Reis - Roger White DC Presentation

DC Rail ilway way Electr Electrif ific ica ati tion on Sys ystt em De Desi sign gn Railway Electrification Infrastructure School •

07 June 09

System June 2013 Dr Roger D White [email protected]

1

Lecture Contents

1.

World Syste System m Voltage Voltages s

2.

HV Supply Arrangement

3.

Distribution of DC Traction Supply

4.

D.C. Feeding Arrangement

5.

Trackside DC Substation Design

6.

Substation Electrical Performance Specification

7.

Traction Return Current

8.

Earthing

9.

Regeneration

10.

DC Magnetic Fields

11.

Cable Specification

12.

Induced Voltage

13.

Lightning Protection

14.

Disturbance effects

Lecture Contents

1.

World Syste System m Voltage Voltages s

2.


3.


4.


5.


6.


7.


8.

Earthing

9.

Regeneration

10.

DC Magnetic Fields

11.

Cable Specification

12.

Induced Voltage

13.


14.

Disturbance effects

World System Voltages



DC System Voltage  160, 180, 500, 525, 550, 600,630, 650, 750, 800, 825, 850, 860, 900, 1000,1200, 1350, 1500, 2400, 3000, 3500, 6000DC



11,000 16 2/3 Hz, 15,000 16 2/3



15,000 Variable Frequency up to 50 Hz  Zosen to Marienfede [Trial 1901-1904]



Three Phase  725 V [Gornergratbahn] , 1125[Jungfraubahn],  3600 16 2/3 Hz three-phase t hree-phase [ 1912-1976]



Single Phase AC System Voltage:  6.25/ 50, 6.3/25, 11/ 25, 12.5/60, 20/50 , 20/60 , 25/50, 25/ 60, 50.50 kv/Hz

AC and DC Electrification

i r e W h r t E a

400kV GRID

Grid Site

Feeder Station

Overhead Contact System

Train

R Y

Busbar + 25kV

B

25 kV 50 Hz 2 Track Traction Return System

NORTH

SGT1 Y-B

i r e W h t r E a

3kV d.c. C D o t C A

C A o t C D

66/132kV GRID

Grid Site

Sub Station

1000V 3 phase

R Y B

Overhead Contact System

Train

0.75/1.5/3 kV d.c. C D o t C A

2 Track Traction Return System

NORTH

C A o t C D

UK DC Networks







NR 750V 

DC electrified track 4,285 single track kms;



DC sub-stations (430);

LU Network 

+420 V DC –210 V DC, giving a supply voltage of 630 V DC



408 km (253 miles) [11 lines electrified in the 1890s

550 V DC overhead; 





750 V DC, Overhead 

Croydon, (39 Stations ; route 28km)



Manchester, (50 Stations; route 37km)



Midland Metro: ( 23 Stations; 20km)



Sheffield: (48 Stations: route 29km)



Nottingham Super Tram: (23 Stations; route14km)

750V Docklands Light Rail third rail 



Blackpool Tram (61 Stations route 18km)

45 stations route 40km

1,500 V DC, Overhead Tyne & Wear Metro 

60 Stations route 77.7km

LRT Passenger Journeys Light Rail and Tram Statistics DoT 2011/2012


1.


2.


3.


4.


5.


6.


7.


8.

Earthing

9.

Regeneration

10.

DC Magnetic Fields

11.

Cable Specification

12.

Induced Voltage

13.


14.

Disturbance effects

High Voltage Supply Feeding Arrangement


1.


2.


3.

Distrib ution of DC Tra Traction ction Supply

4.


5.


6.


7.


8.

Earthing

9.

Regeneration

10.

DC Magnetic Fields

11.

Cable Specification

12.

Induced Voltage

13.


14.

Disturbance effects

DC Railway Contact Systems 

600V/650V/750V suburban third rail



630V fourth rail system LUL



Overhead Line 

750V LRT/Tram LRT



1500V dc Metro system



3000Vdc OHL suburban and intercity;

Factors Influencing DC Substation Spacing



Maximum permissible system voltage drop



Traction loading/performance/



Train auxiliaries



Third rail conductor cross section



Electrification protection settings

Most Economic Distance between Substation BS EN 501288





630V d.c. Electrification System is 

2-3km [LU]



+420V rail

660-750 V d.c. Electrification System 



3--6km

1500V dc Electrification System 



-210 V rail.

5-13km

3000V dc Electrification System 

8-20km

Pictures 1500V Sydney Australia

DC. Feeding Arrangement 1.


2.


3.


4.


5.


6.


7.


8.

Earthing

9.

Regeneration

10.

