25 kV Equipment Sizing Calculationv5_ (1).pdf

.

DESIGN OF 25 KV OVERHEAD EQUIPMENT (OHE) SYSTEM FOR ELEVATED

LINES AND POWER SUPPLY & SCADA

FOR BOTH UNDERGROUND AND ELEVATED LINES INCLUDING CHECKING OF

DESIGN OF

RECEIVING SUBSTATION

AND DESIGN VALIDATION OF DELHI MRTS PHASE III PROJECT LOT I

25 KV TRACTION EQUIPMENT SIZING

CALCULATIONS

January, 18th 2013

.

25 KV Traction Equipment Sizing Calculations

CONTENTS

1. INTRODUCTION ..................................................................................................................... 4

1.1. Reference documentation ................................................................................................ 4

1.2. Abbreviations ................................................................................................................... 5

2. TRACTION TRANSFORMERS .............................................................................................. 6

2.1. Power consumption of TSSs ........................................................................................... 6

2.1.1. Normal operation (5 traction substations working) .................................................... 6

2.1.2. Failure cases .............................................................................................................. 7

2.2. Voltage in pantograph .................................................................................................... 11

2.2.1. Normal operation (5 traction substations working) .................................................. 11

2.2.2. Failure cases ............................................................................................................ 12

2.3. Conclusions .................................................................................................................... 13

3. BOOSTER TRANSFORMERS ............................................................................................. 15

4. 25 KV FEEDERS .................................................................................................................. 19

4.1. Rated current calculation (In) ......................................................................................... 19

4.1.1. Main track ................................................................................................................. 19

4.1.2. Depot Calculation ..................................................................................................... 20

4.2. Calculation with current in case of nominal overload of the transformer (Io) ................. 21

4.3. Voltage drop ................................................................................................................... 23

4.4. Short circuit criteria ........................................................................................................ 23

4.4.1. Simply Single Line Scheme ..................................................................................... 25

4.4.2. Equivalent Single Line Scheme ............................................................................... 25

4.4.3. Impedance Calculations ........................................................................................... 26

4.4.4. Calculation of the continuous current of short circuit (Isc) ....................................... 28

4.4.5. Calculation of the Maximum Current Asymmetric Short-Circuit (Is) ........................ 28

4.4.6. Rupture capacity and connection ............................................................................. 29

4.5. Conductor sizing ............................................................................................................ 29

4.5.1. Type of Conductor .................................................................................................... 29

4.5.2. Size of Conductor ..................................................................................................... 30

5. RETURN CABLES................................................................................................................ 35

5.1. Return cables ................................................................................................................. 35

5.2. Return conductor ............................................................................................................ 35

5.2.1. Rated current calculation (In) ................................................................................... 35

5.2.2. Voltage drop ............................................................................................................. 36

5.2.3. Short circuit criteria .................................................................................................. 36

6. INDUCED VOLTAGE CALCULATION ................................................................................ 36

7. CIRCUIT BREAKERS RATING ............................................................................................ 38

.


8. INTERRUPTERS RATING ................................................................................................... 39

9. CURRENT TRANSFORMERS RATING .............................................................................. 40

Annex 1. Technical data of 26/45 kV XLPE insulated copper cable used for

calculation.

Annex 2. Guide for calculation of cable capacity under short time operation

currents.

Annex 3. Technical data of aluminium cables used for calculation.

Annex 4. Rolling stock data used for calculation

25 KV Traction Equipment Sizing Calculations 4

1. Introduction

The present document aims to determine the rating of the equipment foreseen for the 25 kV

traction network in the scope of the design of 25 kV Overhead Equipment (OHE) system for

the Mukundpur Gokulpuri Shiv Vihar section (Line 7) including Mukundpur and Vinod

Nagar Depots.

1.1. Reference documentation

Comparative Study of various Schemes of underground ASS & Recommendations

for DMRC Phase-III.

DMRD. Edition Nov 2011.

Ardanuy-Barsyl. Edition of 17/08/2012

DMRC Project Line 7. Detail Design Consultant. CCDD-1. Traction simulation sizing

study

Ardanuy-Barsyl. Edition of 17/08/2012


1.2. Abbreviations

DMRC Delhi Metro Rail Corporation Limited

UG Underground (Package, Station or Section)

ELV Elevated (Package, Station or Section)

DPT Depot

ASS Auxiliary Substation

RSS Receiving Substation

TSS Traction Substation

PD Propriety Development

TVF Tunnel Ventilation Fan

TEF Tunnel Emergency Fan

ECS Environment Control System

S&T Signal & Telecommunication

TR Transformer

DG Diesel Generator

CCB Coupling Circuit Breaker

VDE Association of German Electrical Engineers


2. Traction Transformers

The Traction Simulation Study for the Line 7 extension has been performed by M/s Ardanuy

using RailPower software.

In this chapter the results and main conclusions obtained from the study are included.

2.1. Power consumption of TSSs

Different alternatives have been simulated to get the power consumptions in transformers of

the Tractions Substations. The values have been obtained taking into account these

assumptions:

Total Trip: Mukundpur Shiv Vihar, 57.705 km, 37 stations.

Rolling Stock with 6 coach compositions (DM-T-M-M-T-DM) and full loaded (1,800

people). Total weight of Rolling Stock is 371.25 Tons (Tare weight is 252 Tons, 42

Tons/car).

It is assumed that up to 75% of the power generated by train braking is able to be

regenerated in electrical power by the motors of the train (Regenerative braking

performance will be 0.75).

Braking force will be supplied by the train motor brakes until the maximum engine

brake force for each speed is given. If it is necessary more braking force than the

motor is able to generate, it will be provided by pneumatic brake.

By default, it is considered a value of train power factor of 1.

Auxiliary Power Consumption of trains (according to values provided by DMRC): 33

kVA/car (198 kVA whole train)

Headway of 135 seconds between trains in same direction (what means 68 trains at

same time in the system)

2.1.1. Normal operation (5 traction substations working)

Maximum, average and RMS (maximum RMS value for integration period of 1 hour) power

values for Traction Substations during the peak hour are shown in the following table.


SIMULATED VALUES OF POWER CONSUMPTION IN TSS

MKPR (KVA)

DH-KN INA VN-NG YMVH

(KVA) (KVA) (KVA) (KVA)

TRF1 TRF1 TRF1 TRF1 TRF1

MAX 19.630 37.103 24.233 32.028 19.422

RMS 12.114 17.219 16.388 17.006 12.625

AVG15 min. 11.146 13.556 15.625 14.875 10.773

AVG5 min. 11.478 14.640 16.072 15.431 11.067

Table 1. Simulated values of power consumption in TSS. Normal operation

According to these values, transformers with nominal power of 40/50 MVA are plenty

dimensioned to feed the whole line present.

The overload conditions that each transformer should be complied are:

Overloads above 150% of nominal power (40 MVA) during less than 15 minutes in a

3 hour cycle.

Overloads above 200% of nominal power (40 MVA) during less than 5 minutes in a 3

hour cycle.

