siemens gis

7/30/2019 Siemens GIS

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Power Transmission and Distribution

Gas-Insulated Switchgear

up to 145 kV

Type 8DN8


2/18

Benefitting from Experience

2

Durch die Feldteilung

von nur 0,8 m wird

der Raumbedarf un-

serer 8DN8 auf ein

Minimum reduziert

The operator panel of

the processor bus bay

control system is inte-

grated into the oper-

ating front of the bay

8DN8 switchgear

for rated voltages

up to 145 kV

Both plug-in type and

conventional cable

sealing ends can be

used in conjunction

with type 8DN8

switchgear

Our 8D type range of gas-

insulated switchgear represents

a highly successful product

concept. Since its introduction

back in 1968, Siemens has

installed more than 8000 bays

worldwide. More than 100,000

bay-years of operation have since

been recorded.Intensive research work and

continuous further development

of the prototypes has ultimately

led to todays generation of gas-

insulated metal-enclosed

switchgear. This switchgear is

notable in particular for:

Economic efficiency

High reliability

Safe encapsulation

High degree of gas-tightness

Minimal operating costs

No maintenance Good accessibility

High availability and

Long service life.

All requirements nowadays

specified for modern and

advanced switchgear in terms of

performance and reliability are

met by our type 8DN8

switchgear for rated voltages of

up to 145 kV. This switchgear

design represents one of the most

compact solutions available in this

voltage range. Its space-savingdesign and its low weight

contribute to making this

switchgear extremely econom-

ical. Since the levels of noise and

field emission (EMC) are ex-

tremely low, it is possible to

integrate this switchgear even in

sensitive environments,

residential quarters and city

centers.

With these characteristics, our

type 8DN8 switchgear meets all

the requirements forenvironmentally compatible high-

voltage switchgear.


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3


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1 Interrupter unit of the

circuit-breaker

2 Spring stored-energy

mechanism with circuit-

breaker control unit

3 Busbar I with discon-

nector and earthing

switch4 Busbar II with discon-

nector and earthing

switch

5 Outgoing feeder module

with disconnector and

earthing switch

6 High-speed earthing

switch

7 Current transformer

8 Voltage transformer

9 Cable sealing end

10 Integrated local control

cubicle

Three-phase enclosure

allows compact design

Efficient

Due to Modular Design

4

M

M

x

M

M

x

M

Temperature-related changes

in the length of the enclosure

and installation tolerances

are compensated by bellows-

type expansion joints. The

conductors are linked by

coupling contacts. Where

necessary, the joints are

accessible via manway open-

ings. Gas-tight bushings allow

subdivision of the bay into

a number of separate gas

compartments. Each gascompartment is provided with

its own gas monitoring equip-

ment, a rupture diaphragm

and filter material. The static

filters in the gas compart-

ments absorb moisture and

decomposition products.

A fundamental feature of our

gas-insulated switchgear is

the high degree of versatility

provided by its modular

system. Depending on their

respective functions, the

components are housed

either individually and/or

combined in compressed-gas-

tight enclosures. With a

remarkably small number of

active and passive modules,

all customary circuit variantsare possible. Sulphur hexa-

fluoride (SF6) is used as the

insulating and arc-quenching

medium.

Three-phase enclosures are

used for type 8DN8 switch-

gear in order to achieve

extremely low component

dimensions. This concept

allows a very compact design

with reduced space require-

ment. Aluminium is used for

the enclosure. This assures

freedom from corrosion and

results in low weight of

the equipment. Through the

use of modern constructionmethods and casting tech-

niques, it has been possible

to optimize the dielectric and

mechanical characteristics of

the enclosure. The low bay

weight ensures minimal floor

loading and eliminates the

need for complex foun-

dations. All the modules are

connected to one another by

means of flanges. The gas-

tightness of the flange con-

nections is assured by provenO-ring seals.

