Felix Nolasco John Francis Grahan Günter Bruske jardini@pea.usp.br nolascojf@gmail.com john.graham@br.abb.com bruske@siemens.com

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JWG-B2/B4/C1.17 Impacts of HVDC Lines on the Economics of HVDC Projects From José Antonio Jardini, João Felix Nolasco on behalf of CIGRE JWG-B2.17/B4/C1.17 João Francisco Nolasco, JWG Convenor (Brazil); José Antonio Jardini, TF Convenor (Brazil); John Francis Graham, Secretary (Brazil) Regular members: João F. Nolasco (Brazil); John F. Graham (Brazil); José A. Jardini (Brazil); Carlos A.O. Peixoto (Brazil); Carlos Gama (Brazil; Luis C. Bertola (Argentina); Mario Masuda (Brazil); Rogério P. Guimarães (Brazil); José I. Gomes (Brazil); P. Sarma Maruvada (Canada); Diarmid Loudon (Norway); Günter Bruske – (Germany); Hans-Peter Oswald (Germany); Alf Persson (Sweden); Walter Flassbeck (Germany) Corresponding members: Kees Koreman (Netherlands); Tim Wu (USA); Dzevad Muftig (South Africa); Bernard Dalle (France); Pat Naidoo (Zaire); José Henrique M. Fernandes (Brazil); Jutta Hanson (Germany); Riaz Amod Vajeth (Germany); Angus Ketley (Australia) Reviewers: Rob Stephen (South Africa); Elias Ghannoun (Canada); Samuel NguefeuGabriel Olguin (Chile) (France)

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JWG-B2/B4/C1.17 Content Overview and Configurations Studied Transmission Line Considerations Converter Station Cost Equation Electrodes, Electrode Lines and Metallic Return System Economics Conclusions REFERENCES

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JWG-B2/B4/C1.17 Overview and Configurations Studied Configurations Table 3.1 Transmission line configuration capacities

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JWG-B2/B4/C1.17 Figure 3.2.a Ground Return Figure 3.2.b Metallic Return System Configuration

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JWG-B2/B4/C1.17 Table 3.2 Cases studied Bipole750 MW1,500 MW3,000 MW6,000 MW 750 km ± 300 kV ± 500 kV± 600 kV ± 500 kV 1,500 km± 300 kV± 500kV ± 600 kV ± 500 kV ± 600 kV± 800 kV 3,000 km ± 500 kV± 600 kV ± 800 kV

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JWG-B2/B4/C1.17 Table 3.3 Converter configurations studied 123456789101112 Bipolar (MW) 750 1,500 3,000 6,000 Rating (kV) ±300 ±500±300±500 ±600±800±600±800 Conv/ poleVSC 1x6 pulse1111111 2 parallel2 series 2 parallel

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JWG-B2/B4/C1.17 One per pole - 3,000 MW Two Series - 6,000 MW Two Parallel - 6,000 MW Figure 3.3 Basic converter station configurations

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JWG-B2/B4/C1.17 Transmission Line Considerations

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JWG-B2/B4/C1.17 TOPICS Overvoltages Insulation Coordination Corona Effects and Fields Line cost Line economics

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JWG-B2/B4/C1.17 Overvoltages Switching Surge Operating Voltage Lightning

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JWG-B2/B4/C1.17

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Switching Surge Related to (L-C) oscillations Energization Reclosing Fault Clearing Load Rejection Resonances All above are important in the AC side of the stations (limitted by surge arrester) DC side control ramp up and ramp down (no overvoltages) Fault Application (the only one to be considered)

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JWG-B2/B4/C1.17 Modeling

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JWG-B2/B4/C1.17 Fault at mid point of the line base case overvoltage profile

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JWG-B2/B4/C1.17 red middle, green end; of the sound pole (1,500 km line) Figure 4.2: Fault at mid point of the line, base case, overvoltage profile.

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JWG-B2/B4/C1.17 Figure 4.8: 3,000 km Transmission Line

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JWG-B2/B4/C1.17 Table 4.2: Sensitivity of the results. Maximum overvoltage at mid point of one pole, fault at mid point of the other pole.

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JWG-B2/B4/C1.17 Insulation Coordination Operating Voltage Switching Surge Lightning Surge Insulator String Clearances to (tower, Guy wires, Cross arm, ground, objects at ground)

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JWG-B2/B4/C1.17 Contamination Severity HVDC very light light moderate heavy leakage distance cm/kV 2 - 2.5 2.5 – 3.2 3.2 – 4 4 - 7 HVAC IEC71-1 light medium heavy very heavy cm/kV(ph-ph rms) 1.6 2.0 2.5 3.1

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JWG-B2/B4/C1.17 - Anti-fog insulator, pitch of 165mm and leakage distance 508mm; -hardware length: 0,25m. ITAIPU 27 mm/kV OK Operating Voltage (kV) Creepage distance 30mm/kV Insulators Number String Length (m) (*) 300183,22 500305,20 600366,20 800488,17

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JWG-B2/B4/C1.17

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Operating Voltage Clearances Table 4.4: Clearances for operating voltages (m).

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JWG-B2/B4/C1.17 REGION I Line altitude: 300 to1000 m Average temperature: 16ºC Ratio of vertical/horizontal span : 0.7 wind return period: 50 years Alfa of Gumbel distribution (m/s) -1 : 0.30 Beta of Gumbel distribution (m/s): 16.62 Distribution with 30 years of samples Note: mean wind intensity 10 min 18.39 m/s standard deviation of 3.68 m/s. wind intensity is 29.52 m/s for 50 year return period Terrain classification: B calculations based on CIGRE Brochure 48 REGION II ICE

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JWG-B2/B4/C1.17 Swing Angle to be used together with Operating Voltage Clearances Conductor codeMCM Aluminum mm 2 Swing Angle ( ) Joree 2,5151274.35 44.5 Thrasher 2,3121171.49 45.6 Kiwi 2,1671098.02 46.9 2,034 1030.63 47.7 Chukar 1,780901.93 47.5 Lapwing 1,590805.65 49.5 Bobolink 1,431725.09 50.7 Dipper 1,351.5684.80 51.4 Bittern 1,272644.52 52.0 Bluejay 1,113563.93 53.4 Rail 954483.39 55.0 Tern 795402.83 56.7 1MCM=0.5067 mm 2

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JWG-B2/B4/C1.17 Insulation Coordination for Switching Surge V50= k 500 d 0,6 V50 is the insulation critical flashover (50% probability) in kV d is the gap distance in m k is the gap factor: K= 1,15 conductor-plane K= 1,30 conductor–structure under K= 1,35 conductor–structure (lateral or above) K= 1,4 conductor-guy wires K= 1,50 conductor–cross arms (with insulator string)

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JWG-B2/B4/C1.17

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Risk of Failure P1 Withstand (1- P1) N gaps withstand (1- P1) n Risk n 1-(1- P1) n ~ n P1 P1=0,02 2% with 200 gaps P=4%

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JWG-B2/B4/C1.17

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Figure 4.9: Conductor to tower clearances.