It can be seen the worst case (transformer more loaded) for this simulation is transformer of

Dhaula Kuan TSS. There is not any instant in the simulation when the power is higher than

150% of nominal power (40x1,5 = 60 MVA), therefore both conditions of overloading are

complied.

2.1.2. Failure cases

Feed extensions cases have been simulated, for failures of 1, 2, 3 and 4 TSS. The worst

case for each type of operation (N-1, N-2, N-3 and N-4) has been simulated.

The following list shows the worst case simulated for each operation mode (the worst case

for each operation mode is the case where the electrical sector fed by 1 TSS is the longest):

N-1 Case. Failure of TSS3 (INA): Dhaula Kuan will feed from Neutral Section in K.P

9+200 to Neutral Section in 34+935.

N-2 Case. Failure of TSS1 (Mukund Pur) and TSS2 (Dhaula Kuan): INA will feed

from dead end of the line (Mukund Pur Station) to K.P. 34+845.


N-3 Case. Failure of TSS1 (Mukund Pur), TSS2 (Dhaula Kuan) and TSS3 (INA):

Vinod Nagar will feed from dead end of the line (Mukund Pur Station) to K.P. 48,685.

N-4 Case. Failure of TSS2 (Dhaula Kuan), TSS3 (INA), TSS4 (Vinod Nagar) and

TSS5 (Yamuna Vihar): Mukund Pur will feed the whole line

Simulations for feed extension cases have been realized taking into account the following

headways:

Case Headway.

Case N-1 135 seconds



Case N-4 1,200 seconds

Table 2. Headway for failure cases

CASE N-1: FAILURE OF TSS3 (INA)

In this case, Dhaula Kuan will be feeding from Neutral Section in K.P 9+200 to Neutral

Section in 34+935. The rest of the line will be fed as normal operation case.

FAILURE OF INA TSS

-0+680 MKPR

TSS

9+200 SP

17+045 DH-KN

TSS

34+935 SP

42+140VN-NG

TSS

48+775 SP

54+000YMVH

TSS

Figure 1 Case N-1. Failure of TSS3 (INA)


MKPR (KVA)

DH-KN (KVA)

VN-NG (KVA)

YMVH (KVA)

TRF1 TRF1 TRF1 TRF1

MAX 19.630 54.085 32.028 19.422

RMS 12.114 31.826 17.006 12.625

AVG15 min. 11.146 28.252 14.875 10.773

AVG5 min. 11.478 29.627 15.431 11.067

Table 3. Simulated values of power consumption in TSS. Case N-1


The worst case for this simulation is the transformer of Dhaula Kuan TSS. In order to comply

with criteria of overload above 150% during less than 15 minutes in a 3 hours cycle, the

nominal power of this transformer will be dimensioned for 40 MVA.

CASE N-2: Failure of TSS1 (Mukund Pur) and TSS2 (Dhaula Kuan)

In this case, headway of 4 minutes has been taken into account. INA will be feeding from

dead end of the line (Mukund Pur Station) to K.P. 34+845. The rest of the line will be fed as

normal operation case.

FAILURE OF MUKUND PUR AND DHAULA KUAN TSS

25+400 INA

TSS

34+935 SP

42+140VN-NG

TSS

48+775 SP

54+000YMVH

TSS

Figure 2. Case N-2. Failure of TSS1 (Mukundpur) and TSS2 (Dhaula Kuan)


INA VN-NG YMVH

(KVA) (KVA) (KVA)

TRF1 TRF1 TRF1

MAX 52.217 15.360 16.613

RMS 26.356 11.453 8.412

AVG15 min. 23.080 9.207 6.581

AVG5 min. 25.082 10.494 7.366


The worst case for this simulation is the transformer of INA TSS. In order to comply with

criteria of overload above 150% during less than 15 minutes in a 3 hours cycle, the nominal

power of this transformer will be dimensioned for 40 MVA.

CASE N-3: Failure of TSS1 (Mukund Pur), TSS2 (Dhaula Kuan) and TSS3 (INA)

In this case, headway of 8 minutes has been taken into account. Vinod Nagar will be feeding

from dead end of the line (Mukund Pur Station) to K.P. 48,685. The rest of the line will be fed

as normal operation case.


FAILURE OF MUKUND PUR AND DHAULA KUAN AND INA TSS

42+140VN-NG

TSS

48+775 SP

54+000YMVH

TSS

Figure 3. Case N-3. Failure of TSS1 (Mukundpur), TSS2 (Dhaula Kuan) and TSS3 (INA)


VN-NG YMVH

(KVA) (KVA)

TRF1 TRF1

MAX 34.550 10.473

RMS 19.605 4.864

AVG15 min. 16.523 3.668

AVG5 min. 17.910 4.201


The worst case for this simulation is the transformer of Vinod Nagar TSS. In order to comply

with criteria of overload above 150% during less than 15 minutes in a 3 hours cycle, the

nominal power of this transformer will be dimensioned for 40 MVA.

CASE N-4: Failure of TSS2 (Dhaula Kuan), TSS3 (INA), TSS4 (Vinod Nagar) and TSS5

(Yamuna Vihar)

In this case, headway of 20 minutes has been taken into account. Mukund Pur will be

feeding the entire line.

FAILURE OF DHAULA KUAN, INA, VINOD NAGAR AND YAMUNA VIHAR TSS

-0+680 MKPR

TSS

Figure 4. Case N-4. Feeding from TSS1 (Mukundpur)


POWER CONSUMPTION IN TSS

MKPR (KVA)

TRF1

MAX 22.458

RMS 10.910

AVG15 min. 8.854

AVG5 min. 9.768


In order to comply with criteria of overload above 150% during less than 15 minutes in a 3

hours cycle, the nominal power of the Mukumpur SST transformer will be dimensioned for 40

MVA.

2.2. Voltage in pantograph

2.2.1. Normal operation (5 traction substations working)

Voltage in the train pantographs have been calculated considering Normal Operation of

electrification system (5 Traction Substations working at same time).

For this calculation the following has been taken into account:

Value of lump impedance of the catenary system

25 kV feeding cable impedance

Exit voltage at the electrical traction substations

Exit current at the substations

Current consumed by each train, which will correspond to the results of the

simulations

Location of the substations and neutral sections

The voltages presented below are the maximum and minimum that can be produced on the

pantograph with the foreseeable circulation graph (headway of 135 seconds).


VOLTAGE IN TRAIN PANTOGRAPH

DIRECTION MIN

(V)

MAX

(V)

AVG

(V)

MUKUNDPUR SHIV VIHAR 26,563 27,939 27,332

SHIV VIHAR - MUKUNDPUR 26,517 28,150 27,341

Table 7. Voltage in train pantograph. Normal operation

For normal operation, minimum voltage in the line is 26,517 V, over the threshold

established in the normative EN 50163 Railway applications - Supply voltages of traction

systems, for traction systems of AC 25 kV (Umin1 = 19,000 V).

