ELECTRIC TRACTION SUELECTRIC TRACTION SUELECTRIC TRACTION SUELECTRIC TRACTION SUBSTATIONS STUDY OF BSTATIONS STUDY OF BSTATIONS STUDY OF BSTATIONS STUDY OF RAILWAYRAILWAYRAILWAYRAILWAY

Valentin IEREMIE Ştefan cel Mare University of Suceava

Radu-Dumitru PENTUC Ştefan cel Mare University of Suceava

Cezar-Dumitru POPA Ştefan cel Mare University of Suceava

Florin BERNEA

Carpatcement Holding

REZUMAT. REZUMAT. REZUMAT. REZUMAT. Studiul substaţStudiul substaţStudiul substaţStudiul substaţiiloriiloriiloriilor electriceelectriceelectriceelectrice de de de de ttttracţracţracţracţiune iune iune iune îîîîn contextul actual este deosebn contextul actual este deosebn contextul actual este deosebn contextul actual este deosebit de important, prin specificul traficului it de important, prin specificul traficului it de important, prin specificul traficului it de important, prin specificul traficului feroviarferoviarferoviarferoviar,,,, care in ultima perioada a cunoscut o semnificativa reducere.care in ultima perioada a cunoscut o semnificativa reducere.care in ultima perioada a cunoscut o semnificativa reducere.care in ultima perioada a cunoscut o semnificativa reducere. Producţia de mărfuriProducţia de mărfuriProducţia de mărfuriProducţia de mărfuri industrialeindustrialeindustrialeindustriale ssss----a dia dia dia diminuat mult în ultimi ani.minuat mult în ultimi ani.minuat mult în ultimi ani.minuat mult în ultimi ani. Transportul atat a marfurilor, cat si pentru calatori, Transportul atat a marfurilor, cat si pentru calatori, Transportul atat a marfurilor, cat si pentru calatori, Transportul atat a marfurilor, cat si pentru calatori, a fost preluat in mare parte dea fost preluat in mare parte dea fost preluat in mare parte dea fost preluat in mare parte de tracţiunea auto. Iată de ce puteri instalate in substatii tracţiunea auto. Iată de ce puteri instalate in substatii tracţiunea auto. Iată de ce puteri instalate in substatii tracţiunea auto. Iată de ce puteri instalate in substatii de tractiunede tractiunede tractiunede tractiune feroviareferoviareferoviareferoviare nu mai sunt utilizate in prezent la capacitatea proiectata. nu mai sunt utilizate in prezent la capacitatea proiectata. nu mai sunt utilizate in prezent la capacitatea proiectata. nu mai sunt utilizate in prezent la capacitatea proiectata. EEEEste de inters analiza eficientei energetice la aceste ste de inters analiza eficientei energetice la aceste ste de inters analiza eficientei energetice la aceste ste de inters analiza eficientei energetice la aceste instalatii, cu preponderenta studiul comportarii transformatoarelor de putere, in constructie speciala, care echipeaza acesteinstalatii, cu preponderenta studiul comportarii transformatoarelor de putere, in constructie speciala, care echipeaza acesteinstalatii, cu preponderenta studiul comportarii transformatoarelor de putere, in constructie speciala, care echipeaza acesteinstalatii, cu preponderenta studiul comportarii transformatoarelor de putere, in constructie speciala, care echipeaza aceste substatii substatii substatii substatii don tractiunea feroviară.don tractiunea feroviară.don tractiunea feroviară.don tractiunea feroviară. Cuvinte cheieCuvinte cheieCuvinte cheieCuvinte cheie: viteza de circulaţie, protecţii, tractiune electrica, infrastructura, sectiuni de linie, statii, circuite secundare, substatii, transformator. ABSTRACT. ABSTRACT. ABSTRACT. ABSTRACT. The electric substation traction study in present context is particular important in specific rail trafic, wich lately has seThe electric substation traction study in present context is particular important in specific rail trafic, wich lately has seThe electric substation traction study in present context is particular important in specific rail trafic, wich lately has seThe electric substation traction study in present context is particular important in specific rail trafic, wich lately has seen en en en a significant reduction. Production of industrial goods has declined a significant reduction. Production of industrial goods has declined a significant reduction. Production of industrial goods has declined a significant reduction. Production of industrial goods has declined over the pastover the pastover the pastover the past years.years.years.years..... Transport both cargo and for passengers Transport both cargo and for passengers Transport both cargo and for passengers Transport both cargo and for passengers was taken over bz the traction motor. That is whz installed capacitz in railwaz traction substation are not currentlz usedwas taken over bz the traction motor. That is whz installed capacitz in railwaz traction substation are not currentlz usedwas taken over bz the traction motor. That is whz installed capacitz in railwaz traction substation are not currentlz usedwas taken over bz the traction motor. That is whz installed capacitz in railwaz traction substation are not currentlz used to design to design to design to design capacitz. It is interesting to analzye the energz efficiencz of these plants, mainlz studzng the behaviour of power transformcapacitz. It is interesting to analzye the energz efficiencz of these plants, mainlz studzng the behaviour of power transformcapacitz. It is interesting to analzye the energz efficiencz of these plants, mainlz studzng the behaviour of power transformcapacitz. It is interesting to analzye the energz efficiencz of these plants, mainlz studzng the behaviour of power transformers units, ers units, ers units, ers units, in special construction, which equips the electrical substation traction. in special construction, which equips the electrical substation traction. in special construction, which equips the electrical substation traction. in special construction, which equips the electrical substation traction. KeywordsKeywordsKeywordsKeywords: technical speed, automatic block line protection, electric traction, infrastructure lines, line sections, plants, secondary circuits, substations, transformer.