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JWG-B2/B4/C1.17

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CIGRE Brochure 48 Table 4.7: Swing angle to be used together with Switching Surge Clearances according [8] ACSR Conductor code MCM Swing Angle ( ) Joree 2,515 13.4 Thrasher 2,312 13.8 Kiwi 2,167 14.3 2,034 14.6 Chukar 1,780 14.5 Lapwing 1,590 15.3 Bobolink 1,431 15.8 Dipper 1,351.5 16.1 Bittern 1,272 16.4 Bluejay 1,113 17.0 Rail 954 17.7 Tern 795 18.6

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JWG-B2/B4/C1.17 GapSize (m) 750 km 1500 km 2250 km 3000 km Conductor-to-tower 6,087,70 7,95 Conductor-to-cross arm 5,086,336,316,50 Conductor-to-guy wires 5,707,187,177,39 Conductor-to-ground 8,2210,8510,8411,26 Conductor-to-ground (object; 4,5m; under) 6,508,308,298,58 800 kV (I string)

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JWG-B2/B4/C1.17 dmin w 2R

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JWG-B2/B4/C1.17 Pole Spacing Determination Pole Spacing Required for Operating Voltage DP TO = (R + dmin + (L + R) sin ) 2 + w dmin : operating voltage clearance (m) R: bundle’s radius (m) L: insulators string length (m) : swing angle (degree) w: tower width (m)

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JWG-B2/B4/C1.17 I string governed by operating voltage (OV) plus conductor swing

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JWG-B2/B4/C1.17 Table 4.10 - Pole Spacing (m) for Operating Voltage I strings ACSR Conductor Cross Section (MCM) Pole Spacing (m) ± 300 kV ±500 kV±600 kV±800 kV Joree2,5158.212.514.618.8 Thrasher2,3128.312.614.819.1 Kiwi2,1678.412.815.019.3 2,034 8.512.915.119.5 Chukar1,7808.512.915.119.5 Lapwing1,5908.613.115.419.8 Bobolink1,4318.713.315.620.1 Dipper1,351.58.813.415.720.2 Bittern1,2728.813.415.820.3 Bluejay1,1138.913.616.020.6 Rail9549.013.816.220.8 Tern7959.214.016.421.1

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JWG-B2/B4/C1.17 Current capability wind speed (lowest)1 m/s wind angle45 degree ambient temperature35ºC height above sea level300 to 1000 m solar emissivity of surface0.5 solar absorvity of surface0.5 global solar radiation1000 W/m2 R I 2 + W rad = k Δθ + W dessip θ cond = θ ambient + Δθ

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JWG-B2/B4/C1.17

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EDS Every Day Stress condition. Traction 20% of the rupture load. Temperature 20 o C

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JWG-B2/B4/C1.17 Conductor and shield wire height at tallest tower (2 shield wires - for one add 2.5 m to h g) Voltage ( kV)h p (m)h g (m) 30038.344.3 50042.850.8 60044.853.8 80050.861.8 Conductor (hp) and shield wire (hg) heights

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JWG-B2/B4/C1.17 Shield Wire Position position of the shield wire => to provide effective shielding against direct strokes in the conductors. The better coupling => means as closed as possible of the conductor terrain “rolling” hp*= hp b*= (hg-hp) + (Sc-Sg)(2/3) hg*= hp* +b*

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JWG-B2/B4/C1.17 θ ground ground protection shield wire and conductor protection

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JWG-B2/B4/C1.17 Protection angle As the shield wires should be close to the conductors a protection angle of 10 degrees can be assumed when using 2 shield wires. If one shield wire is used than the protection is almost good for tower with V strings. If I string are used than one shield wire may be used in location with low lightning activity.

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JWG-B2/B4/C1.17 Table 4.14: Swing angles for ROW width definition Conductor Swing Angle (degree) ACSR CodeSection (MCM) Joree 2,515 34.1 Thrasher 2,312 35.1 Kiwi 2,167 36.4 2,034 37.2 Chukar 1,780 37.0 Lapwing 1,590 39.1 Bobolink 1,431 40.4 Dipper 1,351.5 41.1 Bittern 1,272 41.9 Bluejay 1,113 43.5 Rail 954 45.4 Tern 795 47.5

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JWG-B2/B4/C1.17 Right Of Way ( I strings) Operating Voltage plus conductor swing due to high wind. Verification of corona effects and fields

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JWG-B2/B4/C1.17 Corona effects and Fields

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JWG-B2/B4/C1.17 Corona Visual G < 0.95 G 0

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JWG-B2/B4/C1.17

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RI → radio interference level measured at a distance D from the positive pole with a CISPR instrument, dB above 1 μV/m g i → maximum bundle gradient, kV/cm d → conductor diameter, cm f → frequency, MHz D → radial distance from positive pole, m q → altitude, m Radio Interference CIGRE

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JWG-B2/B4/C1.17

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Criteria: at the edge of the right of way SNR = 20 dBu Signal 66 dBu => Noise = 46 dBu Noise=46 dBu. 50% value? in which season? needs statistical consideration subtract 4 dBu Noise 42 dBu for 90% probability

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JWG-B2/B4/C1.17 Figure 4.24: Right of way width, ±500 kV lines (for RI)

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JWG-B2/B4/C1.17 + g → average maximum bundle gradient, kV/cm n → number of sub-conductors d → conductor diameter, cm R → radial distance from the positive conductor to the point of observation The empirical constants k and AN 0 are given as: k = 25.6 for n 2 k = 0 for n = 1,2 AN 0 = -100.62 for n 2 AN 0 = -93.4 for n = 1,2 Audible Noise CIGRE