4

7

9

8

10

5

2

3

1

6

Gas-tight bushing

Gas-permeable bushing

The rupture diaphragms

prevent build-up of an im-

permissible high pressure in

the enclosure. A gas diverter

nozzle on the rupture dia-

phragm ensures that the gas

is expelled in a defined direc-

tion in the event of bursting,

thus ensuring that the oper-

ating personnel is not

endangered.


5/18

5


6/18

and compresses the re-

maining arc-quenching gas.

The compressed arc-quench-

ing gas flows through the

contact cylinder (5) into the

contact gap and extinguishes

the arc.

Interruption of fault current

If the short-circuit current is

high, the arc-quenching gas

at the arcing contact is heated

up considerably by the energy

of the arc. This leads to a

pressure rise in the contact

cylinder. Consequently, the

energy required for produc-

tion of the arc-quenching

pressure does not have to be

supplied by the operating

mechanism. As the switching

operation progresses, the

fixed arcing contact releases

the outflow from the nozzle

(2). The gas now flows out

of the contact cylinder and

through the nozzle, thus ex-

tinguishing the arc.

Breaker in

On position

Breaking:

Main contact

open

Arc-quenching principle

6

The central element of the


the three-pole circuit-breaker

module enclosure comprising

the following two main

components:

Interrupter unit

Operating mechanism

The design of the interrupter

unit and of the operating

mechanism is based on pro-

ven and in most cases iden-

tical designs, which have

often been applied for

outdoor switchgear

installations.

Circuit-breakermodule

Interrupter unit

The interrupter unit used in

the circuit-breaker for arc-

quenching operates on the

self-compression principle.

Owing to the low amount of

drive energy required, the

mechanical forces involved

are minimal. This has a posi-tive effect on the stressing

of both the circuit-breaker and

the enclosure.

1 Contact support

2 Nozzle

3 Main contact4 Arcing contact

5 Contact cylinder

6 Base

1

2

3

4

5

6

The current path

In the case of a self-compres-

sion circuit-breaker, the

current path is formed by the

contact support (1), the base

(6) and the moving contact

cylinder (5). In the closedcondition, the operating

current flows through the

main contact (3). An arcing

contact (4) is connected in

parallel to the main contact.

Interruption of

operating current

During the breaking

operation, the main contact

(3) opens first and the current

commutates on the arcing

contact (4), which is stillclosed. By this means, erosion

of the main contact is

avoided. As the breaking

operation progresses, an arc

develops between the

contacts (4). The contact

cylinder (5) moves

simultaneously in the base (6)

Circuit-breaker module


7/18

1 On release

2 Cam disc

3 Corner gears

4 Drive linkage

5 Connecting rod

of the closing

spring

6 Connecting rod

of the opening

spring

7 Closing spring

8 Manual charging

crank

9 Charging

mechanism

10 Charging shaft

11 Roller lever

12 On damper

13 Breaker actuatingshaft

14 Off damper

15 Off release

16 Operating

mechanism

housing

17 Opening spring

Use is made of proven design

principles of Siemens circuit-

breakers, such as, for ex-

ample, vibration-proof latches

and load-free decoupling of

the charging mechanism.

The operating mechanism

offers the following advan-

tages: Defined switching position

which is securely

maintained even when the

auxiliary power supply fails

Tripping is possible irrespec-

tive of the status of the clos-

ing spring

High number of mechanical

operations

Low number of mechanical

parts

Compact design.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

7

Operating mechanism

The spring stored-energy

operating mechanism pro-

vides the force for opening

and closing the circuit-

breaker. It is installed in a

compact corrosion-free

aluminium housing. The

closing spring and theopening spring are arranged

so as to ensure good visibility

in the operating mechanism

block. The entire operating

mechanism unit is completely

isolated from the SF6 gas

compartments.

Anti-friction bearings and a

maintenance-free charging

mechanism ensure many

years of reliable operation.

Breaking:

Arcing contact

open

Breaker in

Off position


8/18

Outgoing feeder module

The outgoing feeder module

connects the basic bay with

various termination modules

(for cable termination, over-

head line termination and

transformer termination).