2.2.2. Failure cases

Except in the case of N-1, the headway between trains should increase as shown below to

assure that the voltage drop in the pantograph trains complies with the values established in

norm EN 50163 (where Umin1 = 19,000 V):

Case Headway.

Case N-2 4 minutes

Case N-3 8 minutes

Case N-4 20 minutes

Table 8. Headway for N-2, N-3 and N-4 failure cases.

In the following table, values of voltage in the train pantographs are shown for the different

cases of feed extensions.


CASE DIRECTION MIN (V) MAX (V) AVG (V)

CASE N-1: FAILURE TSS3

FEED FROM TSS2

DW LINE 25,550 27,939 27,138

UP LINE 25,681 28,150 27,134

CASE N-2: FAILURE TSS1 AND TSS2

FEED FROM TSS3

DW LINE 19,737 28,054 26,979

UP LINE 22,859 28,333 27,084



CASE DIRECTION MIN (V) MAX (V) AVG (V)

CASE N-3: FAILURE TSS1,TSS2 AND TSS3

FEED FROM TSS4

DW LINE 20,159 28,082 26,691

UP LINE 23,337 28,130 26,800

CASEN N-4: FAILURE TSS2, TSS3, TSS4 AND

TSS5

FEED FROM TSS1

DW LINE 20,478 28,535 26,668

UP LINE 21,027 28,420 26,615

Table 9. Voltage in train pantograph. Failure cases

In N-1 situation, the minimum value of voltage in train pantograph is 25,550 V. This value is

over the threshold established in the normative EN 50163 (where Umin1 = 19,000 V)







2.3. Conclusions

Main conclusions obtained for the study are summarized below:

From electrical simulations, it can be deduced that 40/50 MVA transformers are

sufficiently dimensioned to support headway of 135 seconds with the model of train

considered and the 5 substations working at normal operation.

There are no overloads exceeding 50% in any of the transformers of 40/50 MVA

(nominal power value).

From the simulations of failure of one of the Traction Substations (feed extensions

cases) it can be deduced for the worst case will be failure of INA TSS. In this case

the transformers of 40/50 MVA (Dhaula Kuan TSS) comply with the criteria of

overload.

With respect to drop voltage along the line, for cases simulated the voltages in train

pantographs are over the threshold established in the normative EN 50163 Railway

applications - Supply voltages of traction systems (where Umin1 = 19,000 V)


From the simulations of failure of more than 1 Traction Substation (feed extension N-

2, N-3 and N-4) headway must be increased in order to reduce the number of trains

and therefore maximum drop voltage along the OCS will be reduced complying with

the values established in norm EN 50163 (where Umin1 = 19,000 V).

With these operation conditions and headways, it can be deduced that for the worst

cases that all transformers will be plenty dimensioned for 40/50 MVA.


3. Booster Transformers

Currently, in existing lines of DMRC there are two kinds of Booster Transformers, with the

following characteristics:

Nominal Rating 150 kVA 280 kVA

Rated Current and

voltage

366 A at 409 V 500 A at 560 V

Overload rating (15 ms) 550 A 750 A

Impedance at full load at

75 Centigrade

0.15 ohm (Max) 0.15 ohm (Max)

Guaranteed max no load

losses

225 W 350 W

Guaranteed max load

losses

4000 W 6500 W

Table 10. Booster transformers used in DMRC

The maximum current calculated for outgoing feeders for the main line in Line 7 is 439.58 A

according to the electrical dimensioning of the Line 7 simulated with RailPower. This value

of current is the RMS value corresponding to n-2 failure situation (Mukundpur TSS and

Dhaula Kuan TSS failure) for the feeder cable to Down Line at Mukundpur side.

Capacity of booster transformers will be calculated with the expression:

BTRCBT UIS

Where:

SBT = Capacity of the booster transformer (VA).

UBT = Voltage in the booster transformer (V).

IRC = Return current which cross the booster transformer (A)

= Performance of the Booster transformer


Figure 5. Scheme of operation with Booster transformers

Considering that the voltage of the return conductor in the connection with rails is zero, the

voltage of the booster transformer can be calculated according to the expression:

)( BTRCRCRCBT zLzIU

Where:

UBT = Voltage in the booster transformer (V).

IRC = Return current which cross the booster transformer (A)

ZRC = Impedance per km of the return conductor (ohm/km)

LRC = Length of return conductor between the adjacent connections of RC with the

rail (km).

ZBT = Impedance of the booster transformer (ohm)

Calculating these parameters:

IRC (A) 439.58 From electrical dimensioning of the Line 7

(Maximum RMS value of case N-2)

0.85 Typical value

ZRC (ohm/km) 0.119+j0.402 Calculated from catalogue

LRC (km) 2.6 Maximum distance between two adjacent RC to rail

connections

ZBT (ohm/km) 0.016+j0.078 According calculated in annex 2 of Traction

Simulation Sizing Study

UBT (V) 514.12 Calculated with previous data

Sa (kVA) 265.92 Calculated with previous data

Table 11. Sizing of BT

Therefore, the Booster transformer of 280 kVA can be selected for the worst case.

Nevertheless, taking into account the location of every BT along the line (distance to TSS)

and the distances between adjacent BTs, and considering that every TSS feed the line with


this value maximum of current, these parameters can be calculated for every booster

transformer and therefore, accurate sizing of every booster transformer can be done.

In the following table these calculations are shown:

BT Ch. imp. Return

feeder (ohm/km)

imp. BT (ohm)

distance connection

rail-RC (km)

RC current

(A)

RC Voltage

(V) (BT

Voltage)

BT Power (kVA)

BT Power (kVA)

BT701 0+214 0.119+0.402i 0.016+0.078i 0.797 369.55 152.82 66.44 150

BT703 6+855 0.119+0.402i 0.016+0.078i 1.465 74.08 51.36 4.48 150

BT705 8+570 0.119+0.402i 0.016+0.078i 1.428 58.28 39.51 2.71 150

BT707 9+710 0.119+0.402i 0.016+0.078i 1.793 28.58 23.74 0.80 150

BT709 12+155 0.119+0.402i 0.016+0.078i 1.909 165.58 145.66 28.37 150

BT711 16+790 0.119+0.402i 0.016+0.078i 1.835 425.29 360.84 180.55 280

BT713 19+289 0.119+0.402i 0.016+0.078i 1.822 240.18 202.48 57.21 150

BT715 20+433 0.119+0.402i 0.016+0.078i 1.352 138.53 89.49 14.58 150

BT717 34+127 0.119+0.402i 0.016+0.078i 1.425 38.01 25.72 1.15 150

BT719 36+700 0.119+0.402i 0.016+0.078i 2.287 107.68 111.77 14.16 150

BT721 38+700 0.119+0.402i 0.016+0.078i 2.270 229.70 236.83 64.00 150

BT723 41+240 0.119+0.402i 0.016+0.078i 2.475 384.67 429.67 194.45 280

BT725 43+650 0.119+0.402i 0.016+0.078i 2.158 339.54 334.06 133.45 150

BT727 45+555 0.119+0.402i 0.016+0.078i 2.084 213.33 203.32 51.03 150

BT729 47+818 0.119+0.402i 0.016+0.078i 2.273 63.40 65.44 4.88 150

BT731 50+100 0.119+0.402i 0.016+0.078i 2.066 111.47 105.40 13.82 150

BT733 51+950 0.119+0.402i 0.016+0.078i 2.103 267.11 256.65 80.65 150

BT735 54+305 0.119+0.402i 0.016+0.078i 2.453 403.94 447.38 212.61 280

BT737 56+855 0.119+0.402i 0.016+0.078i 1.729 105.98 85.21 10.62 150

Table 12. Detailed calculation of Line 7 BTs (Up line)