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JWG-B2/B4/C1.17

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day night probability Acceptable Ldn = 55 dBA subtract 5 dBA for 10% probability ( not exceeding) Ld=Ln= 42 dBA 50% values

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JWG-B2/B4/C1.17 Figure 4.25: Right-of-way width, ±500 kV line (for AN)

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JWG-B2/B4/C1.17 Figure 4.25: Right-of-way width (RI and AN), ± 500 kV, 3 cond. /pole

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JWG-B2/B4/C1.17 Table 4.21: ROW (m) requirements for ±600 kV lines, I strings. kVnMCM ROW RI ROW AN 600 3 2,5157052 2,1677662 1,7808078 600 4 2,5154816 1,7805230 1,1136260 600 5 2,5153016 1,7803416 7955044 Table 4.22: ROW (m) requirements for ±800 kV lines, I strings. kVnMCM ROW RI ROW AN 800 4 2,51576144 * 2,16776144 * 1,59088- 800 5 2,5155080 2,1675496 1,27264136** 800 6 2,5152034 1,5904074 1,2724694 Notes: * If the criteria are relaxed by 2 dB, then the right of way can be reduced to 90 and 100 m, ** If the criteria are relaxed by 2 dB, then the right of way can be reduced to 100 m.

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JWG-B2/B4/C1.17 Figure 4.27: Half ROW and gradient for 500 kV bipole having three conductors per pole.

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JWG-B2/B4/C1.17 a)- maximum saturated values, within right of way (in the ground, close to conductors, bipolar lines) [15]. P= pole spacing (m) H= conductor height (m) V= Voltage (kV) E= Electric field (kV/m) J = Ion flow (A/m 2 ) Electrical Field - Space Charge

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JWG-B2/B4/C1.17 b)maximum saturated values in the ground, at any distance “x” from the tower center provided that

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JWG-B2/B4/C1.17 c) Electrical Field without space charge d)Saturation factor where: k empirical coefficient G= surface gradient (kV/cm) Go empirical coefficient e) Values considering the degree of saturation

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JWG-B2/B4/C1.17 Summer fair (moderated case) - Positive (field and current) peak 50% value Go= 9 kV/cm k= 0.037 95% value Go= 3 kV/cm k= 0.067 - Negative (field and current) peak 50% value Go= 9 kV/cm k= 0.015 95% value Go= 3 kV/cm k= 0.032 Summer height humidity/fog (worst case) - Positive (field and current) peak 50% value Go= 7.5 kV/cm k= 0.06 95% value Go= 3 kV/cm k= 0.086 - Negative (field and current) peak 50% value Go= 8.5 kV/cm k= 0.045 95% value Go= 3 kV/cm k= 0.063

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JWG-B2/B4/C1.17 Table 4.28: Minimum clearance to ground Voltage kV Conductor per pole I strings MCM/MC M I strings Height (m) V string MCM V string Height (m) ±300 11,590/2515> 62,034/2,5156.5 2605/2,5157795/2,5156.5 3336.4/2,5157 6.5 ±500 22,312/2,51510.7None 31,113/2,51511.5 1,351.5/2,51 5 11 4605/2,51511.8795/2,51511 5477/2,51511.8< 477/2,51511 ±600 31,780/2,51513.22,167/2,51513.5 4954/2,51513.81,272/2,51513.5 5605/2,51514.3795/2,51513.5 ±800 42,167/2,51517.52,51517.5 51,272/2,51518.01,590/2,51517.5 6954/2,51518.71,113/2,51517.5 Criteria 12.5 kV/m without space charge

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JWG-B2/B4/C1.17 Table 4.29: Electrical Field Lateral Profile (kV/m), 50% value - Pacific Intertie weather condition E+ (50%)E- (50%) worst (1) 7.9m (1) 22.9mWorst7.9m22.9m summer fair25.427.911.517.218.47.3 Summer high hum., fog32.036.115.027.631.012.8 spring21.624.29.816.117.97.1 w/o space charge9.63.49.63.4 Pacific Intertie meas.10.05.016.010.0 Table 4.30: Electrical Field Lateral Profile (kV/m), 95% value. Pacific Intertie weather conditionE+ (95%)E- (95%) worst (1) 7.9m (1) 22.9mworst7.9m22.9m summer fair36.440.817.127.330.212.4 summer high hum, fog38.943.818.435.439.916.7 spring33.938.216.030.334.114.2 w/o space charge9.63.49.63.4 Pacific Intertie meas.20.015.033.022.0

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JWG-B2/B4/C1.17 Table 4.31: Ion Current Lateral Profile (nA/m²), 50% value weather conditionJ+ (50%) J- (50%) worst (*) 7.9m (*) 22.9mworst7.9m22.9m summer fair52.547.55.532.836.44.2 summer high hum., fog75.768.68.080.088.710.3 spring41.837.84.431.034.44.0 Pacific Intertie meas.2.0 20.05.0 Table 4.32: Ion Current Lateral Profile (nA/m²), 95% value weather conditionJ+ (95%)J- (95%) worst (*) 7.9m (*) 22.9mworst7.9m22.9m summer fair89.280.79.476.785.19.9 summer high hum., fog98.088.710.3113.1125.414.6 spring81.874.08.691.3101.311.8 Pacific Intertie meas.45.020.0125.050.0 Calculation with BPA software resulted in 145.0 and 25.5 nA/m2 at 7.9 and 22.9 m (sic)

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JWG-B2/B4/C1.17 a) Electrical field The electrical field should be bellow 40 kV/m, (correspondent to the level of annoyance “disturbing nuisance”) In fact depend on kV plus nA/m2 b ) Ion current The ion current, value with 95% probability of not being exceeded, in any place, shall not result in a current higher than 3,5 mA “threshold of perception for woman, DC current”. A person has an equivalent area o f 5 m 2, so: GREEN BOOK OLD

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JWG-B2/B4/C1.17 Considerations made Person normally grounded with a current It = 4 mA current through him Person highly insulated touching ground objects, It = 4 mA Person grounded touching large vehicle (grounded through 1 MW).

