Feasibility of a common, dry type
interface for GIS and power
cables of 52kV and above
26 March 2012
Rationale
The interface between High Voltage cable and switchgear is defined by IEC 62271-209
and IEEE 1300.
They define two types of the dry-type cable connections for gas insulated switchgear
above 52 kV. The limit of supply of the cable termination manufacturer is the insulator.
In Medium Voltage, EN 50181, describes “Plug-in type bushings above 1 kV up to 36
kV for equipment other than liquid filled transformers”. The insulator has standardised
dimensions on the cable side, such that a separable connector can be plugged in on the
cable side. The separable connector can then be supplied by one of several possible
suppliers.
With the above background a number of customers expressed interest in extending the
principle of a common insulator interface to higher voltages with the potential benefits
that cable connections from different manufacturers would be interchangeable in a
single insulator.
This is the reason why the CIGRE JWG B1-B3 33 was formed with the following TOR
Feasibility of a common, dry type interface for GIS and power cables of
52kV and above
The scope shall be limited to GIS connections for extruded cable systems for AC above 52 kV
The JWG shall:
Examine the conditions around the switchgear and the installations issues, including supporting
system (also called site issues)
Consider the impact of large cross sections
Consider safety during works
Consider the testing procedures for GIS/ Terminations and cables at factory and on site
(overlapping or missing items).
Propose measures to reduce the potential consequences of the GIS insulation failure.
Propose measures to reduce the potential consequences of the cable termination insulation failure
Review the existing standards ruling the qualifications and extension of qualification procedures
applicable to GIS terminations.
Define the relevant qualification procedures needed if any.
Identify the limit of suppliers’ responsibility to be consideredEstimate the overall technical and
practical feasibility of the common design definition and qualification, insulator
manufacturers' qualification and the cable manufacturers' qualification and the cost involved.
Feasibility of a common, dry type interface for GIS and power cables of
52kV and above
Once the feasibility window has been determined, survey the market (manufacturers and end
users)
Recommend or not to go to a second step with the launching of a new WG B1.XX to go in detail
in the design of the standard components (shape, dimensions, properties ...)
Develop recommendations to IEC SC 17C for requirements to be covered by the standard
The full report shall be made available for final review at the B1 and B3 annual meetings in 2013.
Pierre Argaut
Pierre Mirebeau
Regular members
• B1 (cables)
Giuseppe Nicoli
Johannes Kaumanns
Milan Uzelac
Franck Michon
Pascal Streit
Josu Orella
Julian Head
Henk Geene
John Schrijnemakers
(B1 chairman)
(B1-B3.33 convenor)
Nexans
Prysmian
Sudkabel
G&W Electric
Prysmian
(B1-B3.33 secretary)
Nexans
Iberdrola
Prysmian
Prysmian
Tennet (new member)
DongYun Oh
(IT)
(DE)
(USA)
(FR)
(CH)
(SP)
(UK)
(NL)
(DK)
(KR)
B3 (substations)
Mohammad Pasha
Mark Kuschel
Guilhem Blanchet
Markus Keller
(USA)
(DE)
(FR)
(CH)
United Illuminating
Siemens
Alstom Grid
ABB
Addition
Thomas Klein
Dirk Kunze
(DE)
(DE)
Pfisterer
Siemens
LS Cable & System
•
•
Corresponding members B1
Christian Szczepanski (BE)
Elia Engineering (new member)
Members
Meetings
Meetings up to date Nov. 10th 2010 Kick
Paris
Jan. 27th 2011
June 24th 2011
Nov. 15-16th 2011
March. 22- 23 2012 Shelton
Delft
Versailles
Berlin
Next meeting(s):
Paris
August 2012
Table of content
1. Introduction and scope
2. Definitions
3. Experience :
a. Different designs available
b. Actual installations including dimensions
c. Field experience with all designs.
4. Where the plug in concept could be applicable.
a. Geometrical constraints.
5. Qualification and others
a. Technical requirements
i. Cable side
ii. GIS side
b. Survey of standards – qualifications requirements
i. Cable side
ii. GIS side
6. Where the plug in common interface is applicable
7. Other requirements
8. feasibility
a. Definition feasibility (cost involved)
b. Qualification feasibility
9. Market acceptance
10. Where the plug in common interface could be recommended
a. Benefit and drawback
b. Range to cover
c. Implication in standard
11. Conclusion
The idea of this organisation
is to start from the actual
object in the field, and
have a first conclusion,
then look to
"administrative" aspect,
and draw a refined
conclusion, then include
the feasibility and market
acceptance aspect, and go
to a recommendation.
Plug-In Types
InnerCone
Plug-In
Type
Differences in design of barrier insulator
• Main circuit end terminal
Interfaces GIS connector and houses
male plug-in connector
– May be incorporated in top insert or
be separate component
– Bore is designed for particular plugin connector
• Plug-in connector
Connects cable connector with end
terminal
– There are different types:
• Spring
• Tulip
• Multicontact
– May be fixed to either end terminal
or to cable connector
Differences in design of barrier insulator
IEC
Dimension
• This dimension varies
between manufacturers
• HV screen
Embedded in the insulator.
Shapes electrical field and, in
some designs, provides
mechanical stop for stress cone
or/and cable connector
– The design differs between
manufacturers
– Made of metal or epoxy with
conductive coating
Differences in design of barrier insulator
• Barrier Insulator
– Material and fillers varies
– Creepage distance varies
– Bore shape and size depends on the
stress cone
• With or without ground screen
Shapes electrical field at ground
electrode
– Shape depends on overall electrical
design of the device
• Bottom inserts
– Number, size, strength and material
• Insulation shield break ring
– Shape and size varies
– Sometimes not integrated in the
insulator
• Bottom surface finish
– As a function of requirements
(watertightness)
Requirements for
standardisation of a common
interface
• Under discussion in the JWG
type of installation a
type of installation b
Solution 1a
Solution 1b
Solution 2a
Solution 2b
Geometrical
constraints
case 1
case 2
We consider
case 1a
Geometrical
constraints
•
•
•
•
D: cable diameter
H bas.: minimum basement height = 20D + D
L bas.: minimum free cable length in basement according to H bas. allowing a maximum
vertical snaking
Ls: available length due to cable snaking
Geometrical constraints
Summary table ( rounded v alues), bas ed on c ommon c ables w ith a screen made of
aluminium foil bonded to the outer sheath:
Cable type
D (mm)
Weight (kg/m)
H bas. (m)
L bas. (m)
Ls (m)
Weight of cable to move
(kg)
Cable 1
630 Al
63kV
65
4.5
1.36
5.9
0.93
Cable 2
630 Cu
110kV
80
9.6
1.68
7.3
1.14
Cable 3
1000 Cu
220 kV
100
17
2.10
9.1
1.43
Cable 4
1600 Cu
220 kV
120
23
2.52
10.9
1.71
Cable 5
2500 Cu
500 kV
150
40
3.15
13.6
2.14
33
86
190
310
680
Under discussion impact of the cable stiffness
and the installation temperature
Conclusion
• The group behaviour is fully satisfactory.
• There is a good balance between manufacturers and users.
• Considering the above, we feel that we will complete the work on time