It contains a three-position

switching device, whichcombines the functions of

an outgoing feeder

disconnector and of a bay-side

earthing switch (work-in-

progress type).

Installation of a high-speed

earthing switch and of a

voltage transformer is also

possible, where required. The

high-voltage site testing

equipment is generally

connected to this module.

Busbar module

Connections between the

bays are effected by means of

busbars.

The busbars of each bay are

enclosed. Adjacent busbar

modules are coupled by

means of expansion joints.

The module contains a three-position switching device,

which combines the functions

of a busbar disconnector and

of a bay-side earthing switch

(work-in-progress type).

The moving contact either

closes the isolating gap or

connects the high-voltage

conductor to the fixed contact

of the earthing switch. Inte-

gral mutual interlocking of the

two functions is achieved as

a result of this design, thus

obviating the need for provi-sion of corresponding elec-

trical interlocking within the

switchgear bay. An insulated

connection to the fixed con-

tact of the earthing switch is

provided outside the enclo-

sure for test purposes.

In the third neutral position

neither the disconnector

contact nor the earthing

switch contact is closed.

The three poles of a bay are

mutually coupled and all the

three poles are operated in

common by a motor.

Force is transmitted into the

enclosure via gas-tight rotat-

ing shaft glands. The check-

back contacts and the on-off

indicators are mechanically

robust and are connected

directly to the operating shaft.

Emergency operation by hand

is possible. The enclosure can

be provided with inspection

windows, in the case of which

the On and Off position ofall three phases is visible.

Neutral position

Disconnector closed

Earthing switch closed

The functions of a disconnec-

tor and of an earthing switch

are combined in a three-

position switching device.

Busbar module

Outgoing feeder module:

Voltage transformer down-

stream of the disconnector

Outgoing feeder module:

Voltage transformer

upstream of the disconnector

Three-position

switching device

Schematic diagram


9/18

Bus sectionalizers

Bus sectionalizers are used for

isolation of the busbar

sections of a substation. They

are integrated in the busbar

in the same manner as a

busbar module.

The module contains a three-

position switching device,which combines the functions

of a bus sectionalizer and of

an earthing switch (work-in-

progress type).

Voltage

transformer module

The voltage transformers

operate on the principle of a

voltage divider. Induction-

type voltage transformers can

be used as an alternative. The

voltage transformers can be

installed either upstream ordownstream of the outgoing

feeder disconnector or at the

busbar. The secondary-side

connections are led out of the

enclosure through a gas-tight

bushing plate and are made

available at terminals in the

integrated local-control

cubicle.

Bus sectionalizer High-speed earthing switch

9

The high-speed earthing

switch used is of the so-called

pin-type. In this type of

switch, the earthing pin at

earth potential is pushed into

the tulip-shaped fixed contact.

The earthing switch is equipped

with a spring-operated

mechanism, charged by anelectric motor.

Both current and voltage

transformers are used for

measuring and protection

purposes. They are supplied

in a number of variants

ranging from conventional

instrument transformers to

advanced current and voltage

sensors.

Current

transformer module

As a general rule, power op-

timized inductive-type current

transformers are used. The

current transformer can,

however, be located at any

point within the bay or sub-

station. The high-voltage

conductor, supported by gas-

tight bushings, forms the

primary winding. The coreswith the secondary windings

are designed in line with the

requirements in terms of class

precision and rating.

Changeover to a different

transformation ratio is pos-

sible by means of secondary-

side connections of the

current transformer, which

are led out of the enclosure

through gas-tight bushings

and are made available at

terminals in the integratedlocal-control cubicle.

High-speed

earthing switch

Example: power-optimized

voltage transformer module

Example: power-optimized

current transformer module

Instrument

transformers


10/18

Angular module

Angular modules are used for

splitting of the conductors

in outgoing leads. They are

available in designs with

angles of 30, 45, 60 and

90.