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JWG-B2/B4/C1.17 Condition I: Through a person with a resistance to ground Rp= 200 Mohm, pass I= 4 uA (they found no measurements with current above 3 uA). The voltage across him will be 800 V and the nuisance is classified as “ No Sensation”. The ion flow in this case is 4/5= 0.8 uA/m2 Condition II: A person with Rp= 500 Mohm and capacitance Cp= 100 pF, subjected to a current of I= 4 uA, touch a grounded object (R=100 ohm). The initial discharge current is than 20A but only 1mA after 0.1 us; the energy is 0.2 mJ (acceptable is 250 mJ “uncomfortable chock”). The ion flow is also 0.8 uA/m2 Condition III: A person Rp= 1500 ohm, Cp=0, touch a truck Ro= 1 Mohm, Co= 10 000 pF where 1000 uA is passing through it ( measurements by Moris in a car 14X2.4X4m placed under a 600 kV line, with a clearance of 2.5 from conductor to truck top was bellow 300 uA). In this case the voltage truck to ground would be 1kV ten initial current is 670 uA, 1mA after 100 us, and an energy of 5 mJ (1/50 of 250 mJ “uncomfortable chock”). The ion flow in this case is 1000/(14*2.4*4)=7.5 uA/m2 Analyzing these conditions it can be proposed the ion flows limits: 0.8 uA/m2 places with access to people 7.5 uA/m2 places with access to truck Note: The criteria above is conservative by at least a factor 10

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JWG-B2/B4/C1.17 Perception of the field

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JWG-B2/B4/C1.17 Reference [46] Chinese 200630 kV/m in the ROW25 kV/m close to building [48] Italian manuscript standard 42 kV/m 1-8 Hz14 kV/m general public (GP) [49] Kosheev RussiaGP=40 kV/m 100 nA/m 2 Work =3600/(E+0.25 E) 2 Health Council Netherland340 kV/m (nothing on blood, reproduction, prenatal mortality DIN40 kV/m60 kV/m for 2 hours B4-4525 kV/m 100 nA/m 2 Probability? season? [51} EPRI proj. 1 proj. 2 (basic) proj. 3 (severe) (kv/m; nA/ m 2 ) no requirements 40; 100 inside ROW 20;20 inside ROW no requirements 10; 5 edge ROW 5;1 edge Criteria Conclusion: 40 kV/m 100 nA/m2 in the ROW 10 kV/m 5 nA/m2 at the edge Worst weather; 5% of not being exceeded Allowance for 1 h work at midspan as per Russian criteria

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JWG-B2/B4/C1.17 Mechanical design

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JWG-B2/B4/C1.17 VoltagePole spacin g PS distance between shield wires H conduct H shield wires Dinsn cond MCMcodeCond sag Shield wire sag (kV)(m) 3008,46,836,942,63,2222167Kiwi22,718,2 3008,56,935,941,63,2241780Chukar21,717,4 50013,411,139,547,25,221272Bittern20,816,6 5001310,739,747,45,231590Lapwing2116,8 50012,810,541,949,65,242167kiwi22,718,2 60015,813,141,550,26,231272Bittern20,816,6 60015,112,442,951,66,241780Chukar21,717,4 6001512,343,952,66,262167Kiwi22,718,2 80020,817,446,256,98,175954Rail20,516,4 80019,315,948,459,18,1752167Kiwi22,718,2

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JWG-B2/B4/C1.17 General dimensions (guyed tower with I string) Voltag e Pole spacin g PS distance between shield wires Conductor Height H shield wires heights H Dins n conduct MCMcode (kV)(m) 3008.46.836.942.63.2222167Kiwi 3008.56.935.941.63.2241780Chukar 50013.411.139.547.25.221272Bittern 5001310.739.747.45.231590Lapwing 50012.810.541.949.65.242167kiwi 60015.813.141.550.26.231272Bittern 60015.112.442.951.66.241780Chukar 6001512.343.952.66.262167Kiwi 80020.817.446.256.98.175954Rail 80019.315.948.459.18.1752167Kiwi

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JWG-B2/B4/C1.17 Minimum Clearances and Swing Angle Volta ge n cond. MCMcode Operating Switching surge (kV) Voltage Clearance (m) Voltage Angle (degree) Clearance to tower (m) Clearance to guy wires (m) Angle (degree) 30022167Kiwi0.746.91.31.237 30041780Chukar0.747.51.31.237.1 50021272Bittern1.2523.062.878.1 50031590Lapwing1.249.53.062.877,5 50042167kiwi1.,246.93.062.877 60031272Bittern1.5524.143.898.1 60041780Chukar1.547.54.143.897.1 60062167Kiwi1.546.94.143.897 8005954Rail1.9556.816.378.8 80052167Kiwi1.946.96.816.377

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JWG-B2/B4/C1.17 Region I without ice Region II with ice. Table 4.39: Region I Design Temperatures (°C) ConditionTemperatures ( º C) EDS Every Day Stress20 Minimum0 Coincident with wind15 Mean maximum30 Table 4.40: Wind data DescriptionData Values Reference height (m)10 Intensity - mean of the sample (m/s) (10 min average wind)18.4 Standard deviation (m/s)3.68 (20% of mean) Sample period (years)30 Ground roughnessB [40} IEC/TR 60826

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JWG-B2/B4/C1.17 Table 4.44: Region II Design Temperatures (°C). ConditionTemperatures ( º C) EDS Every Day Stress (Installation condition) 0 Minimum-18 Ice load condition-5 Table 4.45: Wind data. DescriptionData Values Reference height (m)10 Intensity - mean of the sample (m/s) (10 min average wind)20 Standard deviation (m/s)3.60 (18% of mean) Sample period (years)30 Ground roughnessC Table 4.46: Ice data DescriptionData Values Intensity - mean of the sample - g m (N/m) 16.0 Standard deviation (% of mean)70 Sample period (years)12

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JWG-B2/B4/C1.17 Table 4.47: Ice data- return period Reliability level Return period T (years) Probability of exceeding the load Low probability level of maximum value of one variable 123123 50 150 500 65% 30% 10% High probability level of maximum value of one variable 123123 3100% Table 4.48: Ice/wind combination Loading conditionsIce weightWind velocityEffective drag coefficientDensity Condition 1gLgL V iH C iH δ1δ1 Condition 2gHgH V iL C iH δ1δ1 Condition 3*gHgH V iH C iL δ2δ2

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JWG-B2/B4/C1.17 4- Sag and tension calculations initial state: - EDS Every Day Stress:20% of rupture load for conductor, and 11% for shield wire extra high strength steel. - Temperature 20º C - Creep corresponding to 10 years - High wind simultaneous with temperature of 15 ºC. In this case the tension shall be lower than 50% of the cable rupture load. -At minimum temperature (equal to 0 ºC), with no wind, the tension shall be lower than 33 % of the cable rupture load