According to these calculations it can be sized the booster transformers:

Up line Dn line

Booster

Transformer Capacity (kVA)

Booster

Transformer Capacity (kVA)

BT701 150 BT702 150

BT703 150 BT704 150

BT705 150 BT706 150

BT707 150 BT708 150

BT709 150 BT710 150

BT711 280 BT712 280

BT713 150 BT714 150

BT715 150 BT716 150

BT717 150 BT718 150

BT719 150 BT720 150

BT721 150 BT722 150

BT723 280 BT724 280

BT725 150 BT726 150

BT727 150 BT728 150

BT729 150 BT730 150

BT731 150 BT732 150

BT733 150 BT734 150

BT735 280 BT736 280

BT737 150 BT738 150

Table 13. Line 7 BTs (Up and down lines)


4. 25 kV Feeders

Dimensioning of 25 kV feeders has been developed according to the worst criterion of

following ones:

Maximum admissible current for conductors will be taken into account in order to

select the cable according to the maximum calculated current in normal conditions.

Voltage drop will be calculated in order to maintain minimum voltage above the

minimum voltage required for operation, which is 19 kV, according to EN.

Conductors must withstand mechanical and thermal loads during a short circuit.

Firstly, the value of currents foreseen in all of these cases is calculated. With all of these

values of currents, the size of the conductors which compose the feeders are checked.

4.1. Rated current calculation (In)

4.1.1. Main track

The maximum current calculated for feeding of the main line in Line 7 can be obtained from

Power Consumption Assessment for the electrical dimensioning of the Line 7: Mukundpur

Shiv Vihar. According to results given by the software, the worst case regarding currents is

when Mukundpur TSS and Dhaula Kuan TSS fail. In such case, INA TSS must feed the

section fed by these two substations in normal operation.

FAILURE OF MUKUND PUR AND DHAULA KUAN TSS

25+400 INA

TSS

34+935 SP

42+140VN-NG

TSS

48+775 SP

54+000YMVH

TSS

Figure 6. Worst case from the current values point of view. Case N-2.

In this case, according to the results given by the software, the currents in each outgoing

feeder from Mukundpur substation are:

Case F1 DOWN LINE F1 UP LINE F2 DOWN LINE F2 UP LINE

AVG 353.69 339.30 162.07 86.84

RMS 439.58 384.58 192.75 160.73

MAX 1152.14 774.55 364.55 349.99

Table 14. Current in feeder cables obtained in Traction Simulation Study in case N-2


Where F1 are the feeders which feed the Mukundpur side and F2 are the feeders which feed

the Shiv Vihar side of OHE.

Therefore, the feeders must be sized for an In of 439.58 A.

In the chapter 4.5 the conductors of feeders are sized according to this value of

current.

4.1.2. Depot Calculation

For Depot, the following cases have been considered:

Starting up of one train.

Several trains in stabling tracks consuming auxiliary power (33% of trains stabled in

depot).

The maximum current obtained between these two situations will be considered for sizing

the feeder cables from TSS to Depot.

Current in the starting up

For the starting up of the trains, the maximum current consumed by one train is 240 A

according to rolling stock data received (annex 4). It is considered that only one train is

starting up at depot at the same time.

Current because of auxiliary power consumption

The power required by auxiliaries of the rolling stock (6 cars) is 198 kVA.

In Mukundpur Depot there are 18 stabling track with capacity for 36 trains formed by 6 cars.

Considering that 33 % of the trains will be consuming maximum power at the same time, the

current through the feeder will be:

minn

a

nU

SnI

Where:

n = number of trains consuming auxiliary power at the same time

Sa = apparent power of auxiliaries of the rolling stock (6 cars) in kVA.

Unmin = minimum admissible voltage in kV.


Unmin (kV) 19 Minimum admissible voltage

n 12 33% of total capacity of stabling tracks

Sa (kVA) 198 According to Rolling Stock data

In (A) 125.05 Calculated with previous data

Table 15. Current in feeder cable in Mukundpur Depot.

Case of 12 trains with auxiliary power consumption

In Vinod Nagar Depot there are 45 stabling track with capacity for 45 trains formed by 6 cars.

Considering that 33 % of the trains will be consuming maximum power at the same time, the

current through the feeder will be:

minn

a

nU

SnI

Where:

n = number of trains consuming auxiliary power at the same time

Sa = apparent power of auxiliaries of the rolling stock (6 cars) in kVA.

Unmin = minimum admissible voltage in kV.

Unmin (kV) 19 Minimum admissible voltage

n 15 33% of total capacity of stabling tracks

Sa (kVA) 198 According to Rolling Stock data

In (A) 156.31 Calculated with previous data

Table 16. Current in feeder cable in Vinod Nagar Depot.

Case of 15 trains with auxiliary power consumption

Therefore the maximum current considered to size the feeder cable to Mukundpur and to

Vinod Nagar Depot will be given by the starting up of train case.

In the chapter 4.5 the conductors of feeders are sized according to these values of

current.

4.2. Calculation with current in case of nominal overload of the transformer (Io)

In the previous chapter, the nominal current in the worst case of overload has been

determined according to results given by Power Consumption Assessment.

However, traction transformers must have an overloading capacity of traction transformer of

50%loading for 15 minutes and 100% overloading for 5 minutes, after the transformer has

attained steady temperature on continuous operation at full load, with interval between two

successive overloading of 3 hours.


Therefore, in case of the maximum overload of the transformer, the current will be bigger

than obtained by calculations, because the transformer capacity has been selected in order

to fulfill this overloading requirement.

Taking this into account, the capacity of the transformer considered for calculations must be

of 40 MVA.

The maximum current given by the transformer in overload situation can be obtained by:

n

oo

U

SI

With:

So = apparent power in kVA in 50% and 100% overload.

Un = nominal voltage in kV.

Therefore, the currents will be:

Un (kV) 25 25

Sn (kVA) 60000 80000

In (A) 2400 3200

Table 17. Currents given by traction transformer in overload cases

These currents will pass through 4 feeders existing in the substation (up and down,

Mukundpur and Shiv Vihar sides). The quantity of the total current which goes for every

feeder will not be the same. To make the calculation, the same percentages which have

been obtained in the Power Consumption Assessment calculation have been considered. In

the case of failure n-2, these percentages are:

RMS %

F1 DN 439.58 37%

F1 UP 384.58 33%

F2 DN 192.75 16%

F2 UP 160.73 14%

Table 18. RMS values of current in every feeder cable of INA TSS. N-2 case

Taking these percentages into account, the most loaded feeder in the overload situation will

take the 37% of the total current. Therefore, the feeder must be dimensioned for withstand

888 A during 15 minutes and 1184 A for 5 minutes.


In the chapter 4.5 the conductors of feeders are sized according to these values of

current.