T-module

T-modules are used as

branch-off point or for attach-

ment of a surge arrester.

They are available in various

designs; however, their basic

form is always identical.

Extension module

Single-poleextension module

Three-poleextension module

Three-pole 90angular module

Design variants of single-pole angular modules

Design variants of single-pole T-modules

0

Connection

modules

Splitting modules,

single-pole/three-pole

Splitting modules

These modules are used to

make the required joints

within a bay and for pipework

penetrations. Both single-pole

and three-pole enclosed con-

nection modules are available.

The following connection

modules can be used,

depending on the circuit andthe spatial layout of the bay:

The splitting modules are used

for connection of three-pole

plant components to single-

pole components. As a rule,

they serve as connections

between the outgoing feeder

module and various termi-

nation modules (for overhead

line termination, transformertermination).


11/18

The termination modules

connect the bays of the gas-

insulated switchgear to the

following items of equipment:

Overhead line

Transformer or reactor coil

Cable.

They function as the transition

link from the SF6 gas insula-

tion within the enclosure to

other insulating media.

Cable termination module

This three-pole module links

the metal-enclosed gas-

insulated switchgear with a

high-voltage cable. All cus-

tomary kinds of high-voltage

cables can be connected. The

primary conductor connection

between the cable sealing endand the switchgear can be

removed in the neighbouring

outgoing feeder module in

order to allow a high-voltage

withstand test to be performed.

Both conventional type cable

sealing ends and plug-in types

can be used.

Outdoor

termination module

The single-pole outdoor ter-

mination module forms the

transition from the gas-

insulated switchgear to air-

insulated components or

overhead lines. This termina-

tion is a combination of asingle-pole connection

module and an outdoor/SF6bushing. Length, shielding

form and creepage distance

of the outdoor/SF6 bushing

are determined in line with

insulation coordination, mini-

mum clearance and degree of

pollution. The outdoor

termination module is suitable

for air-insulated connections

between GIS and:

Overhead lines Outdoor bushings of out-

door transformers or reactor

coils

Outdoor sealing ends of

high-voltage cables.

The splitting of the

connection points for the

three phases with the

necessary clearance in air for

conductor insulation is taken

into account in the design of

the switchgear.

Transformer

termination module

The single-pole transformer

termination module is con-

nected (in a similar manner

to the outdoor termination)

to the three-pole enclosed

basic bay via a combination

of connection modules. It ef-fects the transition from the

gas insulation directly to the

bushing of oil-insulated

transformers or reactor coils.

The transformer bushing must

be oil-tight and resistant to

gas pressure.

Temperature-related move-

ments and non-uniform sett-

ling by the foundations of

switchgear and transformer

are absorbed by expansion

joints.

11

Termination

modules

Surge arrester

module

If required, enclosed surge

arresters can be connected

directly. They serve to limit

the occurrence of overvolt-

ages. Their active part con-

sists of metal-oxide resistors

with strongly non-linear

current/voltage characteristics.

The arrester is generallyflange-jointed to the switch-

gear via a gas-tight bushing.

The tank of the arrester

module incorporates a man-

way opening, through which

the internal conductor can

be accessed for inspection

purposes. There are connec-

tions for gas monitoring and

arrester control devices on the

underside.

Example: Cable termination

module (plug-in type)Surge arresterOutdoor termination module Transformer

termination module


12/18

Proven and innovative switchgear control

All the elements required for control and monitoring are accom-

modated in a decentralized arrangement in the high-voltage

switching devices. The switching device control systems are factory-

tested and the switchgear is usually supplied with bay-internal

cabling all the way to the integrated local control cubicle. This

minimizes the time required for commissioning and reduces the

scope for possible faults.

As standard, the control and monitoring system is made up of

electromechanical components.

Alternatively, the digital intelligent control and protection system

SICAM HV including comprehensive diagnostics and monitoring

functions is available. More detailed information on the substation

state means that maintenance intervals can be geared to the

condition of the switchgear. Life-cycle costs can consequently be

reduced even further.

