compact switchgear: a practical guide to it’s use in a ... · fully interlocked with sliding star...
TRANSCRIPT
COMPACT SWITCHGEAR: A practical guide to it’s
use in a Distribution Network
23 March 2018
PRESENTED BY: Struan Steele
General Manager ACTOM Energy Namibia
MV GIS RMV RING MAIN UNIT
Designed, constructed and tested in accordance with:
• SANS 1874 / NRS 006 (Ed. 3, 2015)
• SANS 876 / NRS 012 (Ed. 2, 2009)
• IEC 62271-200 (Ed. 2, 2011)
– IEC 62271-100
– IEC 62271-102
– IEC 62271-103
– IEC 62271-105
IEC / NRS / SANS standard compliance
MV GIS RMV – ratings
Rated Voltage 12 kV / 24 kV
Rated normal current 630 A
Rated short-circuit current20 kA, 3 sec (3-ph main circuit & earthing devices)
20 kA, 1 sec (1-ph earthing circuit – phase-earth)
Rated power frequency withstand voltage 28 kV / 50 kV
Rated lightning impulse withstand voltage 95 kV / 125 kV
Service continuity LSC2
Partition class PM (Metallic Partitions)
Internal arc classification (IAC)
AFLR 20 kA 0,5 sec (indoor – with arc duct)
AB 20 kA 0,5 sec (outdoor – with kiosk)
AFL 21 kA 1 sec (RMU gas tank)
Cable test facility withstand voltage 25 kV AC, 38 kV DC (SANS 10198-13)
Ambient temperature - 25 OC to + 40 OC
SF6 gas pressure (at 20 OC)rated: 0.0345 MPa
minimum: 0.0138 MPa
MV GIS RMV – technical information
Circuit-breaker class S1, E2, M1, C2 (IEC 62271-100)
Switch-disconnector class E3, M1, C2 (IEC 62271-103)
Cable earthing switch class E2, M0 (IEC 62271-102)
Circuit-breaker interrupting technology Vacuum interrupter
Circuit-breaker mechanism Stored energy operation (spring mechanism)
Switch-disconnector & earthing switch
mechanismIndependent manual or power operation (3-position)
SF6 gas monitoring – gas density indicator
‘WIKA’ temperature-compensated, hermetically sealed (no
influence of temperature fluctuations, differences in altitude and
atmospheric pressure fluctuations)
Cable connection interface 630 A Type C (EN 50181 outside cone profile)
Integral cable test facilities
Fully interlocked with sliding star point connections (20 kA, 3
sec) - no bolted connections or removable copper bars (to
latest SANS 1874 standard)
Safety interlocks Mechanical interlocks (IEC 62271-200 & SANS 1874)
Cable live indication Voltage Detection System – VDS (IEC 61243-5)
MV GIS RMV Functions
‘L’ Function ‘C’ Function ‘F’ Function
Cable Riser Circuit Breaker Fused
WHAT WE WILL DISCUSS
• Overview of what Compact Switchgear is and where
it fits into a network
• What it was designed to do.
• Advantages and disadvantages
• Size
• Price
• Ease of operation
• Maintenance free
• Operator safety
• Cable Compartments and CT’s
• Terminations
• Cable Test Facility and SANS 0198
• Metering
• Protection Relays
• SUMMARY
WHAT IS COMPACT SWITCHGEAR ?
▪ Range of compact, maintenance
free secondary switchgear
▪ All live parts enclosed in a ‘sealed
for life’ tank
▪ Insulation is usually SF6 Gas or dry
air and cast resin
▪ Live parts in a sealed for life tank
insulated with either SF6 gas or
resin and dry air.
▪ Usually available in two ranges,
extensible and non-extensible
WHERE DOES IT FIT INTO THE NETWORK?
WHAT IS THIS EQUIPMENT DESIGNED TO DO?
• Replacement for old
oil insulated
switchgear,
particularly RMU’s
• Fits into the
secondary
distribution network
connecting to
primary switchgear
ADVANTAGES and DISADVANTAGES: SIZE
• Small and compact
• Front access and non-
withdrawable so minimal space
required around it
• Fits into kiosks for outdoor use,
mobile substations and minisubs
ADVANTAGES
DISADVANTAGES
• Very little space for extra relays
• Cable boxes are small
ADVANTAGES and DISADVANTAGES
• PRICE
• STANDARDISATION
• EASE OF OPERATION
• MAINTENANCE FREE
• FUTURE EXTENSIONS?
• FITS NICELY INTO A
KIOSK FOR OUTDOOR
APPLICATIONS
ADVANTAGES and DISADVANTAGES
OPERATOR SAFETY
RUPTURE PLATE
E
X
P
L
O
S
I
O
N
V
E
N
T
• IEC 62271-200 Ratings for Arc Venting
• Always safe to operate from the front
• Arc rating on Cable compartment covers
• Testing of Cable Test Facility
• Rotary switches on most types of equipment
ENVIRONMENTAL ISSUES
• SF6 Gas or dry air
• Manufacturer end of life return policy
• Vacuum in SF6 Gas
• All other material can be recycled
CABLE COMPARTMENTS AND CT’s
DESIGNED FOR SINGLE CORE XLPE CABLE
CABLE COMPARTMENTS AND CT’s
CABLE COMPARTMENTS AND CT’s
PILC CABLE XLPE CABLE
CABLE COMPARTMENT AND CT’s
PIGGYBACK TERMINATIONS
USING A SEPARABLE TEE BOOT
CABLE COMPARTMENT AND CT’s
CURRENT TRANSFORMERS
A PEDESTAL REQUIRED SOLKOR CT’s
CABLE TEST FACILITIES
RMU Functional Unit Equipment features
Switch-disconnector “L” function
• Designed and tested to comply with SANS 10198-13 Ed 2
(2015) Table 1 on-site cable test voltages (AC and DC)
• Tested in accordance with IEC 62271-200 clause 6.2.101
• Busbars energised at 24 kV AC when test voltages are
applied to each test bushing – as per on-site conditions
• AC: 25 kV (r.m.s.) (180° out of phase to busbar voltage)
• DC/VLF: 38 kV (15 minutes)
• Fully interlocked with cable earthing switch
• Extension probes supplied with each RMU (optional use)
METERING
DESIGNED FOR BUSBAR METERING
CABLE METERING IS POSSIBLE
BUT NOT A GOOD IDEA
• MOUNTING OF METER
• VOLTAGE TRANSFORMERS
PROTECTION RELAYS
WIC 1 CT POWERED RELAY
ADD ON PROTECTION CUBICLES
• overcurrent self powered protection relay
• short-circuit instantaneous (50) (I>>)
• overload (51) (I>)
– IEC & ANSI SI / VI / NI / LI IDMT curves
• earth fault (51N) (IE)
– definite time delay
• event recording (last trip event)
– faulted phase, fault current, type of fault
• PC manager (laptop link)
PROTECTION RELAYS
SUMMARY
• Where do you draw the line which is very blurred
• Keep it simple especially protection choices
• Not designed to replace primary switchgear
MV GIS COMPACT SWITCHGEAR – Any
Questions?
THANK YOU ACTOM Energy Namibia
Struan Steele 061 423 150
Actom Medium Voltage
Marius Van Meygaarden +27 83 270 0909