Station Sevrice Voltage Transformers，SSVT / Power Voltage Transformers, PVT / Auxiliary service voltage transformer, Gas insulation type, SSVT 72.5~550kV

Voltage transformerare designed in accordance with IEC61869-3, ANSI/IEEE C57.13, CAN/CSA C60044-2.

Standards

Voltage transformerare designed in accordance with IEC61869-3, ANSI/IEEE C57.13, CAN/CSA C60044-2.

Power transformer are desinged in accordance with IEC 60076, ANSI/IEEE C57.12

IEEE IEC P63253-5713-8 Station service voltage transformers

Description

The Stationservice voltage transformeris a voltage transformerinsulated in SF6 gas that combines the characteristics of a voltagetransformer with power transformation capability.The SSVT has been designed for voltage up to 550 kV and with powercapability up to 333kVA. SSVT converts the optimum power directly from high voltage side to medium/low voltage side.

The SSVT feature rugged transformer designs incorporating high creepage composite insulators and high over-voltage capability with impedance protection to limit fault currents. The SSVT is a line-to-ground connected single-phase transformer that can be used either as an individual unit for supplying single-phase loads, or in a three-phase bank to support larger kVA three-phase loads.

There is a pressure relief device at the top of the power transformer, when the pressure is more than 0.8MPa(1.0 MPa only for 500kV) if the power transformer is discharge inside, the relief device will be broken to release the pressure and send an alarm information.

There is a SF₆density monitor fix at the base, it can indicate the SF₆pressure which inside the power transformer (its indicated value is the SF₆pressure at 20℃), and it will provide an information when the SF₆pressure is drop down to the minimum service pressure of the power transformer, to remind the user replenish the SF₆gas to the rated pressure.

Main Technical Characteristics

• Highest system voltage: 72.5~550kV

• Rated frequency: 50Hz or 60 Hz

• Output voltage: 115V, 120V, 220V, 380V,400V,10kV, 13.8kVor according to the requirements of the clients.

• Rated power: 25, 50, 75, 100, 125 and 333 kVA or according to the requirements of the clients

• Partial discharge level: <10pC

• Metering accuracy class IEC: 0.2, 0.5, 1.0

• Metering accuracy class IEEE: 0.3, 0.6, 1.2

• Protection accuracy class: 3P, 6P

• Rated voltage factor: 1.2 continue, 1.5/30s

• Rated operating pressure of gas SF6 is 0.40MPa (0.50 MPa only for 500 kV)

• Minimun operating pressure of the gas SF6 is 0.35MPa (0.45 MPa only for 500 kV).

• Annual leakage: ≤ 0.1% at the rated pressure of SF₆

• SF6 moisture content:≤100×10-6(V/V)

• Temperature rise limit: ≤60K

• Ambient temperature: -50℃ to +50℃

• Creepage distance: 25mm or 31mm/Kv

• Earthquake standard design: up to 0.5g

Basic insulationlevel

Outline Drawing & Dimensions

SANDINA 245kV SSVT, Power burden: 333kVA, Operating at substation of Ecuador(Siemens EPC substation project).