4.3. Voltage drop

Voltage drop calculated in Traction Simulation Study for Line 7 has already into account the

length of the feeders which feed main tracks from TSSs. Therefore, they are suitable

according to this criterion.

Regarding feeder to Depots, voltage drop must be calculated according to expression:

XjRILU

Where:

L = Length of the conductor (km)

I = Current of the conductor (A)

R = conductor resistance ( /km)

X = conductor reactance ( /km)

The voltage drop will be:

Feeder Mukundpur Depot Vinod Nagar Depot

L (km) 1.2 1.7 Distance from drawings

I (A) 240 240 From chapter 4.2

R (/km) 0.0754 0.0754 Calculated from catalogue

X (/km) 0.115 0.115 Calculated from catalogue

U (V) 39.60 56.10 Calculated with previous data

Table 19. Voltage drop calculation for feeder cables in depots

4.4. Short circuit criteria

When sizing and selecting equipment, and electrical components must be taken into account

in accordance with VDE (Association of German Electrical Engineers) determinations, not

only due to permanent loads the current and voltage, but surges caused by short circuits.

Short-circuit currents are usually several times higher than nominal therefore cause high

dynamic and thermal overloads. The short circuit currents traversing land can also be the

cause of contact stresses and unacceptable interference. Short circuits can cause the

destruction of equipment and components or cause damage to people if the design does not

take into account the maximum short-circuit currents.


For calculation of short circuit currents will follow the guidelines VDE 0102, and 2/11.75

1/11.71 parts.

Two methods exist to perform the calculation, one, the absolute impedance calculation, and

the other, the dimensionless impedance calculation or per unit. It has been selected the

calculation per unit method for this design.

The per unit method simplifies the calculation when there are two or more levels of voltage

and interest the effective value. It also presents other advantages:

Manufacturers specify the impedances in percent of the nominal values given in the

plates.

The impedances per unit of the same type of apparatus are very close values,

although their ohmic values are very different. If you do not know the impedance of a

device, you can select from tabulated data that provide reasonably accurate values.

The impedance of a transformer unit is equal in the primary than in the secondary

and is not dependent on the type of connection of the windings.

To follow the method per unit must establish two arbitrary values, such condition all others.

Normally the base values chosen are:

A [MVA] power for the entire circuit

B [kV] to a voltage level

For a different voltage level, the voltage value of the base has to be multiplied by the

transformation ratio of the transformer which separates the two levels.

In calculating circuit currents requires knowledge of the temporal variations since the short

circuit occurs until it reaches the permanent short-circuit current. As in practice as quickly as

possible short circuit current by circuit breakers or other devices, knowledge of temporal

variations of the short-circuit current is only necessary to select and size the equipment and

components in some cases.

The parameters involved in the calculation of the short circuit currents are:

I"k: is the rms value of the symmetrical short-circuits current, is the moment when the

short circuit occurs. From this value the following currents are determined.

Is: Maximum current asymmetric short, is the maximum instantaneous value of the

current, which occurs after the short circuit occurs. Also known as peak value or

impulse current. This value may know electrodynamics forces.


Isc: Permanent Short Circuit Current, is the rms value of the symmetrical short-circuit

current, which endures after completion of all transients. Used to determine the

thermal stress on machinery.

Ia: balanced current court, is the rms symmetrical short-circuit current flowing through

a switch on the instant you start separating contacts. Used to determine the

performance characteristics of the switch off apparatus.

This design will be carried out calculations phase short circuits, and these, short circuit away

from the generator. Thus one must take into account that VDE 0102 values permanent short

circuit current (Icc) and cutting the symmetrical current (Ia) coincide with the current value of

the symmetric initial short circuit current (I"k).

4.4.1. Simply Single Line Scheme

The following diagram shows only those different voltage levels, and the status of power

transformers and substation different outputs, in order to perform the calculation of short

circuit currents:

CIT

TT220 kV/25 kV40 MVAUcc=13.8%

TSS

OHE

FEEDER TOUP LINE

FEEDER TODN LINE

FEEDER TOUP LINE

FEEDER TODN LINE

Figure 7. Simply Single Line Scheme.

4.4.2. Equivalent Single Line Scheme

To obtain the equivalent circuit simply replace the transformer by its respective impedance.

The short circuit in the feeder cables will have its maximum value just outside of the

substation, as the absence lead length the short circuit effect is not reduced by the line


impedance. The impedances for conductors and switchgear are negligible and will not be

included in the schemes or calculations.

The equivalent circuit is reflected in the figure below. The figure also marked the possible

points where it can happens different electrical short circuits.

Figure 8. Equivalent circuit.

4.4.3. Impedance Calculations

To perform the calculation method impedances adapted per unit it has to be fixed, first,

arbitrary baseline values. These values determined for each element in intensity per unit.

Values are taken as basis:

SB = 20 MVA

UB = 220 kV

The table shows the values per unit based on an equal basis for all power system

substations.

UB (kV) 220 25

SB (MVA) 20 20

IB (A) 90,9 800

Table 20. Short circuit current per unit based calculation

Observations of the table:

SB = Apparent power kVA basis for the entire system, arbitrary value.


UB = Voltage basis for each kV voltage level is obtained by multiplying the

transformation ratio between two voltage levels.

IB = current per unit A for each voltage level is obtained from the equation:

U

SI

1000

Values in percent transformers having its reference voltage circuit (Ucc).

The short-circuit impedance (ZCC) approximately matches the value shorted reagent (Xcc), so

the error made by omitting the resistance is minimal and does not affect the final results ZCC

Xcc

With the results of the baseline values for each voltage level it is possible to calculate the

impedance by referring to the power unit base. The generic equation for this calculation is:

N

Bcc

S

SZpuZ

100)(

where:

Zcc impedance circuit is in percent.

SB is the power base.

Sn is the rated power of the electrical machine.

The equivalent impedance of the network is obtained as follows: cc

Bnet

S

SZ

where:

SB is the power base.

SCC is the short-circuit power of the network (given by electrical company).

The results are shown in the following table:

Component Characteristics Impedance per unit

referred to SB = 20 MVA

NET Scc = 8800 MVA ZN = 0,0023 pu

RT Sn = 40 MVA

Zcc = 13.8% ZRT = 0,069 pu

Table 21. Impedance per unit calculation


4.4.4. Calculation of the continuous current of short circuit (Isc)

As mentioned above permanent short circuit current (Icc) is equal to the symmetrical initial

current (I"k) and cutting the symmetrical current (Ia). akcc III"

The calculation uses the equation of the Laws Ohm using values per unit: eq

ccz

ui

Where u = 1 when calculating per unit, and zeq the calculated value in the table above for

each point.