1. INTRODUCTION

Fixed installations for electric traction (IFTE) Romanian Railways have been built during 1965-1991. 78 traction substations and over 10,500 miles of wire contacts held currently define the size of these facilities.

In our country, the design and the construction of

fixed installations for the electric traction had been

created in a very unfavorable time period, characterized

by a general policy of austerity-oriented savings

becoming more severe and more reduced execution

times. Exploitation, misuse of the 80s (too intense and

marked by frequent interruptions in electricity supply

traction substations) contributed to the physical and

moral wear of primary and secondary apparatus, which

was passed anyway because it had been built on

technology from the 70s. All these shortcomings have

led to their operation and minimal technical conditions

financial efforts.

In Romania, the Railways, to supply electricity to

the catenary a single-phase traction 25kV-50Hz system

was adopted, supplied from the local grid of 110 kV.

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2. TRANSFORMATION STATIONS

The energy system includes all facilities for

producing energy in a usable form, convert it into

electricity and sometimes combined heat and power,

transport, processing, distribution and use of electricity

or heat. All the elements of the energy system are

characterized by a coordinated process of generation,

transmission, distribution and consumption of

electricity or heat.

The power system is a set of plants, substations,

transformer substations and power receivers, connected

by a grid lines. Electric power system is the energy

system and includes facilities for producing electricity

(generators), processing plants, to a voltage to another

(and transformer stations), transmission facilities and

distribution of electricity (network high, medium and

low voltage) and use its facilities.

The electricity produced by power plants suffer

more changes in blood to be transported with low losses

as large as distances and then used by consumers.

Transmission of electricity from large and very large

distances (ie tens to hundreds of kilometers) have been

so high on power lines and very high voltage (110, 220,

400, 750 kV). Transmission of electricity at relatively

small distances (of the order of kilometers or at most a

few tens of kilometers), is made with medium voltage

lines (6, 10, 20 kV) and at very short distances

(hundreds of meters), the low voltage lines (0.4 kV).

The higher voltage is much lower current and therefore

losses (own consumption, CPT) for transmission of

electricity, much lower because they are proportional to

the square of current.

Conversion voltage levels (the transportation of

electricity as low loss with power lines), taking place in

the stations and substations, which are nodes of the

power system and power lines are connected.

3. ELECTRIC TRACTION SUBSTATIONS

In the past 20 years have seen an extraordinary

development in the field of electric traction. This was

accompanied and determined by the pace of

development of power electronics and microprocessors,

which led to fundamental changes in design,

construction and operation of electric traction. Due to

the rapidity with which these changes have been made,

there is currently co-existence of many different types

of traction systems.

Electric vehicles powered by the contact line

(autonomous vehicles, which energy source is not a

vehicle) requires a series of plants along with them,

form a system of electric traction. In Fig. 1. presents the

main equipment of an electric traction system.