Operating mechanism

cubicle of the circuit-

breaker

Gas monitoring

Gas-tight insulating partitions divide each bay into functionally

destinct gas compartments (circuit-breaker, disconnector, voltage

transformer, etc.). The gas compartments are under constantobservation by means of density monitors with integrated indicator;

any non-conformity is immediately signaled. The optionally available

monitoring system with SICAM HV includes sensors that allow a

trend forecast for each gas compartment.

Flexible and reliable protection in bay and substation control

Control and feeder protection are generally accommodated in the

local control cubicle, which is itself integrated in the operating

panel of the switchgear bay. This substantially reduces the amount

of space required and also the time needed for commissioning.

Alternatively, a version of the local control cubicle is available for

installation separate from the switchgear. Various arrangements

of the control and protection components are consequentlypossible. The cabling between the separately installed local control

cubicle and the high-voltage switching devices is connected up

via coded plugs, which minimize both the effort involved and the

risk of errors.

If requested, we can of course supply high-voltage switchgear

featuring any customary bay and substation control equipment.

We provide uniform systems to meet your individual requirements.

Neutral interfaces in the switchgear control allow link-up of

A conventional control system with contactor interlocking and

control panel

Digital control and protection comprising user-friendly bay con-

trollers and substation automation with PC operator station (HMI) An intelligent, uniformly networked digital control and protection

system with supplementary monitoring and telediagnostics

functions.

From the wide range of Siemens control and protection equipment,

we can provide you a customized concept; everything comes from

a single source.

Integrated local control cubicle

Control and Monitoring Uniform and Flexible Control and Protection

2


13/18

To optimally facilitate

transport and installation on

site, our switchgear

assemblies are shipped in

units as large as possible, yet

still easy to handle. It is thus

possible to dispatch up to

three completely assembled

and tested switchgear bays,

prefilled with SF6 gas, as a

transport unit. In transport

units containing switching

devices, all operating

mechanism attachments are

preset in the factory prior to

shipment. The jointing points

of the transport units are

protected against corrosion

and are sealed with transportcovers. Goods are packed

according to means, duration

and route of transport, and

also in line with nature and

duration of storage.

Shipments within Europe are

normally transported by road.

Switchgear supplied to

countries outside Europe is

enclosed in sealed packing,

suitable for transport overseas

and for a combined duration

of transport and storage of upto 12 months. In special cases,

the sealed packing can also

be designed for a longer

period.

The delivery of complete

factory-assembled bays

significantly reduces the effort

required for installation on

site. The transport unit is

brought to its place of in-

stallation by means of simple

equipment and is aligned

ready for assembly with the

other bays. A mounting frame

facilitates movement and

rapid alignment of the bays.

Only a limited number of

anchorings and additional

steel supports is required for

securing the switchgear to the

foundation. Depending on the

bay design, only the bay

termination needs to beassembled. Only bay-to-bay

cabling has to be installed on

the secondary side.

Uncomplicated work proce-

dures, detailed installation

instructions and the use of

relatively few special tools

allow easy and rapid installa-

tion of the switchgear by your

own personnel under the

guidance of an experienced

supervisor from Siemens. Our

training facilities are at yourdisposal.

When the assembly work has

been completed, all switching

devices and all electrical cir-

cuits for control and moni-

toring are tested to ensure

that they function properly in

both mechanical and electrical

terms. Flange joints made on

site are tested for gas leaks.

All other flange joints are al-

ready factory-tested.

All tests are performed in

conformity with IEC. The

results are documented in

reports.

Our gas-insulated switchgear

is designed and manufactured

so as to produce an optimal

balance between design, ma-

terials used and maintenance

required.

The hermetically-sealed en-

closures and automatic moni-

toring ensure minimal switch-

gear maintenance; under

normal operating conditions

the assemblies are practically

maintenance-free. We recom-

mend that the first major in-

spection be carried out after

25 years.