Then the resulting values are multiplied by the base value of current, as the voltage level,

obtaining the absolute value of the constant intensity at each point shorting: Bcccc IiI

Short-

circuit

Point

Equivalent

Impedance

[pu]

Short-circuit

current [pu] Base current [A]

Permanent

short-circuit

current [A]

A ZeqA = 0,0023 iccA = 434,78 IB = 90,9 IccA = 39521,74

B ZeqB = 0,069 iccB = 14,49 IB = 800 IccB = 11592

Table 22. Short circuit continuous current calculation

4.4.5. Calculation of the Maximum Current Asymmetric Short-Circuit (Is)

Also called surge current is the maximum value and its value is given by the equation:

ccS IxI 2

Where x is a factor which depends on the relationship between the effective resistance and

the reactance of the circuit impedance. As the resistive value is unknown, take x = 1.8 which

is an accepted value for these cases.

Thus, following the above equation using a value x = 1.8, the impulse current in each short-

circuit point will be the value shown in the following table:


Short-circuit

point

Permanent SC

current (kA)

Maximum Current

Asymmetric SC

(kA)

A IscA = 39.52 IsA = 100.60

B IscB = 11.59 IsB = 29.50

Table 23. Maximum Short-Circuit Asymmetric Current calculation

4.4.6. Rupture capacity and connection

For the election of the switches are fundamental two variables:

Breaking capacity (or power off). Is defined by cutting symmetrical current (Ia). It is

expressed in MVA

anr IUS

Connection capacity (or power connection). Is defined by the maximum asymmetric

short circuit current (IS). It is expressed in MVA

snc IUS

Electric

Point

Cutting

Symmetrical

Current (kA)

Breaking Capacity

(MVA)

Surge Current

(kA)

Connection

Capacity

(MVA)

A IaA = 39.52 SrA = 8694.4 IsA = 100.60 ScA = 22132

B IaB = 11.59 SrB = 289.75 IsB = 29.5 ScB = 737.5

Table 24. Breaking and connection capacity calculation

4.5. Conductor sizing

4.5.1. Type of Conductor

Medium Voltage Cables are manufactured with XLPE insulation. It is very remarkable

features cables, both losses in the dielectric, thermal and electrical resistivity and dielectric

strength.


Being able to work at a service temperature of 90C, these cables have the possibility of

transmitting more power than any current wire section. In addition, its smaller size makes it

more manageable cable, easier to install, lighter and easier to transport.

Type Single pole

Simple Nominal Voltage 26 kV

Nominal voltage

between phases 45 kV

Maximum voltage

between phases 52 kV

Voltage pulses 250 kV

Maximum permanent

temperature allowable in

the conductor

90C

Screen Copper

Isolation Polyethylene (XLPE)

Envelope Polyvinil Chloride (PVC)

Table 25. Conductor characteristics

4.5.2. Size of Conductor

The feeders will be installed into canalization from the TSS to the viaduct. On the viaduct

they will be installed on the parapet, supported by brackets. In case of the feeders of Depots,

they will be into canalization from the TSS to the depot FP and from the FP to OHE.

Therefore, the lower admissible current will occur when the cables are laid down buried into

canalization. According to suppliers information, the admissible nominal current for an

underground copper cable 1x240 mm2 is 501 A (see annex 1), when it is buried at 1.2 m

depth, with ground temperature of 25C and a ground thermal resistivity of 1 Km/W.

Considering that in the worst case, the groud temperature will reach the 40C it will be

needed to consider a deration factor of 0.88. Therefore, the maximum nominal current of

1x240 mm2 copper cable will be 440 A.

4.5.2.1. Permanent current

In case of main tracks, maximum average current will be 439.58 A per feeder, so 219.79 A

per each 240 mm2 cable in permanent operation. Therefore this 240 mm2 cable is valid with

a safety factor of 2.


In case of Depots, maximum nominal current will be 240 A, so one copper cable of 240 mm2

can withstand this current with a safety factor of 1.8.

4.5.2.2. Short time operation current

Regarding short time operation currents caused by overloading of the transformer, the

capacity of one conductor is given by expression:

kBZKB fII (annex 2, chapter 18.6.5, expression 18.122)

Where:

- IKB is the admissible current for short time operation

- Iz is the admissible current for permanent operation

- fkB is overloading factor, given by

b

b

t

t

Z

n

KB

e

eI

I

f

1

1

2

(annex 2, chapter 18.6.5, expression 18.126)

Where:

- In is the initial current before the overload (nominal current)

- tb is the duration of the overload

- is time constant of the cable (1/5 of the time taken from the curve to almost reach

the permissible final temperature). It is given by the expression:

2

ZI

qB (annex 2, chapter 18.6.2, expression 18.117)

Where:

- q is the cross section of the conductor

- B is a constant related with the conductor properties, environment temperature and

the maximum temperature admissible for the cable permanent operation. It is given

by the expression:

201 20

200

c

c cB (annex 2, chapter 18.6.2, expression 18.118)


Where:

- c is the final temperature in the cable by overload current

- 0 is the initial temperature in the cable before the overload

- 20 is the conductivity of the conductor. For copper 56106 1/m

- c is the specific heat of the material. For copper 3.45106 J/Km3

- 20 is the heat transferring factor. For copper 0.00393 K-1

Therefore, the admissible currents for100% and for 50% of overload in the cable will be:

100% overload 50% overload Source of data

c (C) 90 90 Admissible temperature for un XLPE cable

0 (C) 50 50 Initial temperature in the cable before the overload

20 (1/m) 5,60E+07 5,60E+07 From Annex2 table 18.37 20 (1/K) 0,00393 0,00393 From Annex2 table 18.37 c (J/Km3) 3,45E+06 3,45E+06 From Annex2 table 18.37

q (mm2) 240 240 Cross section of the cable

Iz (A) 440 440 Chapter 4.5.2 of this document

In (A) 219.8 219.8 Nominal current in each cable of feeder (Half of RMS value 439.58A, obtained from Traction simulation study)

tb (s) 300 900 Duration of overload: 5 minutes (300s) and 15 min (900s) for 100% and 50% of overload.

B (A2s/m4) 6,06E+15 6,06E+15 Calculated with previous data

1803,18 1803,18 Calculated with previous data fkB 2.268 1.469 Calculated with previous data

IkB (A) 998.12 646.58 Calculated with previous data

Table 26. Short time operation capacity calculation for 240 sqmm copper cable

Therefore, one 240 mm2 cable is able to withstand 998.12 A for 5 minutes and 646.58

during 15 minutes.

According to calculated in chapter 4.2 of this document, the feeder cable (2 cables of 240

mm2) must be dimensioned for withstand 888 A during 15 minutes and 1184 A for 5

minutes, so each cable of 240 mm2 should be able of withstand 444 A during 15 minutes

and 592 A for 5 minutes.

Therefore, 240 mm2 cables are able to withstand the overload currents with safety factors of

1.45 and 1.68.