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JWG-B2/B4/C1.17 4.3- Tensions An average span of 450 m is considered, and the conditions checked are: - high wind transverse - high wind 45 o - temperature 10ºC, no wind - temperature 0 ºC, no wind - temperature 65 ºC, no wind - storm wind, transverse - storm wind, 45 o - EDS, 20ºC, no wind

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JWG-B2/B4/C1.17 Conductor tensions TOWE R CONDUCTOR TENSION (kgf) Voltag e (kV) Conduct or Code High wind. Transv. High wind 45º Wind 10ºC no Wind 0ºC no Wind 65ºC no Wind Thunde rstorm Wind transv. Thunder storm Wind 45º EDS 20ºC no Wind 300Kiwi6.7755.8904.6185.0364.1665.1664.7634.526 Chukar8.6426.0444.7385.2554.1905.3104.8904.624 500Bittern6.7544.4533.1733.5332.8043.6143.2713.096 Lapwing7.6935.2183.9204.3543.4734.4774.0693.827 Kiwi8.6105.9424.6185.0364.1665.1664.7634.526 600Bittern6.7754.4633.1733.5332.1273.7243.3223.096 Chukar8.8506.1294.7385.2554.1905.3104.8904.624 Kiwi8.6875.9734.6185.0364.1665.1664.7634.526 800Kiwi8.8516.0384.6185.0364.1665.1664.7634.526 Rail5.8283.7062.4132.6942.1272.9532.5632.353

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JWG-B2/B4/C1.17 Tower series The tower and foundation weights are calculated only for suspension tower. Possible line angles are d=0 o, or d=2 o Loading tree

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JWG-B2/B4/C1.17 CodeDescription V0V0 HW at 90º; d = 0; highest VS V OR HW at 90º; d = 0; lowest VS V1V1 HW 90º; d = 2; highest VS V 1R HW at 90º; d = 2; lowest VS V4V4 HW at 450; d = 2; highest VS V 4R HW at 450; d = 2; lowest VS W1W1 TW at 90º; d = 2; highest VS W 1R TW at 90º; d = 2; lowest VS W3W3 TW at 45º; d = 2; highest VS W 3R TW at 45º; d = 2; lowest VS W4W4 TW at 0º; d = 2; highest VS W 4R TW at 0º; d = 2; lowest VS R1R1 No wind; shield wire 1 rupture; d = 2; highest VS R 1R No wind; shield wire 1 rupture; d = 2; lowest VS R2R2 Same as R 1 but for shield wire 2 rupture R 2R Same as R 1R but for shield wire 2 rupture R4R4 No wind; pole 1 conductor 1 rupture; d = 2; highest VS R 4R No wind; pole 1 conductor 1 rupture; d = 2; lowest VS

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JWG-B2/B4/C1.17 R5R5 Same as R 4 but for pole 2 conductor rupture R 5R Same as R 4R but for pole 2 conductor rupture D1D1 No wind longitudinal unbalance; d = 2; highest VS D 1R No wind longitudinal unbalance; d = 2; lowest VS M1M1 Shield wire 1 on shivers and maintenance; d = 2 M2M2 As before; shield wire 2 M4M4 As before; pole 1 conductors M5M5 As before; pole 2 conductors MVRCables on shivers; wind = 0,6 HW MS 1 Shield wire 1 erection; no dynamic forces; d = 2 MS 2 As before; shield wire 2 MS 4 Same as before; pole 1 conductors MS 5 Same as before; pole 2 conductor MS 7 As MS 5 but pole 1 is the last pole to be erected MC 1 Shield wire 1 erection; with dynamic forces; d = 2 MC 2 Same before; shield wire 2 MC 4 Same before; pole 1 conductors MC 5 Same before; pole 2 conductors MC 7 Same as MC 5 but pole 1 is the last to be erected

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JWG-B2/B4/C1.17 Tower weight = a + b V + S (c N + d)ton a, b, c, d are parameters to be obtained by curve fitting of the tower weight data V is the pole to ground voltage (kV) S = N S1 is the total conductor aluminum cross section (MCM); S1 being one conductor aluminum cross section N is the number of conductor per pole a =2,232; b = 7.48; c = 0.091; d = -0.08

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JWG-B2/B4/C1.17 Table 4.53: Regression analysis, tower weight calculation kVN Total section (MCM) Original weight (Ton) Weight from equation (ton) Error (%) ±300 24,3344,2184,904-14.0 47,1206,6766,4773.1 +500 22,5445,9606,223-4.2 34,7707,2486,8785.4 48,6688,7278,4083.8 +600 33,8166,232*7,445-16.3 47,1209,3038,7216.7 613,00218,354 *12,74344.0 +800 65,72411,02710,8681.5 510,83511,57012,248-5.5

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JWG-B2/B4/C1.17 caseDescription Tower Weight (kg) 1Base Case: increase 2m in the pole spacing 7,498 2Base Case: increase 3m in the tower height 7,579 3 Tower with V string, + 500 kV, 3xLapwing 9,7 4 Self supporting tower, + 500 kV, 3xLapwing, I string 15,6 5Only one shield wire, Base Case 7,749 6 Region with ice, 500 kV, 3xFalcon, guyed tower, I string 12,983 7Monopolar line, Base Case 6,38 8Metallic return by the shield 10,384 9Base Case: period return wind 500 years 10,454 10Base Case: cross-rope tower 7,878 11 BASE CASE ( + 500kV,3xLapwing, guyed, I string, non ice, bipolar, no metallic return, 2 shield wires) 7,248 Sensitivity

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JWG-B2/B4/C1.17 line material and labor. Engineering Design Topography Survey Environmental studies. Materials Tower Foundation conductor shield wire guy wire grounding (counterpoise) insulator conductor hardware shield wire hardware guy wire hardware spacer damping accessories Man labor ROW and access Tower erection Tower foundation erection Tower foundation excavation Guy wire foundation erection Guy wire foundation excavation Conductor installation Shield wire installation Guy wire installation Grounding installation Administration & Supervision material transportation to site inspection at manufacturer site construction administration. Contingencies. Taxes were considered separately from items above

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JWG-B2/B4/C1.17 Operation costs joule and corona losses, operation and maintenance electrode and electrode lines converter station staging

