Capacitive voltage transformer
Capacitive voltage transformers can be used for voltage and power measurement, relay protection, automatic control, and other aspects in high-voltage and ultra-high voltage power systems, and can also serve as coupling capacitors for power line carrier communication systems. If required, internal accessories and external wiring terminals for harmonic voltage measurement can be provided.
Environmental requirements for use
Installation and operation site: outdoor type
Altitude: Generally not exceeding 2000 meters, plateau products up to 4000 meters can also be provided according to order requirements.
Environmental temperature: divided into -25~+45 ℃ and -40~+40 ℃, selected by the user when ordering.
Wind speed: not exceeding 42m/s.
Pollution level:
Level III pollution (external insulation creepage distance ≥ 25mm/kV);
Level IV pollution (external insulation creepage distance ≥ 31mm/kV). The pollution level is chosen by the customer at the time of ordering.
Re icing thickness: not exceeding 10mm.
Earthquake intensity: not exceeding 8 degrees. According to user requirements, products with higher seismic resistance can also be provided.
System rated frequency: 50Hz or 60Hz. To be determined by the user at the time of ordering.
System grounding conditions: The neutral point is effectively grounded or the neutral point is not effectively grounded, which is determined by the user at the time of ordering.
Main technical performance
★ Allow long-term operation at any voltage below 1.2 times the rated voltage. The CVT for the neutral point effective earthing system can operate for 30s at 1.5 times the rated voltage, and the CVT for the neutral point ineffective earthing system (with tail note F in the model) can operate for 8h at 1.9 times the rated voltage.
The allowable deviation of the capacitance of the capacitive voltage divider is+10%~-5% of the rated value.
★ The dielectric loss angle tangent value (20 ℃) of the capacitive voltage divider shall not be greater than 0.001, and the partial discharge amount shall not be greater than 10pc.
★ Creepage distance: The minimum creepage distance is 25mm/kV~31mm/kV, which is selected by the user when ordering.
The phase relationship between the primary and secondary voltages of CVT is polarity reduction, and the connection method of each winding of the medium voltage transformer is as follows:
Secondary two winding 1/1/1-12-12
Secondary three winding 1/1/1/1-12-12-12
Secondary four winding 1/1/1/1/1-12-12-12
Radio interference level (RIV) of 330~500kVCVT ≤ 500 υ V。 The RIV of products below 200kV is less than 350 υ V。

CAPACITOR VOLTAGE TRANSFORMER 

MAIN DESIGN FEATURS AND ADVANTAGES 
High electric strength. Wide insulation margin 
High-quality medium and new structure design application and advanced technology, the electric strength of CVT is improved obviously, guarantee the product operation reliability effectively 
Long creepage distance. Strong pollution resistance 
The capacitor insulator which the company used has actually long creepage distance, the dry arcing distance is the longest of all, the results of creepage distance/ dry arcing distance is rational. It improves the margin of the outer insulation resistance effectively, enhance fouling resistance. 
High accuracy of product. Wide margin 
The 11 OkV~ 765kV products can meet the accuracy ofO.l requirements, through the accuracy of characteristic test. Meanwhile the accuracy adjustment tenninal can be lead to outside of product, and adjust the accuracy terminal according to actual needs at location. 
High mechanical strength 
High mechanical strength capacitor insulator and optimized structure design, it improves product mechanical strength. In the earthquake of Wenchuan, 500kV CVT has operationed at hydropower plant YuZiPingpu which withstood the test. 
Good transient response 
Damping optimu design, the CVT transient response to 3PTI level, the residual voltage is less than 2%. Can better adapt to requiremeots of fast relay. 
Small dielectric loss products. Good PD performance 
Reasonable structure of the media and design, advanced technology which can make the dielectric loss (tan 6) reduced to below 0.08%, making the PD performance reduced to below SpC 
Good sealability, ensure no leakage 
Good seals and optimization structure, second terminal board using lead with SMC overall vacuum pouring parts, which can ensure do not produce oil leakage phenomenon. 
ENVIRONMENTAL CONDITIONS 
Capacitor voltage transformer (CVT) is widely used in power system 35 kV~ l000kV. Which mainly used for measuring voltage, power and energy metering, simultaneously to the relay protection device and automatic control device provide voltage signal. Which also be used to power line carrier-current collllllunication coupling capacitors and can also be used for the monitoring of the harmonic wave in the power grid voltage. 
Structure: single phase, single pillar 
Location: indoor or outdoor 
Ambient temperature : -40°C~+45°C(Freezing field can meet- 50 "C) 
Wind load: not exceed 42m/s 
Altitude: not exceed 2000m 
Icing thickness: not exceed 10mm 
Seismic strength: 8 
Pollution level:III or IV 
Note: According to user needs, we can provide to meet other special using conditions of the capacitor voltage transformers. 

DEMONSTRATION OF TIIE TYPE 
TYD -1-2-3
In: 
TYD----Capacitor voltage transformer 
1—Ratedvoltage, kV 
2——Ratedcapacitance, µ F 
3－Endnote,features code 
In the Endnote· 

H-esistance to pollution type products

G-Used for plateau products(Altitude above 2000m areas)

F-Using non-soildly earthed neutral systems 

For example: type TYD66/ ✓3 -0.02FH means that this CVT using non-soildly earthed neutral systems 66kV, the capacitance of Capacitor divider is 0.02 µ F, can be used for pollution level III area.