The production, transport and distribution of

electricity installations are made up of: electric power

(hydro, thermal, nuclear, wind), substations, power

lifting SRT and high voltage overhead power lines LIT

(110 kV, 220 kV, 440 kV) for long distance

transmission of electricity. Note that these facilities are

not specific to electric traction.

LITSRT SRTCE CE

ST ST

PLP

LC

ZN

LC

V

CR

CICA

CACI

PSS PS

BP BP

BN BN

Fig. 1. The traction system schema

The traction substations creates the connection to

the national power or high voltage power system's own

track, and power adjustment parameters (voltage,

current, frequency) on standardized values necessary to

the contact line LC.

LC line of contact - network overhead is mounted

above the tread and the vehicle takes power through a

current collector or collector. Note that some vehicles

are powered by a rail contact, located at ground level.

CR rolling path - is metallic raceway (the rail) for

railway vehicles, trams and subways, and taking her

current role back to the traction substation. For some

vehicles path can be concrete or asphalt (buses) or can

be mixed (for some metro). Power cables are overhead

lines, which bars a link between low voltage (the

positive bars BP) of traction substations and line

contact.

ZN neutral zone - is a zone of separation of portions

of the contact line fed from different phases of the

power system.

PS sectioning stations - allow connections or

longitudinal sectioning of the contact line between two

substations, traction, thereby limiting the area that a

fault can occur. Longitudinal sectioning may be

additional and PSS subsections stations located between

substations and sectioning posts. In addition, if double

taxiways, PS and PSS and binding done in parallel lines

on the two-way contact, which improves by decreasing

the tension in catenary’s voltages. If there are no jobs

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PSS is by linking parallel channels in parallel PLP

binding.

CI cables - back the closing of the electrical

circuit. They make the connection between the return

current path (track) and the low voltage traction

substation (the negative bars BN).

V - electric vehicle takes power from the line of

contact through the sensor, which converts energy into

mechanical energy to the rim driving wheels, which

provides a vehicle to move.

Traction system c.c. is the contact line system is

powered by DC. The system is used both in urban and

electric traction railway electric traction. The schematic

diagram is shown in Figure 2.

Traction substations are supplied from the power

lines of three phase power system of 110 kV or 220 kV

and 50 Hz. In sub-phase voltage reduction takes place

through a step-down transformer to convert current

values and the phase alternating current. For the greater

power in substations are generally two groups of force,

one in operation and the other is reserve.

Introduction recuperative braking vehicles was an

important step towards increased energy efficiency of

transportation systems.

BP

PS

TCTC

RD RD

BN

BP

BNCACICI CA

CR

LC c.c.

PS

PS

LIT 50 HzST ST

Fig. 2. C.c. traction system

To eliminate this case, the traction substation may

be equipped with inverters (Fig. 3). Thus the contact

line is fed from a rectifier, and when the vehicle

exceeds the power recovered along the route, the

inverter is automatically activated and the system

transfer energy high voltage. Of course, this system

requires a significant additional investment, which

requires a careful economic study. VEM party structure

with the mechanical grip unguided path (road) is shown

in Figure 4.

On the front axle steering is installed (including

steering wheel, gear drives, roller and articulated lever

system) which is achieved by transferring the front

wheels, thus guiding the CR VEM.

Fig. 3. SSTE with energy recovery

The main transmission drive axle is installed

(including gear reducers, mechanical differential and

planetary axes), allowing different speeds of the left-

right wheel drive axle, to prevent excessive tire wear

and power consumption.

Fig. 4. VEM’s mechanical parts

The frame, representing a welded construction,

made of rolled steel and sections, which supports body

VEM and the two bridges connecting the elastic

suspension with leaf springs.

The articulated trolleybus, the second axle is the

driven normally. With the development of this type of

trolley was possible involvement of the third with three

axles or motors, either through a purely mechanical

solution, in which both motors are axle shafts driven

through by a single engine. Diode Block 2 consists of

two groups of diodes connected in series, each group

containing two parallel diodes used for two operating

modes of the vehicle (driving, braking respectively).

Traction motor is a DC motor with series

excitation in insulation class F, drive vehicles

intended for urban traction TN 76. The motor is

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directly supply the contact line, the voltage is equal

to its nominal rated motor voltage.

Romanian electric locomotive 060-EA-LE has

been designed for single-phase AC power, 50 Hz and

27 kV, with a power of 5100 kW distributed over the

six electric motors of 850 kW each.