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JWG-B2/B4/C1.17 ITEMDESCRIPTION ±300kV ±500kV ± 600kV ±800kV 2 Kiwi4 Chukar2 Bittern 3 Lapwing4 Kiwi3 Bittern4 Chukar6 Kiwi6 Rail5 Kiwi MCM total433471202544477086683816712013002572410835 1Engineering % Engineering (design, topography, survey, environmental studies)4.793.444.573.952.943.863.042.062.882.19 2Materials % Tower, foundation, guy and hardware17.5316.4019.8419.2817.6620.2219.0119.0921.4520.16 Conductor30.9339.9618.529.8037.9823.2135.2739.8426.0735.33 Shield wire, insulator, grounding, cond & shield wire hardware,spacers, accessories4.534.084.704.635.174.454.615.105.615.15 Sub total materials52.9960.4442.8953.7160.8147.8858.8964.0353.1360.63 3Man labor % ROW and access15.059.8926.6315.9110.4522.4511.897.7316.7811.60 Tower, foundation and guy erection6.586.197.677.356.817.857.34 8.467.61 Conductor installation7.627.745.736.626.985.776.837.327.016.49 Shield wires and grounding installation3.292.363.142.722.022.652.081.411.981.50 Sub total man labor32.5426.1843.1732.6026.2638.7228.1523.8034.2327.20 4Administration & Fiscalization % Material transportation to site1.181.311.061.241.351.151.331.421.281.35 Inspection at manufacturer site3.714.233.003.764.263.354.124.483.724.24 Construction administration1.871.482.391.831.462.131.561.291.861.47 Sub total adm & fiscaliz6.767.026.456.837.076.637.017.196.857.06 5Contingencies % 2.9 6TOTAL U$/km (100%)155,719217,101163,273188,79253,618193,636245,952362,673259,063340,877 Table 4.56: Bipolar line costs parcels in percent (100% is the reference in Line 6 of the Table)

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JWG-B2/B4/C1.17 Curve fitting Cline = a + b V + S (c N + d) a, b, c, d are parameters obtained by curve fitting of the data V is the pole to ground voltage (kV) S is the conductor cross section (MCM) N is the number of conductor per pole. a = 69,950 b = 115.37 c = 1.177 d = 10.25

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JWG-B2/B4/C1.17 Figure 4. 29: Adjusted line costs (2X300: means 2 conductor and 300kV)

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JWG-B2/B4/C1.17 Table 4.58: Estimated bipolar transmission line costs, region I, in U$ kVconductorU$/km ±300 2x2,167 Kiwi 159,181 4x1780 Chukar 211,061 ±500 2x1,272 Bittern 159,691 3x1,590 Lapwing 193,365 4x2,167 Kiwi 257,291 ±600 3x1,272 Bittern 191,753 4x1,780 Chukar 245,671 6x2,167 Kiwi 364,272 ±800 5x954 Rail 261,337 5x2,167 Kiwi 337,072

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JWG-B2/B4/C1.17

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Table 4.59: Line cost sensitivity caseDescription Line cost U$/km % of Base Case 1For the Base Case increase 2m in the pole spacing 193,200101.0 2For the Base Case increase 3m in the tower height 193,900101.3 3Tower with V string, + 500 kV, 3xLapwing 217,100113.5 4Self supporting tower, + 500 kV, 3xLapwing 236,800123.8 5Only one shield wire, Base Case 192,200100.5 6Region with ice, + 500 kV, 3xFalcon 244,600127.8 7Monopolar line, Base Case 155,50081.3 8Metallic return by the shield wire 217,050113.4 9For the Base Case period return wind 500 years 215,660112.7 10For the Base Case cross-rope tower 194,600101.7 BASE CASE 191,328100

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JWG-B2/B4/C1.17 P is the rated bipole power MW V is the Voltage to ground kV r is the bundle resistance ohms/km r = ro L / S ro conductor resistivity 58 ohms MCM/ km L, S are the length and cross section in km and MCM Joule losses typical value 230 U$/kW alternative 15% lower

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JWG-B2/B4/C1.17 dB bipole losses in watt per meter corona loss go=25 kV/cm; do= 3.05 cm; no= 3 Ho=15 m; So=15 m; Po= 2.9 dB fair weather and 11 dB foul weather

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JWG-B2/B4/C1.17 Optimal Conductor (aluminum pole cross section) Cline = (0.02+ k)* (A + B S) S is the pole Aluminum area, k is the factor to convert Present Worth into yearly cost; 0.02 is a factor to consider operation and maintenance cost, Closses= C/S is the yearly cost of the losses. total yearly cost (Cty=Cline+Closses), Cty= A + B S + C/S minimum =>

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JWG-B2/B4/C1.17 Most Economical line for 6000 MW Table 4.64 Economic line for 6,000 MW kV + 600 + 800 cond/pole65 MCM (1)2,515 tot U$/yr/km101,47383,290 A) Most favorable solution – losses cost base case kV + 600 + 800 cond/pole64 MCM (1)2,5152515 tot U$/yr/km94,32178,154 B) Losses cost reduced by 15%

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JWG-B2/B4/C1.17 Impact of corona losses (800 kV line) solution desconsidering corona losses ** solution considering corona losses MW3,000 kV + 800 cond/pole44444 MCM 1,680* 1,800 **1,900 2,0002,200 tot U$/yr54,78954,70054,73054,83955,251 line U$/yr36,44237,43838,26839,09740,756 Joule U$/yr13,97013,03912,35211,73510,668 Corona loss U$/yr4,3774,2244,1104,0073,826

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JWG-B2/B4/C1.17 Table 5.1: Converter Station Costs voltage Bipolar Rating MW Cost U$/k W Total cost Million U$ Source 500 1,000170 [44] CIGRE Brochure 186 500 2,000145290 [44] CIGRE Brochure 186 600 3,000150450 [44] CIGRE Brochure 186 500 3,000420 [45] IEEE Power and Energy 500 4,000680[45] 600 3,000450-460[45] 800 3,000510[45] CONVETER STATION