4.5.2.3. Short circuit current

Regarding of the maximum short circuit current supported by the cable, it can be obtained as

it is shown in the following figure.

As it can be seen in this figure, short circuit current considering duration of fault of 3 s is 19

kA, higher to short circuit current calculated in chapter 4.4.4.

Therefore, copper conductor of 240 mm2 selected is valid for this application.


Section o

f con

ducto

r (m

m2)

Curr

ent

(kA

)

Duration (s)

Figure 9. Short circuit capacity of 240 sqmm copper cable


5. Return Cables

5.1. Return cables

In front of substations, rails will be connected to substation by means of 3.3 kV cables. Their

aim is to carry the return traction current from rails to substation, so they must withstand the

same current than 25 kV feeders. Therefore they will be made up of the same number of

cables and cross section, as the 25 KV feeders.

5.2. Return conductor

One all aluminium conductor with a nominal cross section of 233 sq.mm and a copper

equivalent of 140 sq.mm will be used as Return Conductor. Dimensioning of this return

conductor has been developed according to the worst criterion of following ones:

Maximum admissible current for conductors will be taken into account in order to

select the cable according to the maximum calculated current in normal conditions.

Voltage drop will be calculated in order to maintain minimum voltage above the

minimum voltage required for operation, which is 19 kV, according to EN.

Conductors must withstand mechanical and thermal loads during a short circuit.

5.2.1. Rated current calculation (In)

In the Return current system foreseen, the return conductor must carry the same current as

catenary. Therefore it must be dimensioned for carrying the same current calculated in the

chapter 4.1.1., (439.58 A).

The maximum admissible current for one all aluminium conductor (AAC) with a nominal

cross section of 233 sq.mm is 584 A in the following conditions (annex 3):

Environmental temperature: 40C

Solar radiation 900 W/m2.

Wind: 0.6 m/s

Maximum conductor temperature: 80C

Frequency: 50Hz

Applying a deration factor of 0.9 to take into account the solar radiation and other deration

factor of 0.89 to take into account that the worst environmental temperature will be 50C, the

maximum admissible current will be 467.78 A, so the conductor selected is valid for the

nominal current.


In stations, return conductor will be made by means a 233 sq.mm stranded aluminium

conductor, with insulated sleeve. It will be laid under platforms.

5.2.2. Voltage drop

Voltage drop calculated in Traction Simulation Study for Line 7 has already into account the

characteristics of return conductors, so it is not needed any additional calculation.

5.2.3. Short circuit criteria

Regarding of the maximum short circuit current supported by the Return conductor, it can be

obtained by means of following expression:

Where:

I: Short circuit current (A)

t: Short circuit duration (s)

K: parameter which depends of kind of conductor (Cu or Al) and of its isolation. In

present case with aluminium conductors, K = 94 will be assumed (jump of

temperature from steady temperature to short circuit temperature minimum), so worst

scenario has been assumed.

S: cross section of the conductor (mm2)

Therefore, the minimum section required to withstand the short circuit current calculated in

chapter 4.4.4 will be:

I (A) 11600 Calculated in chapter 4.4.4 of this document

t (s) 0.25 Short circuit duration (estimated as

conservative value)

K 94 Value for aluminium conductor

S (mm2) 61.7 Calculated with previous data

Table 27. Return conductor sizing under short circuit current criteria

Therefore, aluminium conductor of 233 mm2 selected is valid as return conductor.

6. Induced Voltage Calculation

According to IEC 60287-1-3:2002, induced voltage per unit length in a conductor can be

determined by the following expression:


km

VIMfE 3102

Where:

f: is the frequency of the nominal voltage waveform

I: is the maximum permanent current main conductor

M: is the mutual inductance between two conductors arranged in parallel given by the

expression:

km

mH

D

DM

p

m2log46,0

where:

Dm: is the distance between the two conductors 2

'dDDm

Dp: is the equivalent diameter of conductor induced S

D p4

For cable 26/45kV XLPE, Cu 240 Sqmm the characteristics are:

d = 18.3 mm

d' = 20.1 mm

D = 38.5 mm

Screen = 16 mm2

Figure 10. Cross section of XLPE insulated cable

The maximum drop voltage in case of the end of the cable being earthed is given by the

expression:


LEV

where:

E: induced voltage per unit length in a conductor

L: Length of conductor

According to this length in each case, the drop of voltage will be obtained per each feeder:

Mukundpur Dhaula

Kuan INA

Vinod

Nagar Maujpur

Rajouri

Garden

Kashemere

Gate

f (Hz) 50 50 50 50 50 50 50

I (A) 219.79 219.79 219.79 219.79 219.79 219.79 219.79

Dm (mm) 8 8 8 8 8 8 8

Dp (mm) 4.514 4.514 4.514 4.514 4.514 4.514 4.514

M (mH/km) 0.252 0.252 0.252 0.252 0.252 0.252 0.252

E(V/km) 17.46 17.46 17.46 17.46 17.46 17.46 17.46

L (km) 1.5 1.5* 1.2 0.7 2.1 1.1* 2.75*

V (V) 26.19 26.19 20.94 12.22 36.65 45.41 48.01

(*) Length obtained earthing the sheath cable in it center point

Table 28. Induced Voltage Calculation

Therefore, in all cases the voltage in the sheath can be lower than touch voltage by earthing

the cables in one end or in their center point and no sheath voltage limiters will be required.

7. Circuit Breakers rating

Circuit breakers are foreseen in the outgoing feeders in traction substations (TSSs), and in

depots Feeding posts, installed in the incoming feeder from TSS and in the incoming feeder

from main tracks.

In any case, circuit breakers must be able to actuate in short circuit conditions. Therefore, for

the election of the circuit breakers are fundamental two variables:

Breaking capacity (or power off). Is defined by cutting symmetrical current (Ia). It is

expressed in MVA

Connection capacity (or power connection). Is defined by the maximum asymmetric

short circuit current (IS). It is expressed in MVA


These variables have been calculated in the chapter 4.4.6 of these documents, and,

regarding 25 kV circuit breakers they are:

Cutting Symmetrical Current: Ia = 11.59 kA

Breaking Capacity: Sr = 289.75 MVA

Surge Current: Is = 29.5 kA

Connection Capacity: Sc = 737.5 MVA

Regarding voltage, they must able to withstand nominal values foreseen in the traction

system:

Rated voltage: 25 kV

Maximum service voltage (permanent): 27.5 kV

Therefore, the characteristics required for the circuit breakers foreseen in Mukundpur and

Vinod Nagar Depot Feeding posts, as well in feeders of Rajouri Garden FP, Dhaula Kuan FP

and Welcome FP will be:

Rated voltage kV 25

Maximum service voltage (permanent) kV 27.5

Service frequency Hz 50

Number of phases 1

Erection Outdoor

Rated current A 2000

3 sec. Short time current kA 25

Symmetrical breaking capacity kA 25

Rated peak withstand current kA 40

Table 29. Circuit Breakers characteristics

8. Interrupters rating

Interrupters foreseen in the OHE have to be able to operate under load conditions.