Transport, Installation,

Commissioning, Maintenance

Transport Commissioning Maintenance

13

Installation

and erection

High-voltage test on site

Factory-assembled panel


14/18

The quality of Siemens


assured by an all-encompas-

sing, state-of-the-art quality-

management system. The

system was certified in 1983

in accordance with CSA Z299

and again in 1989 in accord-ance with DIN EN ISO 9001.

Quality assurance for us is

primarily a means to increase

the customer orientation of

our activities.

The quality assurance system

comprises all product life-

cycle sequences, ranging from

marketing to after-sales

service. Regular management

reviews, internal audits and

external audits of all proces-

ses ensure that the system iseffective and up-to-date.

Documentation of all quality-

relevant sequences forms

the basis. The quality of our

switchgear consequently

meets even the highest

requirements.

Consistent quality manage-

ment naturally also extends

to the production of our gas-

insulated switchgear. As-

sembly under clean-room

conditions, comprehensivemanufacturing inspections

and routine tests on individual

components and complete

modules assure reliable

switchgear operation. Follow-

ing mechanical routine tests,

the final quality verification

takes place in the form of a

high-voltage test on the

complete bay (or on the

transport units) prior to ship-

ment.

Quality Assurance

4


15/18

All the standard circuit con-

figurations can be realized

using our type 8DN8 switch-gear.

2850

3300

Bay weight approx. 2.8 t

Coupling bay

5

Typical

Bay Arrangement

H-configurationDuplicate busbar system

6400

3500

3500

M

MMMM

M

M

M

M MM

M

MM

M

M M MM M M

M

MM

M

MM

M

M

M

H-Configuration


16/18

3500

3100

2850

3500

Bay weight approx. 3.1 t Bay weight approx. 3 t

H-configurationOverhead line bay

16

Direct connection to the transformer

6700 3500

3100

Bay weight approx. 3.1 t

M

M

M MM

M


17/18

Technical

Data

17

Switchgear type 8DN8

Rated voltage up to 145 kV

Rated frequency 50/60 Hz

Rated power frequency up to 275 kVwithstand voltage (1 min)

Rated lightning impulse up to 650 kV

withstand voltage (1.2/50 s)

Rated busbar current up to 3150 A

Rated feeder current up to 3150 A

Rated breaking current up to 40 kA

Rated impulse current up to 108 kA

Rated short-time current up to 40 kA

Leakage rate per year and gas 0,5 %

compartment

Bay width 800 mm

Height, depth

Standards EN/IEC

see typical

bay arrange-

ments


18/18

Tel.: +49 180 / 524 70 00

Fax: +49 180 / 524 24 71

E-mail: [email protected]

www.siemens.com/ptd-support

(Subject to changee.g. 12 ct/min)

For further questions about our Power

Transmission and Distribution offers please contact

our Customer Support Center 24/7 at:

The information in this document contains generaldescriptions of the technical options available, whichdo not always have to be present in individual cases.The required features should therefore be specifiedin each individual case at the time of closing the

contract.

Siemens AG

Power Transmission

and Distribution

High Voltage DivisionPostfach 32 20

91050 Erlangen

Germany

www.siemens.com/ptd

Subject to change without prior notice

Order No. E50001-U113-A179-V2-7600

Printed in Germany

Dispo-Stelle 30000

61D7228 TV/EK100828 PA1003.

Further copies of this brochure

HIS Highly-integrated switchgear up to 145 kV

HIS Highly-integrated switchgear up to 550 kV

HIS CD-ROM for Windows 95/NT 4.0 or higherGas-insulated switchgear up to 245 kV

Gas-insulated switchgear up to 300 kV

Gas-insulated switchgear up to 550 kV

Container-type switchgear

Digital control and monitoring for high-voltage switching devices

Gas-insulated switchgear product range

For furtherInformation

Tel. +49 91 31/7-3 46 60

Fax +49 91 31/7-3 46 62

E-mail: [email protected]

www.hv-substations.com

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Street

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