Fig. 6. AC locomotive power scheme phase

Rolling machine, which is based on CR, is

composed of 12 six-axle tractors and engines,

distributed evenly over the two bogies.

The two bogies are connected by a flexible

coupling, so that their rotation can be horizontal to

the box, for easy inclusion curve. Given the principle

of constructive mechanical part of the electrical

engine axle formula for this is C'0 - C'0, which means

that the running of the locomotive apparatus

comprises two bogies, each with three individually

driven axles.

Main circuit-breaker (circuit breaker) is an

instrument which carries the general disruption of the

locomotive electrical circuits, providing protection

from overloads and short circuits.

The arrester is provided with variable resistance in

the electrical equipment of locomotive air surge

protection (which can reach hundreds of kV with

duration of the order microseconds) and voltage

switching (to lower values but longer). Circuit is

mounted in parallel between power and ground.

Rectifier diodes that allow the recovery schemes

using both alternations. Practical schemes are those

with mid-point or single-phase diode bridge.

Traction motors are DC motors series, number 6.

AC electric locomotive speed control phase, 50 Hz,

25 kV. AC locomotives phase speed control is obtained

only by varying widely voltage from a minimum

value to its nominal value and to broaden the scope of

regulation, the last step voltage, and a few steps longer

apply reduced field.

Schematic diagram of the circuit under braking

rheostat generator with separate excitation is shown in

Figure 7. Changing the excitation current is achieved by

gradually. Lockouts separator’s handling SSB1T if not

open-3T cells related breaker 27.5 kV transformer 1T,.

Fig. 7. Schematic diagram of the braking circuit rheostat

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Fig. 8. Suceava electric traction substation plan.

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4. SUCEAVA TRACTION SUBSTATION

Suceava traction substation is located on the left

side of the railway line Burdujeni Suceava - Suceava

Nord km. 448 300 (ax path processors) being designed

to supply the normal operation of the contact line

Suceava Nord station and distances:

- STE-Suceava Suceava Vest - Stroieşti PS;

- STE-STE Dolhasca Suceava;

- STE Suceava - Dărmăneşti - PS Todireşti.

In terms of the primary circuit scheme is being

fueled by double-phase type with a pipe branch of

110/20 kV double circuit Iţicani Main parts:

- Primary circuit - were designed to make the

transfer of power between the 110 kV high voltage line

and the line of contact.

- Secondary circuits - Includes circuits for

controlling, blocking signaling, measuring, protection

and automation.

- Equipment associated with secondary circuits are

arranged in panels placed in the control room.

- Own Services - are only meant to ensure

continuous supply of alternating current and secondary

circuits.

Forming an outer ring located 1.5 m contour of the

fence. On the outer ring road contour vertical electrodes

are disposed at a distance of 6 m apart.

All connections between devices and the earth

electrode are twofold.

Also at the substation earth electrode and the link

connecting the copper plate feeder back from the three

transformers. Protection apparatus mounted outside the

control room to support the construction of the control

unit against direct lightning strikes lightning rods is

achieved by frame mounted on poles.

Secondary circuits are: control circuits as follows::

control switches in cell IO 110 kV substation;

secondary electrical circuits MOP-1 mechanism; switch

control cells IUP 27.5 kV substation; control switches

in cell feeder nF; order separators feeders; transfer of

command separators feeders STF3 STF1-2-4; order

separators SLFn feeders; 27.5 kV command connecting

separators; 27.5 kV semiconductor command

separators, and SSB2T SSB1T-3T-1T; control of cell

separators 27.5 kV substation; control of air separators

blade (SLA); 110 kV command separator; order knives

grounding semi connecting 27.5 kV; earthling knives

command of the bay feeder nF; tap changer control,

circuits of blocking.

5. CONCLUSIONS

In conclusion I want to highlight the importance of the power factor in a fixed electric traction installation. For example, if electric traction substation of Suceava there are three power transformers, of which only one is operating, the other two being in reserve. When less electric vehicles are operating, the traction power transformer will operate at a reduced load, or even empty. For this it is desirable to have reactive power compensation equipment required by the transformer. The most popular method of improving power factor at a low voltage distribution system is the use of power capacitors. Capacitor's size and location has to be determined and corrected by calculations. In general these have to be connected as close as possible to the load.

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