DC Magnetic Fields

11.

Cable Specification

12.

Induced Voltage

13.


14.

Disturbance effects

General view of a completed Conductor Beam installation (From Furrer and Frey literature)

DC. Feeding Arrangement 1.


2.


3.


4.


5.


6.


7.


8.

Earthing

9.

Regeneration

10.

DC Magnetic Fields

11.

Cable Specification

12.

Induced Voltage

13.


14.

Disturbance effects

General view of a completed Conductor Beam installation (From Furrer and Frey literature)

DC Traction Feeding Arrangement

33/11kV Supply

33/11kV Supply Power Transformer Circuit Breaker Normally Closed Rectifier Unit

Feeder Station

Isolator Normally Open Insulated Overlap or Sectioning Gap

I/4

I/4

I/4

I/4

I/4

I/4

Rail current I/8 if both rails available Rail current I/4 if one rail is available per track

Feeding Arrangement

Normal Feeding Arrangement 

Normal feeding 

track sectionalisation areas



Tee feeding arrangement



Single end feeding arrangement

Degraded Mode 

Loss of supply of transformer rectifier units



Bypass feeding arrangement


1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

World System Voltages HV Supply Arrangement Distribution of DC Traction Supply D.C. Feeding Arrangement Tracks ide DC Substatio n Desig n Substation Electrical Performance Specification Traction Return Current Earthing Regeneration DC Magnetic Fields Cable Specification Induced Voltage Lightning Protection Disturbance effects

Supply and converter design arrangements





Transformer winding design factors: 

short circuit reactance,



commutating reactance

Transformer reactance determine: 

d.c. short circuit fault current,



operating d.c. voltage regulation,



operating load loss [winding resistance]



transformer efficiency,



Transformer & converter power factor



harmonics supply side

6 Pulse converter

3 Phase Fully Controlled Bridge

50Hz 3 Phase Line to Line

Vdc 6 Pulse

750V 1500V dc 6 Pulse Rectifier

20 mS

12 Pulse Series Bridge Converter

Transformer Secondary Windings Phase Displaced

12 Pulse Converter

Switch Gear and Busbars

Overhead Line or Third Rail

50Hz 3 Phase Line to Line Vdc 12 Pulse

Return Running Rails 750V 1500 V dc

12 Pulse Rectifier

20 mS

12 Pulse Parallel Bridge Converter

Transformer Secondary Windings Phase Displaced

12 Pulse Converter

Switch Gear and Busbars

Overhead Line or Third Rail

50Hz 3 Phase Line to Line Vdc 12 Pulse

Parallel Interface Transformer

Return Running Rails 750V 1500 V dc

12 Pulse Rectifier

20 mS

Rectifier Protection



Short Circui t Protectio n 





short circuit, overloading: thermal relay and over current time relay.

Internal Short Circuit s 

failure of one of the rectifier arms.



two-phase transformer fault current



Diodes fully rated

Over Voltages 

Switching, interruption, lightning.



attenuated with a resistor capacitor network



commutation ‘hole storage’

LAR Rectifier Hong Kong

Rectifier Mechanical Construction







Diodes 

aluminum extruded heat sinks,



connected in parallel in a bridge



hermetically sealed



diode fuses and micro switches,

Heat sinks natural air cooling. AC and DC busbars are arranged at top or bottom of the cubicle.

Substation Electrical Performance

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

World System Voltages HV Supply Arrangement Distribution of DC Traction Supply D.C. Feeding Arrangement Trackside DC Substation Design Substation Electric al Performance Traction Return Current Earthing Regeneration DC Magnetic Fields Cable Specification Induced Voltage Lightning Protection Disturbance effects

Substation Electrical Performance

1.

Substation rating

2.

DC Traction supply voltage

3.

Regulation of DC traction voltage

4.

DC short circuit fault current

5.

Power factor of rectifier unit

6.

AC and DC harmonics

1

Typical specification 750V sub station system



Rated capacity 2400kW



Rated D.C. traction voltage 600VDC



Rated D.C. traction current 4000A



Short circuit protection 40 kA 0.25 sec



Transformer 22kV/415V



Rated Capacity 2½ MVA



Short circuit protection 40 kA 0.25 Sec

Fault Profile

2

DC Traction supply voltage European regulation EN 50163

Table 1 Definition of operating d.c. System Voltages

lowest non permanent voltage duration 10min, lowest permanent voltage duration indefinitely, nominal voltage designed system value, highest permanent voltage duration indefinitely highest non permanent voltage duration 5 min. Ref[1]

EN50163[Table 1,]

