Medium Voltage 110kv Potential Transformer for Substation

Product structure and function

The High voltage 66kv 110kv 220kv high capacitor voltage transformer (hereinafter referred to as CVT) is composed of a capacitor divider and an electromagnetic unit.

The two voltage of the electromagnetic unit is the same as that of the primary voltage added to the capacitor divider.The proportion is the same and the phase is the same.
Products are used to provide voltage signals for measuring instruments and meters. Provide voltage signals for relay protection and control devices.

Capacitive divider

The capacitor divider is composed of a high voltage capacitor (C1) and a medium voltage capacitor (C2). Located in porcelain bushing and filled with insulating oil.

Electromagnetic unit

The electromagnetic unit consists of an intermediate transformer, a compensation reactor, a damper and a safety device.
It is located in the fuel tank. The two winding terminals, CVD low end, grounding terminal and protection gap are located in the terminal box.

Oil seal

The capacitive elements of the capacitive divider are sealed in the porcelain sleeve, heated, vacuum-dried, and then injected with degassed, dehydrated insulating oil to keep the vacuum.
The flow rate change caused by the temperature change can be adjusted by the external metal expander located on the top of the porcelain sleeve to make the ceramic interior oil

The pressure is always maintained at the positive pressure of 0.0005-0.05kg/cm2.

The components of the electromagnetic unit are sealed in the box body and then heated, vacuum dried and injected with degassed, dehydrated insulation oil and sealed.

The oil change caused by temperature changes can be adjusted by the air layer at the top of the mailbox.

capacitive divide

• Light weight and small volume.
• The change of capacitance and voltage ratio caused by temperature change is very small.
• The metal expansion device is externally placed, and the inner part maintains a micro positive pressure and is not easy to leak oil.
• The inductance component of capacitor is small, which is propitious to line carrier communication.
• The loss angle tangent value is low, the partial discharge quantity is very small, the service life is long.
• Medium-low-pressure outlet using non-partial-discharge epoxy casting integrated casing and no leakage oil.
• The high-voltage end adopts corona-proof aluminum alloy cap cover and is favorable for high-voltage connection.

 Electromagnetic unit

• The parameters of the intermediate transformer, compensating reactor and damper are carefully designed to ensure that the CVT does not resonate at rated voltages of 0-1.5 or 0-1.9 times.
• The Central Asian part is completely isolated from the low pressure part to ensure that the electromagnetic unit's volume is less than 5PC.
• The terminal plate adopts epoxy casting structure and is equipped with wiring row for user connection, which effectively prevents oil leakage.
• The lightning arrester adopts the integrated structure of epoxy casting, which eliminates the disadvantages of oil immersion and damp of the lightning arrester.

Specifications