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JWG-B2/B4/C1.17 Table 5.2: Costs of Converter Stations (Rectifier plus Inverter) obtained by JWG-B2.B4.C1.17 from manufacturers FOB prices without tax and duties. Bipolar Rating MW kV12 pulse Conv./pole Suggested Costs M U$ Costs M € 1750+300 Voltage Source Converter 165115 2750+3001 (6 pulse)*155108 3750+3001165115 4750+5001185129 51,500+3001265184 61,500+5001305212 73,000+5001425295 83,000+6001460320 93,000+8001505351 106,000+6002 parallel875608 116,000+8002 series965671 126,000+8002 parallel965671

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JWG-B2/B4/C1.17 Ct= A (VB) ( PC) Ct Millions U$ P bipole power in MW V pole voltage kV Table 5.3: Converter Station costs: Results and accuracy casekVMW Obtain ed Cost without * 6,000 MW DIF (%) with * 6,000 MW DIF (%) 1 300 7501651702,8135-18,0 2 500 7501851997,8153-17,2 3 300 1,500265250-5,8238-10,3 4 500 1,500305293-3,8269-11,7 5 500 3,0004204322,747312,7 6 600 3,0004504571,649510,0 7 800 3,000510501-1,85314,1 8 600 6,000875673-23,1870-0,6 9 800 6,000965737-23,7933-3,3 A=0,698A=0,154 B=0,317B=0,244 C=0,557C=0,814

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JWG-B2/B4/C1.17 Table 5.4:Cost Division Standard thyristor bipole with two terminals Standard Bipole [%] Valve Group22 Converter Transformer22 DC Switchyard and filter6 AC Switchyard and filter9 Control, protection, communication8 Civil, mechanics, works13,5 Auxiliary Power2,5 Project engineering, administration17 Total100

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JWG-B2/B4/C1.17 Figure 5.4: General single line diagram

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JWG-B2/B4/C1.17 Table 5.6: Typical Losses of one Converter Station Components No Load (Standby) Rated Load Filters: AC-Filters DC-Filters 4 % 0 % 4 % 0.1 % Converter Transformer, 1phase, 3 winding53 %47 % Thyristor Valves10 %36 % Smoothing Reactor0 %4 % Auxiliary Power Consumption Cooling System, Converter Valves Cooling System, Converter Transformer Air-Conditioning System Others 4 % 15 % 10 % 3 % 1 % 4 % 1 % Referred to rated power of one 2000 MW Bipole-Station 2,2 MW14 MW

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JWG-B2/B4/C1.17 Figure 5.8: Thyristor development

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JWG-B2/B4/C1.17 line currentLine VoltageRated PowerDiameter of wafer 2 kA±500 kV2,000 MW4’’ / 10.0 cm 3 kA±500 kV3,000 MW5’’ / 12.5 cm 3,125 kA±800 kV5,000 MW5’’ / 12.5 cm 3,75 kA±800 kV6,000 MW6’’ / 15.0 cm

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JWG-B2/B4/C1.17 Figure 5.11: Example of a ± 500 kV 12-Pulses Valve Tower Configuration

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JWG-B2/B4/C1.17 Figure 5.12 VSC converters and cables

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JWG-B2/B4/C1.17 Figure 5.13 Tapping using VSC

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JWG-B2/B4/C1.17 Figure 5.14 VSC with multi level converter

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JWG-B2/B4/C1.17 Current Return Electrode Line Metalic Return Eletrode

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JWG-B2/B4/C1.17 Electrode line and electrode converter capacitor and breaker Return by shield wires Current Return eletrodo de terra retorno metálico

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JWG-B2/B4/C1.17 Figure 1: Metallic Return through pole conductor

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JWG-B2/B4/C1.17 Figure 2: Bipole paralleling

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JWG-B2/B4/C1.17 Electrode Line in the same tower of the bipole separated line cables More than one bipole 1 electrode and different electrode lines different lines e different electrodes (Itaipu)

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JWG-B2/B4/C1.17 design criteria for electrode line: The line shall have more than one conductor as a failure of it cause bipole outage Choice of the number and type of insulators in a string, this depends on the voltage drop in the electrode line due to DC current flow during monopolar operation, the electrode length and the conductor selected dictate the choice. The pollution level in the electrode area has also an influence. A gap shall be provided to get arc extinction after fault in the electrode line to ground. The relative position of the electrode line as related to bipole is an important aspect as related to the electrode line insulation design. The electrode line tower grounding is an important aspect in order to limit the flashovers to ground (structure). An adequate clearance to ground has to be provided to comply with the current passing through and eventual loss of one of the conductor

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JWG-B2/B4/C1.17 Linha do Eletrodo

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JWG-B2/B4/C1.17 1.Electrode Line costs parcels in percent (100% are table ITEM 6 values) ITEMDESCRIPTION2xJoree2xLapwing4xLapwing4xRail MCM total5030318063603816 1Engineering % Engineering (design & topography.)2.192.841.742.38 2Materials % Poles and foundation12.2214.6112.5914.91 Conductor42.0935.5743.635.74 Insulatior,hardware & accessories, grounding2.533.282.323.17 sub total materials56.8453.4658.5253.83 3Man labor % ROW and access3.013.92.393.26 Pole erection7.167.3678.46 Conductor installation16.0516.7915.4416.34 Poles foundation excavation0.330.420.290.37 sub total man labor26.5528.4625.1128.43 4Administration & Fiscalization % material transportation to site6.097.016.287.14 inspection at manufacturer site3.983.744.13.77 construction administration1.441.571.341.54 sub total adm & fiscaliz11.5112.3211.7212.45 5Contingencies % 2.91 6TOTAL kU$/km (100%)68.3152.7286.0362.98

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JWG-B2/B4/C1.17 ELECTRODE LINE COST (US$/km) 40,000 50,000 60,000 70,000 80,000 90,000 3,0004,0005,0006,0007,000 Total Cross Section (MCM) COST (US$/km) 2 conductor 4 conductor