600*

750

1500

3000

400 600 720 770+

500 750 900 950^

1000 1500 1800 1950

2000 3000 3600 3900

3

Voltage Regulation with Track Sectioning Hut

33/11kV Supply


Feeder Station


I/4

I/4

I/4

I/4

I/4

I/4

Rail current I/8 if both rails available Rail current I/4 if one rail is available per track

4

Short Circuit with track Parallel Hut

33/11kV Supply


Feeder Station


Ia

Ia

I b /2 Ia +I b

Ia +I b Ia +I b

I b /2 I b /4 I b /4 I b /4 I b /4

Rail current Ib /4 if both rails available

I b /2

DC Short Circuit Current Waveform

LUL Double DC earth fault >100kA

Double Pole Earth Fault

Rail leakage

Bleed Resistors

Double Earth Fault +420V

250 Ohm

125 Ohm

Rail Leakage

Rail Leakage

Rail Leakage

-210V

5



Power Factor of Traction Rectifier Unit

Power Factor AC System Characteristic 



3 phase

Power factor dependencies: 

Transformer design



Converter design/arrangement



DC Traction load



DC Auxiliary Load



Harmonics in the AC Current

6

Production of AC and DC Characteristic Harmonics

Pulse Number DC Harmonics

AC Harmonics

p

np

np ± 1

6

0,6,12,18,24

1,5,7,11,13,17,19,23, 25

12

0,

1,

12,

24

11,13,

23,25

Harmonics in DC Electrification Systems





Harmonics are responsible for: 

Overheating capacitors



Overheating generators & induction motors



Instability in converter control systems



Interference into control systems



Noise on telephone lines



Interference into signalling systems

Harmonics can be reduced by: 

Increasing converter pulse number



Installation of filters

System

Planning Levels [IEC 61000-3-6]

Compatibility Levels

400V

5%

8% [IEC 61000-2-2]

6.6, 11, 22 kV

4%

8% [IEC 61000-2-12]

>20kV and <145kV

3%

5%

275 and 400kV

3%

3.5% [UK]

[UK]

Rectifier Performance Characteristics


1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

World System Voltages HV Supply Arrangement Distribution of DC Traction Supply D.C. Feeding Arrangement Trackside DC Substation Design Substation Electrical Performance Specification Tracti on Return Current Earthing Regeneration DC Magnetic Fields Cable Specification Induced Voltage Lightning Protection Disturbance effects




Fourth Rail Systems:  London Underground UK



Diode/Floating Earthed Railway  Hong Kong MTRC,  DLR  Manchester Metro



Floating Negative Earth  Network Rail Southern, Japan, Australia  Singapore MRT, Hong Kong LRT,  Lantau and Airport Hong Kong  Croydon Tram; Nottingam Tram  Sheffield Super Tram,  Edinburgh tram; Dubai Metro;

Typical Earthing Diode Earthed Railway

Traction Current

Catenary

SubstationRectifier DC System Voltage

Traction Return Current Main Earth bar

Vrail

Vrail

Vrail

Diode Earth

Vrail

Distance

Traction Current

Substation Rectifier

Catenary

DC System Voltage

Traction Return Current Main Earth bar

Vrail

Vrail

Vrail

Vrail

Distance

Testing rail insulation

Rail and Utility Potentials

Traction Current

Catenary

Vdc

Rail Return Rail Resistance

Leakage Resistance Utility Corrosion Remote Ground

Potential of Rails Scale in 10(s) Volts

Potential of Utility with Interference Scale in 100(s) mV

Traction Earthing

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

World System Voltages HV Supply Arrangement Distribution of DC Traction Supply D.C. Feeding Arrangement Trackside DC Substation Design Substation Electrical Performance Specification Traction Return Current Tractio n Earthin g Regeneration DC Magnetic Fields Cable Specification Induced Voltage Lightning Protection Disturbance effects

Traction Earthing and Bonding



Provide a safe return path for traction load;



Ensure good return path for fault current;



Maintain the potential of all accessible metalwork; 

120V Mainline



60V depots



Traction or fault current in metallic services



Prevent arcing



Protective Earthing: Equipment



Functional Earth: Equipment



Suppression of Electrical Noise: EMC



Lightning protection,



Corrosion control

Earthing Standards European and National



UK and European 



 







LUL Standards 



 





European Standard EN 50122 -1 electrical safety and earthing European Standard EN 50122- 2 provision against stray currents BS 7430 Code of Practice for Earthing BS 7671 17th Edition of the IEE Wiring Regulations G59/1 Electricity Association Engineering Recommendation G5/4 Electricity Council Regulations 1-106 Earthing and Bonding of LU Electrical Networks MR-S-PO-0009-Part 1Earthing Code of Practice MR-S-PO-0008 Earthing management E7720 A3 Engineering Standard 25kV 50Hz immunisation SSL-SE-0858-A1 Earthing Practice 1985- Signal Engineering.

