Resistive Capacitive Voltage Dividers
for Gas Insulated Switchgear
Introduction
Power quality has become a major concern, both for
electricity providers and their customers. As today’s
electrical equipment is far more sensitive than electrical
devices of the past, a reliable picture of the HV line
voltage is needed to determine the origin of power
disturbances.
RC Voltage Divider
High Voltage Terminal
R13
Harmonics measurements
Unlike capacitive voltage transformers (accuracy on narrow
frequency band only) and inductive voltage transformers
(harmonic frequency resonances between winding inductances and stray capacitances), RC Voltage Dividers are
linear from DC up to 20 kHz. Harmonics can be measured
with an accuracy better than 1 % (see Fig. 2) and a phase
displacement less than 1° on this frequency range.
Ratio Error [%]
Both for power quality measurements and for measurements at rated frequency, Trench Resistive Capacitive
Voltage Dividers (RC Voltage Dividers) are able to
measure over a large frequency band with a high
accuracy. They are an effective solution for a modern
SMART Grid infrastructure.
Measurements at rated frequency
Trench RC Voltage Dividers cover all IEC and ANSI metering
requirements (class 0.2 or lower). They can also be used for
protection purposes according IEC or ANSI.
C11
1
-2
1a
F
2
-1
-3
1n
C22
3
0
External Burden
Coaxial Cable
R24
4
Ck
Rk
Ground Terminal
-4
CB
1
10
100
10.000
1.000
100.000
1.000.000
Frequency [Hz]
Fig. 2: Magnitude versus frequency test
over the entire bandwidth
R13: Primary Resistance
R24: Secondary Resistance
F: Spark Gap
RB:
Load Resistance
C11: Primary Capacitance
C22: Secondary Capacitance
Ck:
Stray Capacitance
C B
Burden Capacitance
Ratio Error [%]
Fig. 1: Equivalent Circuit Diagram of an RC Voltage Divider
500
400
Capacitive Voltage
Transformer 420 kV
300
200
Inductive Voltage
Transformer 420 kV
RC Voltage
Divider 420 kV
100
0
0
500
1000
1500
2000
2500
Frequency [Hz]
Fig. 3: Bandwidth comparison of an Inductive Voltage
Transformer, a CVT and an RCVD
2
Fig. 4: RCVD 145T
Fig. 5: RCVD 420
Design
Trench RC Voltage Dividers are designed based on the
long experience with capacitive dividers and capacitors
for different applications (capacitive voltage transformers,
coupling capacitors, dividers for DC applications or test
labs, energy storage capacitors or grading capacitors).
The resistors connected in parallel to the capacitor
windings are designed to guarantee an extremely low resistance variation through time, electrical stress and
temperature.
The insulation system is made of oil / paper-polypropylene
mounted in a composite housing. The whole design is
directly mounted into the GIS in the common SF6-gas
compartment.
Trench RC Voltage Dividers are designed to allow an easy
and fast customization to specific customer requirements.
Features
• Available for voltage levels 72.5 kV – 145 kV
(three-phase design) and 245 kV – 550 kV
(single-phase design)
• Accurate from DC up to 20 kHz
• Bandwidth up to 2 MHz
• Ferroresonance-free (no saturable cores)
• Excellent transient characteristics
• Conform to microprocessor-based secondary technology
• Short-circuit proof design
• Disconnection during commissioning tests on site
not necessary, e.g. in case of DC-tests (cable tests)
• Significant size and weight reduction
3
Technical Data
RCVD 145T
3-Phase Units
Type
RCVD
72T
RCVD
123T
RCVD
145T
Um
[kV]
72.5
123
145
AC
[kV]
140
230
275
BIL
[kV]
325
550
650
SIL
[kV]
-
-
-
Output voltage
[V]
As required (typically 100/√3)
Rated voltage factor
Accuracy range
1.5 or 1.9
[kHz]
0 – 20
Rated burden
1 MΩ + 500 pF
Metering class
according to IEC or ANSI
Protection class
Temperature range
[°C]
-30 – +55
Insulation class
E
Weight
[kg]
90
90
90
Height
[mm]
770
770
770
Min. field distance
[mm]
575
575
575
4
RCVD 245
RCVD 300 – 420
RCVD 420 – 550
Single-Phase Units
Type
RCVD
245
RCVD
300
RCVD
362
RCVD
420
RCVD
550
Um
[kV]
245
300
362
420
550
AC
[kV]
460
460
510
630
680
BIL
[kV]
1050
1050
1175
1425
1550
SIL
[kV]
-
850
950
1050
1175
Output voltage
[V]
As required (typically 100/√3)
Rated voltage factor
Accuracy range
1.5 or 1.9
[kHz]
0 – 20
Rated burden
1 MΩ + 500 pF
Metering class
according to IEC or ANSI
Protection class
Temperature range
[°C]
-30 – +55
Insulation class
E
Weight
[kg]
110
160
160
Height
[mm]
1257
1852
1852
Min. phase distance
[mm]
400
490
490
1601)
2602)
18521)
15222)
4901)
6462)
1)
2)
260
1522
646
Design RCVD 300 – 420
Design RCVD 420 – 550
5
Trench Factories
Trench Austria GmbH
Paschinger Strasse 49
Postfach 13
A-4060 Linz-Leonding
Austria
Phone: +43-732-6793-0
Fax: +43-732-671341
Trench Brasil Ltda
Via Expressa de Contagem, 2685
Contagem, Minas Gerais
CEP 32370-485
Brazil
Phone: +55-31-3391-5959
Fax: +55-31-3391-1828
Trench China
MWB (Shanghai) Co., Ltd.
No. 3658, Jiancheng Road
Minhang, Shanghai
P. R. China
200245
Phone: +86-21-54720088
Fax: +86-21-54723118
Trench High Voltage Products Ltd.,
Shenyang
No. 2 Zhengliang Er. Road
Jing Shen Xi San Street
Dao Yi Economic Development Zone
Shenyang 110136 P. R. China
Phone: +86-24-89722688
Fax: +86-24-289737200
Trench Italia S.r.l.
Strada Curagnata, 37
IT-17014 Bragno
Cairo, Montenotte (SV)
Italy
Phone; +39-019-5161-111
Fax: +39-019-5161-401
Trench Limited
Bushing Division
432 Monarch Avenue
Ajax, Ontario
Canada L1S 2G7
Phone: +1-905-426-2665
Fax: +1-905-426-2671
Trench France S.A.
16, Rue du Général Cassagnou
B.P. 70 F-68 302
St. Louis, Cedex
France
Phone : +33-3-89-70-2323
Fax : +33-3-89-67-2663
Trench Limited
Coil Products Division
71 Maybrook Drive
Scarborough, Ontario
Canada M1V 4B6
Phone: +1-416-298-8108
Fax: +1-416-298-2209
Trench Germany GmbH
Nürnberger Strasse 199
D-96050 Bamberg
Germany
Phone: +49-951-1803-0
Fax: +49-951-1803-224
Trench Limited
Instrument Transformer Division
390 Midwest Road
Scarborough, Ontario
Canada M1P 3B5
Phone: +1-416-751-8570
Fax: +1-416-751-6952
The Trench Group is your partner of choice for electrical
power transmission and distribution solutions today and
for the development of your new technology solutions
of tomorrow.
Trench Limited
Power Line Carrier Division
330 Finchdene Square
Scarborough, Ontario
Canada M1X 1A5
Phone: +1-416-847-5400
Fax: +1-416-291-5581