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JWG-B2/B4/C1.17 Power (MW)700 1500 3000 6000 Pole Voltage (kV)300500 600500600800600800 Pole Current (kA)1.170.701.501.253.002.501.885.003.75 Pole cond number223344465 MCM one cond.240019502,0171,6812,5152,4201,8152,515 MCM total480039006051504310060968072601509012575 current/conductor (kA)0.580.350.500.420.750.630.470.830.75 cond. Temp (oC)454045 5545 55 sag (m)19 Proposed electrode line design Electr. Line cond. number222222233 Electr. Line MCM12001033.51513126125152420181525152096 MCM tot240019503025.52521.550304840363075456287.5 curr/cond (A)1.170.700.750.631.501.250.941.671.25 Temp (oC)6555 7065607565 sag (m)20.5 Elect. Line Voltage drop and losses kV/km0.0280.0210.029 0.0350.030 0.0380.035 losses MW/km0.0330.0150.0430.0360.1040.0750.0560.1920.130 kV for 50 km (elect line)1.411.041.44 1.731.50 1.921.73 losses two 50 km elect lines (MW)3.291.464.313.5910.387.495.6219.2212.97 Metallic return through pole kV/km0.0140.0100.014 0.0170.015 0.0190.017 Return cond. losses (%) for 3000 km-3.14.33.65.23.72.84.83.2 kV for 1000 km (metallic ret.)14.110.414.4 17.315.0 19.217.3 kV for 1500 km(metallic ret.)21.115.621.6 25.922.5 28.825.9 kV for 3000 km(metallic ret.)42.331.243.1 51.944.9 57.751.9 Metallic return by shield wire kV/km0.0280.0210.029 0.0350.030 0.0380.035 Return cond. losses (%) for 3000 kmNA 8.67.210.47.55.69.66.5 Electrode and metallic return lines design

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JWG-B2/B4/C1.17 Electrode Design Full current 2.5% of the time; 2.5% of unbalance current permanently. Potential gradient and step voltage at electrode site; Current density to avoid electro-osmosis in the anode operation; Touch voltages to fences, metallic structures and buried pipes nearby; Corrosion of buried pipes or foundations; Stray current in power lines, especially via transformer neutrals; Stray current in telephone circuits.

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JWG-B2/B4/C1.17 Figure 6.5: Ground surface potential as a function of distance from electrode center

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JWG-B2/B4/C1.17

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h carvão condutor ferro 9000 kg/ano com corrente de 1000A (15 a 25 A/m 2 ); grafite 60%do ferro

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JWG-B2/B4/C1.17 Table 6.4: One electrode cost item% Materials buried wire8.0 coke13.8 connections house1.6 sub total materials23.5 Man labor73.6 Engineering - contingencies- land 2.9 Materials taxes9.4 Man labor taxes7.4 Total cost (100%) U$ 483,000 U$

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JWG-B2/B4/C1.17 Cline = a + b V + S (c N + d) a, b, c, d are parameters obtained by curve fitting of the data V is the pole to ground voltage (kV) S is the total conductor cross section (MCM) N is the number of conductor per pole. System Economics a = 69,950 U$/km b = 115.37 U$/kV c = 1.177 d = 10.25

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JWG-B2/B4/C1.17 P is the rated bipole power MW V is the Voltage to ground kV r is the bundle resistance ohms/km r = ro L / S ro conductor resistivity 58 ohms MCM/ km L, S are the length and cross section in km and MCM Joule losses typical value 230 U$/kW alternative 15% lower

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JWG-B2/B4/C1.17

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optimal Conductor (aluminum pole cross section) Cline = (0.02+ k)* (A + B S) S is the pole Aluminum area, k is the factor to convert Present Worth into yearly cost; 0.02 is a factor to consider operation and maintenance cost, Closses= C/S is the yearly cost of the losses. total yearly cost (Cty=Cline+Closses), Cty= A + B S + C/S minimum =>

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JWG-B2/B4/C1.17 Three conditions may occur Sec conductor is to large for N subconductor configuration adopt Nx2515 Sec conductor is too small adopt configuration to get 28 kV/cm surface grad Sec conductor is Ok adopt the Sec configuration NO alternative is descarded

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JWG-B2/B4/C1.17 Station Cost For power rating up to 4000MW, one converter per pole: a = 106*0.698*1.5 (1.5 is a factor to include taxes in Brazil, for every country a specific value should be used); b = 0.317; c = 0.557; For power rating above 4000 MW (2 series converters per pole) a = 106*0.154*1.5 (1.5 is a factor to include taxes in Brazil); b = 0.244; c = 0.814 Yearly cost including maintenance Cstaty = 1.1 * ( 0.02+ k) * Ccs

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JWG-B2/B4/C1.17 a) power < 2,500 MW b) power from 2,500 to 6,000 MW Figure 7.1: Yearly total cost as a function of power and voltage for 750 km line

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JWG-B2/B4/C1.17 a) power < 2,500 MW b) power from 1,500 to 6,000 MW Figure 7.2: Yearly total cost as function of power and voltage for 1,500 km line

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JWG-B2/B4/C1.17 a)power < 2,500 MW a)power from 1,500 to 6,000 MW Figure 7.3: Yearly total cost as function of power and voltage for 3,000 km line

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JWG-B2/B4/C1.17 Figure 7.4: Optimal voltages as a function of power and length Legend: Red → ±800 kV; green → ±600 kV; pink → ±500 kV; blue → ±300 kV

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JWG-B2/B4/C1.17 MW7001,5003,0004,5006,000 kV+300+500+600 +800 N x MCM2X2,2802X2,5154X2,2425X2,515 MU$/yr% % % % % line67,453,579,544,1113,743,0142,338,6151,935,6 corona3,83,09,55,28,23,16,21,78,42,0 joule23,919,035,819,955,821,189,624,389,621,0 converter30,924,555,630,886,732,8130,635,4177,041,5 U$/year126,1100,0180,4100,0264,5100,0368,7100,0426,9100,0 Figure 7.7: Cost Parcels, 3,000 km line

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JWG-B2/B4/C1.17 Calculations Considering Cost Components Allocated in Different Years

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JWG-B2/B4/C1.17 Table 7.6: Comparison between ± 600 kV and ± 800 kV

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JWG-B2/B4/C1.17 4.2 Study Case 2: As Basic Case; P taking 4 years to reach 3000MW

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JWG-B2/B4/C1.17

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CIGRE Brochure 178 “Probabilistic Design of Overhead Transmission Lines”, CIGRE Brochure 48 “Tower Top Geometry”, CIGRE Brochure 109 “Review of IEC 826: Loading and Strength of Overhead Lines” CIGRE Brochure 256 “Report on Current Practices Regarding Frequencies and Magnitude of High Intensity Winds”, IEC/TR 60 826 Loading and Strength of Overhead Transmission Lines CIGRE “Brochure 207 Thermal Behavior of Overhead Conductors” Gilman D W; Whitehead E R “The mechanism of Lightning Flashover on HV and EHV Transmission Lines”, Electra no 27, 1975

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