Network Rail 

NR/SP/ELPE/21032 Network Rail Earthing Systems

Typical DC Electrification Earthing Arrangement

Earth Wire

Telecoms PSU

Telecoms. Cable

Distribution Network Operator Supply

DC Voltage

Track circuit

NGC Substation

SignallingPSU

Track Structures

Local RECS Station Apparatus Tunnel Structure

Rebars Copper Earth Mat

Station Metallic Structures

© R D White 2007

Depot Bonding Arrangement AC Sub Station

M&E earth

M&E Earth

Fault return path

Traction Bond

M&E CPCearth rated for 1500V fault current 300sq mmCu ( to be determined by Siemens) Traction return bonding 6 times 250sqmm ( to be determined by Siemens) Non Electrified lines

Test Track DC Sub Station Main Earth Bar minimum 400mm2

Infrastructure and Maintenance rails earthed No 1500V

OVPD

SS & Car Wash & Approach Roads 400sqmm cables

Car Wash OCS 1500 V

Main Earth Bar minimum 400mm2

HMS & LMS 400sqmm cables

Propsed new location of the IRJ

Stabling Shed (SS) 20 Roads Rails Floating OCS1500V

HMS Rails Earthed OCS 1500V

Bogie Drop

LMS Rails Earthed OCS 1500V

Earthed

Floating

C r a n e

Wheel lathe

Main Earth Bar minimum 400mm2

Lift Jacks DPS DPS

Main Earth Bar 2 minimum 400mm

E&M earth Fault

LMS 1500V earth fault to rails: SS 1500 V earth fault rails LMS 1500V earth fault to structure SS 1500 V earth fault structure Car Wash 1500 V earth fault structure

Path

Structure bond/rails/return bonds Return bonds Rails Return Bonds Fault Return Path Fault Return Path

Protection

dc breakers dc breakers dc breakers OVPD& DC Breakers OVPD& DC Breakers

Fau lt

Path

Protection

HMS 1500V earth fault to rails HMS 1500 V earth fault structure

Return Bonds Structure bonds/Rails /return Bonds

dc Breakers dc Breakers

1

Our Ref: DC Depot Bonding.vsd

Revision Record

9 0 / 2 1 / 4 1

Issue: 1

14 Dec 2009

Drawn by: Checked by: Approved by:

R D White D Ellis

Client:

Proposed DC Rail and Structure Bonding of Traction Maintenance Depot Title:

Project:

MMMP

Note 1 SS and HMS are the same civil structure Note 2 Failure of the OCS to the structure where rails are floating, the return path is via the MEB and OVPD is required to close to clear dc breakers. Note 3 Failure of the OCS to the structure where rails are earthed the return path is via the MEB and the DC Bonds to clear dc breakers.

System Earthing

Bonding in Tunnel Structures (Dubai)

Civil Insulation PSD Monito ring o n PSD Isolatio n Test

2.000

1.000

0.500

)

Ω

0.250 M ( e c n a t s i s 0.125 e R

0.063

0.031

0.016 0

10

20

30

40

50

60

70

80

90

100

‘Stray Current Collection’

Traction Current

Catenary

Vdc

Rail Return Rail Resistance

Leakage Resistance

Corrosion Remote Ground

Potential of Rails Scale in 10s Volts

Potential of Utility with Interference Scale in 100s mV

Stray DC Current and Corrosion





Protection Required 

reinforcing bars of railway structures



reinforced concrete track bed



electrical utilities



water and gas pipes

Corrosion 

Discharged of leakage current



Typically 1A corrodes 9.1kg of iron per year

North London Lines AC DC Operation

Regeneration

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

World System Voltages HV Supply Arrangement Distribution of DC Traction Supply D.C. Feeding Arrangement Trackside DC Substation Design Substation Electrical Performance Specification Traction Return Current Earthing Regeneration DC Magnetic Fields Cable Specification Induced Voltage Lightning Protection Disturbance effects

Regenerative Traction Units and Supply Points

Rheostatic brakes on Croydon Trams



Technical Merits of Regenerative Traction Units  Reduction of heat  Reduction of brake dust  Reduction of tunnel maintenance  Elimination of brake resistors.



Technical Merits of Regenerative System  Improved efficiency  reduction in energy costs.



