reis - roger white dc presentation

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DC Railway Electrification System Design Railway Electrification

Infrastructure School • 07 June 09

Dr Roger D White [email protected]

System June 2013

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Lecture Contents

1. World System Voltages 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

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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 [ 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

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AC and DC Electrification

SGT1 Y-B

Earth W

ire400kV GRID

B

YR

+ 25kV

Busbar

AC to

DC

DC to

AC

25 kV 50 Hz 3kV d.c.

TrainOverhead Contact SystemFeeder StationGrid Site

2 TrackTraction Return

System

NORTH

Earth W

ire66/132kV GRID

B

YR

DC to

AC

0.75/1.5/3 kV d.c.

TrainOverhead Contact SystemSub StationGrid Site

2 TrackTraction Return

System

NORTHAC to

DC

1000V 3 phase

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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; Blackpool Tram (61 Stations route 18km)

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 45 stations route 40km

1,500 V DC, Overhead Tyne & Wear Metro 60 Stations route 77.7km

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

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HV Supply Arrangement


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High Voltage Supply Feeding Arrangement

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Distribution of DC Traction Supply


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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;

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Factors Influencing DC Substation Spacing

Maximum permissible system voltage drop

Traction loading/performance/

Train auxiliaries

Third rail conductor cross section

Electrification protection settings

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Most Economic Distance between Substation BS EN 501288

630V d.c. Electrification System is 2-3km [LU] +420V rail -210 V rail.

660-750 V d.c. Electrification System

3--6km 1500V dc Electrification System

5-13km

3000V dc Electrification System 8-20km

Pictures 1500V Sydney Australia

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DC. Feeding Arrangement

1. World System Voltages 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

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

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DC. Feeding Arrangement



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

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DC Traction Feeding Arrangement

I/4

I/4

33/11kV Supply

Feeder Station

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

Power Transformer

Circuit Breaker Normally Closed

Rectifier Unit

Isolator Normally Open

Insulated Overlap or Sectioning Gap

I/4

I/4

33/11kV Supply

I/4 I/4

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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

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Trackside DC Substation Design


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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

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6 Pulse converter

50Hz 3 Phase Line to Line

3 Phase Fully Controlled Bridge

20 mS

750V 1500V

dc

6 Pulse Rectifier

Vdc 6 Pulse

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12 Pulse Series Bridge Converter


12 Pulse Converter

20 mS

750V 1500V dc

12 Pulse Rectifier

Vdc 12 Pulse

Transformer Secondary Windings

Phase Displaced

Overhead Line or Third Rail

Return Running Rails

Switch Gear and Busbars

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12 Pulse Parallel Bridge Converter


12 Pulse Converter

20 mS

750V 1500V dc

12 Pulse Rectifier

Vdc 12 Pulse

Transformer Secondary Windings

Phase Displaced

Overhead Line or Third Rail

Return Running Rails

Switch Gear and Busbars

Parallel Interface Transformer

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Rectifier Protection

Short Circuit Protection short circuit, overloading: thermal

relay and over current time relay. Internal Short Circuits

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

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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.

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Substation Electrical Performance

1. World System Voltages 2. HV Supply Arrangement 3. Distribution of DC Traction Supply 4. D.C. Feeding Arrangement 5. Trackside DC Substation Design 6. Substation Electrical Performance 7. Traction Return Current 8. Earthing 9. Regeneration 10. DC Magnetic Fields 11. Cable Specification 12. Induced Voltage 13. Lightning Protection 14. Disturbance effects

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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

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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

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Fault Profile

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2 DC Traction supply voltage European regulation EN 50163

Table 1 Definition of operating d.c. System Voltages

600* 750 1500 3000

lowest non permanent voltage duration 10min, lowest permanent voltage duration indefinitely, 400 500 1000 2000 nominal voltage designed system value, 600 750 1500 3000 highest permanent voltage duration indefinitely 720 900 1800 3600 highest non permanent voltage duration 5 min. 770+ 950^ 1950 3900

Ref[1] EN50163[Table 1,]

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3 Voltage Regulation with Track Sectioning Hut

I/4

I/4

33/11kV Supply

Feeder Station

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

Power Transformer


Rectifier Unit



I/4

I/4

33/11kV Supply

I/4 I/4

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4 Short Circuit with track Parallel Hut

Ib/4

Ib/4

Ib/4

Ib/4

Ib/2

Ib/2

Ia Ia

Ia +Ib

Ia +Ib

33/11kV Supply 33/11kV Supply

Feeder Station

Ib/2

Rail current Ib /4 if both rails available

Power Transformer


Rectifier Unit



Ia +Ib

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DC Short Circuit Current Waveform

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LUL Double DC earth fault >100kA

