Resistive Capacitive Voltage Dividers for Gas … RC Voltage...Resistive Capacitive Voltage Dividers for Gas Insulated Switchgear. ... Trench Resistive Capacitive Voltage Dividers

Resistive Capacitive Voltage Dividers for Gas Insulated Switchgear

IntroductionPower 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.

Both for power quality measurements and for measure-ments 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.

Harmonics measurements Unlike capacitive voltage transformers (accuracy on narrow frequency band only) and inductive voltage transformers (harmonic frequency resonances between winding induc-tances 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.

Fig. 1: Equivalent Circuit Diagram of an RC Voltage Divider

R13: Primary Resistance

R24: Secondary Resistance

F: Spark Gap

RB: Load Resistance

C11: Primary Capacitance

C22: Secondary Capacitance

Ck: Stray Capacitance

CB Burden Capacitance

Fig. 2: Magnitude versus frequency test over the entire bandwidth

Fig. 3: Bandwidth comparison of an Inductive Voltage Transformer, a CVT and an RCVD

4

3

2

1

0

-1

-2

-3

-41 10 100 1.000 10.000 100.000 1.000.000

Frequency [Hz]

Ratio

Err

or [%

]

500

400

300

200

100

00 500 1000 1500 2000 2500

Ratio

Err

or [%

]

Frequency [Hz]

Capacitive Voltage Transformer 420 kV

RC Voltage Divider 420 kV

Inductive Voltage Transformer 420 kV

High Voltage Terminal

Coaxial Cable

Ground Terminal

RC Voltage Divider

External BurdenR13

R24

C11

C22 CkRk CBF

1a

1n

2

DesignTrench 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 resis-tance 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

• Availableforvoltagelevels72.5kV–145kV (three-phasedesign)and245kV–550kV (single-phase design)

• AccuratefromDCupto20kHz

• Bandwidthupto2MHz

• Ferroresonance-free(nosaturablecores)

• Excellenttransientcharacteristics

• Conformtomicroprocessor-basedsecondarytechnology

• Short-circuitproofdesign

• Disconnectionduringcommissioningtestsonsite not necessary, e.g. in case of DC-tests (cable tests)

• Significantsizeandweightreduction

Fig. 4: RCVD 145T Fig. 5: RCVD 420

3

3-Phase Units

TypeRCVD 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 1.5 or 1.9

Accuracy range [kHz] 0–20

Rated burden 1 MΩ + 500 pF

Metering classaccording 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

RCVD 145T

Technical Data

4

1) Design RCVD 300 – 420 2) Design RCVD 420 – 550

Single-Phase Units

TypeRCVD 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 1.5 or 1.9

Accuracy range [kHz] 0–20

Rated burden 1 MΩ + 500 pF

Metering classaccording to IEC or ANSI

Protection class

Temperature range [°C] -30–+55

Insulation class E

Weight [kg] 110 160 1601601)

2602602)

Height [mm] 1257 1852 185218521)

152215222)

Min. phase distance [mm] 400 490 4904901)

6466462)

RCVD 245 RCVD 300 – 420 RCVD 420 – 550

5

Trench Factories

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 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 CEP32370-485 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 France S.A. 16, Rue du Général Cassagnou B.P.70F-68302 St. Louis, Cedex France Phone:+33-3-89-70-2323 Fax:+33-3-89-67-2663

Trench Germany GmbH Nürnberger Strasse 199 D-96050 Bamberg Germany Phone: +49-951-1803-0 Fax: +49-951-1803-224

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. StradaCuragnata,37 IT-17014Bragno Cairo, Montenotte (SV) Italy Phone; +39-019-5161-111 Fax: +39-019-5161-401

Trench Limited Bushing Division 432 Monarch Avenue Ajax, Ontario CanadaL1S2G7 Phone: +1-905-426-2665 Fax:+1-905-426-2671

Trench Limited Coil Products Division 71MaybrookDrive Scarborough, Ontario Canada M1V 4B6 Phone: +1-416-298-8108 Fax: +1-416-298-2209

Trench Limited Instrument Transformer Division 390 Midwest Road Scarborough, Ontario Canada M1P 3B5 Phone:+1-416-751-8570 Fax:+1-416-751-6952

Trench Limited Power Line Carrier Division 330 Finchdene Square Scarborough, Ontario Canada M1X 1A5 Phone:+1-416-847-5400 Fax: +1-416-291-5581