Disadvantages of Regenerative Systems  More capital investment in traction and supply equipment.  More harmonics [medium voltage supply].  Intelligent protection system on the supply and traction.  Increase stray current



dc network losses charged at 15.57% in the southern region;



dc network losses charged at 10.26% for the dc network in Merseyside;

DC Magnetic Fields

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.


Magnetic Electric Fields and Overhead Lines

Magnetic Field Amps/m

Electric Field Volts/m

1500V DC twin track 3000A per track

ELECTRIC FIELD 1500V DC Roger D White WS Atkins Rail

EmagField

Cable Specification

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

World System Voltages HV Supply Arrangement Distribution of DC Traction Supply D.C. Feeding Arrangement Trackside DC Substation Design Substation Electrical Performance Specification Traction Return Current Earthing Regeneration DC Magnetic Fields Cable Specif ication Induced Voltage Lightning Protection Disturbance effects

Cables and Conductors Applications



Systems 33kV & 11kV Distribution and substation feed



D.C, traction return cables;



D.C. feeder cables;



Track bonding;



Lineside cables;



Overhead line conductors;



Tunnels [no smoke zero halogen]

Cable Insulation Specifications



Track Application 

copper and aluminum,



XLPE insulation [cross linked polyethylene]



concentric solid core, stranded cables .







Armour and PVC Coating

Older Cables 

oil impregnated insulated paper tapes.



Outer core protected by steel tape, or galvanized wire armouring.

HV Supply and Distribution 

solid, gas or oil-filled cables.



ratings in excess 33kV



33kV fluid filled and XLPE [substation]



XLPE [cross linked polyethylene]



Armour and PVC Coating

Induced Voltage

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

World System Voltages HV Supply Arrangement Distribution of DC Traction Supply D.C. Feeding Arrangement Trackside DC Substation Design Substation Electrical Performance Specification Traction Return Current Earthing Regeneration DC Magnetic Fields Cable Specification Induced Volt age Lightning Protection Disturbance effects

Electrical System Characteristics

Victim Cable  Position of receptor cables telecoms cables Signalling cables  Parallelism of cables/ DC/HV AC  mutual impedance as a function frequency  screening factors of the earthed conductor Electrical Dependencies  Change of traction load or fault current [ time varying]  DC Ripple [rectifier supply]  Coupling increases with harmonics [j2.π.f.M]  Fast transients [ power supply]  Normal load Current Typically < 4000A  Fault current typically < 100kA  Parallelism with 25kV railways ( 50Hz only)  Traction unit psophometrically weighted current


1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.







Lightning Protection on DC switchboard 

Prevent OHL surges,



Surge protection fitted on each feeder circuit breaker,

Exposed masts on Viaducts 

Lightning protection for Radio Antenna and other masts



Signal Heads

Disturbance effects

1.


2.


3.


4.


5.


6.


7.


8.

Earthing

9.

Regeneration

10.

DC Magnetic Fields

11.

Cable Specification

12.

Induced Voltage

13.


14.

Disturbance effects

Disturbance Effects of DC Electrification Systems

AC LV and HV Systems  AC side harmonics in 3 phase supply  AC voltage distortion  Power factor  Lightning DC and Power System Harmonics  DC Side Harmonics  Overlap effect,  Resonance and system capacitance  Traction line filter resonance  Magnetic and Electric Fields

Inductive and Radiated Effects  





  

High frequency radiated emissions Traction load traction to regeneration. Power arcs on the ramp end of the rails Disturbance changes supply & traction Switching of the d.c. power [di/dt] Longitudinal Transverse voltages Lightning

Return Circuit and DC Stray Current   

Harmonics in the return circuits Conductor overheating Corrosion due to DC stray current

Key System Interfaces







Physical Interfaces (OLE to Civil structures, Signalling, Comms) 

OHL clearances



Power line clearances



Signalling mast clearances



Touch and step potentials ( clearance 2.5m)

Electrical Supply Interfaces (Depot and mainline ) 

Supply feeding



Segregation of feeding



Degraded mode of operation





Earthing Interfaces (Traction Return to Civil Earth, DNO Signalling Earth, Comms earth and Third Party Earth) 

Interconnection of Earths



Rating of the earth connection



Segregation of earths

Magnetic Coupling (OLE to Comms and Signalling) 

Induced voltage



Noise on telephone systems



Disturbances to communication systems

Magnetic Coupling (Power Lines to Comms and Signalling) 

Induced voltage



Noise on telephone systems



Disturbances to communication systems

Stray DC Current (Traction return and civil structures) 

Civil Clearances



Corrosion of railway civil structures



Utilities

Reis - Roger White DC Presentation

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