According to calculations shown in the chapter 4.1 the maximum nominal current through

each feeder is 439.58 A.


Catenaries for up and down tracks are paralleled in SSPs along the track. Therefore, the

interrupters will be dimensioned for the total current of the two tracks:

In= 439.58 + 384.58 = 824.16 A.


system:



Therefore, the characteristics required for the interrupters foreseen in the switching posts of

Line 7 will be:

Rated voltage kV 25

Maximum service voltage (permanent) kV 27.5

Service frequency Hz 50

Number of phases 1

Erection Outdoor

Rated current A 2000

Table 30. Interrupters characteristics

9. Current Transformers rating

Current transformers will be used in depots Feeding post for current measuring and

protection. Therefore, they must be rated for the nominal current foreseen in depots which is

240 A according to calculations included in chapter 4.1.2.

In addition, current transformers will be used in feeders in:

Rajouri Garden FP

Dhaula Kuan FP

Welcome FP


system:




Therefore, the characteristics required for the current transformers in OHE part will be:

Voltage / earth insulation kV 27.5

Frequency Hz 50

Erection Outdoor

Insulation withstand voltage (permanent) kV 36

Secondary Core

Core 1 600/1, 5P10, 20VA

Protection class

Core 2 600/1, 5P10, 15VA

Protection class

Withstand Over-current (1s /peaks) kA 20 / 40

Table 31. Current transformers characteristics


ANNEX 1. TECHNICAL DATA OF 26/45 KV XLPE

INSULATED COPPER CABLE USED FOR CALCULATION.

media tensin anexo b

DATOS TCNICOS DEL CABLE VOLTALENE H 26/45 kV (conductor de cobre)RHZ1

26/45 kV1x35/161x50/161x70/161x95/161x120/161x150/161x185/161x240/161x300/161x400/161x500/161x630/161x800/161x1000/16

1712022482973383814315015656447318249211007

17420725831436141147255864074386098411321269

0,5240,3870,2680,1930,1530,1240,09910,07540,06010,0470,03660,02830,02210,0176

0,1590,1520,1440,1360,1320,1250,1210,1150,1120,1060,1020,0980,0950,090

0,1350,1440,1610,1750,1860,2090,2260,2490,2750,3410,3750,4110,4600,546

1 x seccinconductor

(Cu)/seccinpantalla (Cu)

(mm2)

Cdigo conductor(mm)

aislamiento(mm)

pantalla (mm) cable (mm) Peso (kg/km)

Radio decurvaturaesttico

(posicin final)(mm)

Radio decurvaturadinmico

(durante tendido)(mm)

26/45 kV1x35/161x50/161x70/161x95/161x120/161x150/161x185/161x240/161x300/161x400/161x500/161x630/161x800/161x1000/16

2011786120117862201178633701133520052424209923402001378720084553200017422011786437011342201065692011786520117866

78

9,711,412,614,115,918,320,523,126,329,634,138,7

24,925,827,629,230,530,932,735,137,838,942

45,449,953,5

26,929,231

32,633,934,336,138,541,242,345,448,853,356,9

34,435,437,238,740

40,442,244,647,348,451,554,960

63,6

132014601720201022902520291035004180491060207410949011550

5505665956196406466757147577748248789601018

6887087447748008088448929469681030109812001272

*Condiciones de instalacin: una terna de cables directamente enterrada o bajo tubo a 1,2 m de profundidad, temperatura de terreno 25 C y resisitividad trmica 1 Km/W.**Condiciones de instalacin: una terna de cables al aire (a la sombra) a 40 C.

NOTA: valores obtenidos para una terna de cables al tresbolillo y en contacto. Para el clculo de la reactancia inductiva con los conductores en cualquier disposicin aplicar la frmula(A) de la pgina 214.

IMPORTANTE: Para los valores concretos de intensidades mximas segn los conexionados de pantalla se ruega contactar con Prysmian.

CARACTERSTICAS DIMENSIONALES (Valores aproximados)

(Valores aproximados)

1 x seccin conductor(Cu)/seccin pantalla

(Cu) (mm2)

Intensidad mximaadmisible enterrado*

(A)

Intensidad mximaadmisible

al aire** (A)

Resistencia delconductor a 20 C

(/km)

Reactancia inductiva(/km)

Capacidad(F/km)

CARACTERSTICAS ELCTRICAS

Tensin nominal simple, Uo (kV)Tensin nominal entre fases, U (kV)Tensin mxima entre fases, Um (kV)Tensin a impulsos, Up (kV)Temperatura mxima admisible en el conductor en servicio permanente (C)Temperatura mxima admisible en el conductor en rgimen de cortocircuito (C)

26455225090250

26/45 kV

201

administrRectngulo


ANNEX 2. GUIDE FOR CALCULATION OF CABLE

CAPACITY UNDER SHORT TIME OPERATION CURRENTS.


ANNEX 3. TECHNICAL DATA OF ALUMINIUM CABLES

USED FOR CALCULATION.

(1) Para conductor expuesto a una radiacin solar de 900 W/m, considerando una emisividad de 0,6, al nivel del mar y viento de 0,6 m/seg, temperatura ambiente de 40 C, temperatura mxima admisible de 80C y una frecuencia de 50 Hz.

31

Seccin nominal

Formacin Dimetro

exterior

aprox.

Masa

aprox.

Carga de rotu-ra calculada

Resistencia

elctrica mxima

a 20oC y

c. c.

Intensidad

de corriente

admisible (1)

mm2 N x mm mm kg/km kg ohm/km A

10 7 x 1,35 4,1 27 195 2,7842 78

16 7 x 1,70 5,1 43 302 1,7558 104

25 7 x 2,15 6,5 70 457 1,0977 139

35 7 x 2,52 7,6 95 594 0,7990 171

50 7 x 3,02 9,1 135 827 0,5563 215

70 19 x 2,15 10,8 190 1242 0,4025 265

95 19 x 2,52 12,6 260 1611 0,2930 324

120 19 x 2,85 14,3 335 2061 0,2291 380

150 37 x 2,25 15,8 405 2648 0,1877 431

185 37 x 2,52 17,7 510 3137 0,1496 498

240 37 x 2,85 20,0 650 4013 0,1170 584

300 61 x 2,52 22,7 840 5172 0,0907 687

400 61 x 2,85 25,7 1075 6615 0,0709 804

500 61 x 3,23 29,1 1381 8247 0,0552 942

625 91 x 2,96 32,6 1732 10645 0,0439 1087

800 91 x 3,35 36,9 2218 13234 0,0343 1266

1000 91 x 3,74 41,1 2764 15995 0,0275 1445

1265 91 x 4,21 46,3 3503 20268 0,0217 1657

Caractersticas Tcnicas

Bobinas de

madera

Acondicionamientos:

Cables segn norma IRAM 63003

Prysal Aluminio

administrRectngulo


ANNEX 4. ROLLING STOCK DATA USED FOR

CALCULATION

Documents

25 kV Equipment Sizing Calculationv5_ (1).pdf