Double Pole Earth Fault Rail leakage

Bleed Resistors

Double Earth Fault

Rail Leakage

250 Ohm

125 OhmRail

Leakage Rail

Leakage

+420V

-210V

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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

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6 Production of AC and DC Characteristic Harmonics

Pulse Number DC Harmonics AC Harmonics

p np np ± 1

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0,6,12,18,24 1,5,7,11,13,17,19,23, 25

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0, 12, 24

1, 11,13, 23,25

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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% [UK]

275 and 400kV 3% 3.5% [UK]

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Rectifier Performance Characteristics

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Traction Return Current



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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;

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Typical Earthing Diode Earthed Railway

Substation Rectifier

Vrail

Distance

Diode Earth

Traction Current


DC System Voltage

Catenary

Main Earth bar VrailVrail Vrail

Substation Rectifier

Vrail

Distance

Traction Current


DC System Voltage

Catenary

Main Earth bar

VrailVrail Vrail

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Testing rail insulation

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Rail and Utility Potentials

Rail Return

Traction Current Catenary

Vdc

Rail Resistance

Remote Ground

Leakage Resistance

Potential of Rails Scale in 10(s) Volts

Potential of Utility with Interference

Scale in 100(s) mV

Corrosion

Utility

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Traction Earthing

1. World System Voltages 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. Traction Earthing 9. Regeneration 10. DC Magnetic Fields 11. Cable Specification 12. Induced Voltage 13. Lightning Protection 14. Disturbance effects

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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

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Earthing Standards European and National

UK and European 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

LUL Standards 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

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Typical DC Electrification Earthing Arrangement

NGC Substation

Earth Wire

DC Voltage

© R D White 2007

SignallingPSU

Track circuit

Telecoms. Cable

Tunnel Structure

Telecoms PSU

Rebars

Copper Earth Mat

Distribution Network Operator Supply

Track Structures Local

RECS

Station Apparatus

Station Metallic

Structures

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Depot Bonding Arrangement

Bogie Drop

DPS

LMS Rails EarthedOCS 1500V

DPS

HMS Rails Earthed OCS 1500V

Wheel lathe

Crane

Lift Jacks

DC Sub Station

AC Sub Station

Floating Earthed

HMS & LMS400sqmm cables

SS & Car Wash &Approach Roads400sqmm cables

OVPD

Test Track

E&M earth

Fault Path Protection LMS 1500V earth fault to rails: Structure bond/rails/return bonds dc breakersSS 1500 V earth fault rails Return bonds dc breakersLMS 1500V earth fault to structure Rails Return Bonds dc breakers SS 1500 V earth fault structure Fault Return Path OVPD& DC BreakersCar Wash 1500 V earth fault structure Fault Return Path OVPD& DC Breakers

Fault Path ProtectionHMS 1500V earth fault to rails Return Bonds dc BreakersHMS 1500 V earth fault structure Structure bonds/Rails/return Bonds dc Breakers

Fault return path

Traction Bond

M&E Earth M&E earth

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

Stabling Shed (SS) 20 Roads

Rails Floating OCS1500V

Main Earth Bar minimum 400mm2



Infrastructure and Maintenancerails earthed No 1500V

Car Wash OCS 1500 V


Our Ref: DC Depot Bonding.vsd

Revision Record

1

14/1

2/09

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

Project: MMMP

Issue: 1 14 Dec 2009Drawn by: R D White Checked by: Approved by: D Ellis

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.

Propsed new location of the IRJ

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System Earthing

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Bonding in Tunnel Structures (Dubai)

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0.016

0.031

0.063

0.125

0.250

0.500

1.000

2.000

0 10 20 30 40 50 60 70 80 90 100

Res

ista

nce

(MΩ

)

Humidity (%)

Monitoring on PSD Isolation Test

Civil Insulation PSD

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‘Stray Current Collection’

Rail Return

Traction Current Catenary

Vdc

Rail Resistance

Remote Ground

Leakage Resistance

Potential of Rails Scale in 10s Volts

Potential of Utility with InterferenceScale in 100s mV

Corrosion

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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

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North London Lines AC DC Operation

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Regeneration


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Regenerative Traction Units and Supply Points

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;

Rheostatic brakes on Croydon Trams

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DC Magnetic Fields


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Magnetic Electric Fields and Overhead Lines

ELECTRIC FIELD 1500V DC Roger D White WS Atkins Rail

EmagField

Magnetic Field Amps/m

1500V DC twin track 3000A per track Electric Field Volts/m

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Cable Specification


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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]

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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

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Induced Voltage


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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

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Lightning Protection


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Lightning Protection

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

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Disturbance effects



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Disturbance Effects of DC Electrification Systems

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

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

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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

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DC Railway Electrification System Design Railway Electrification

Infrastructure School

Dr Roger D White [email protected]

System June 2013

reis - roger white dc presentation

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