HIGH QUALITY EPOXY RESIN LV BUSHING

The transformer bushing is the main insulation device outside the transformer box, and the lead wire of the transformer winding must pass through the insulating sleeve to insulate the lead wire and between the lead wire and the transformer shell, and at the same time play the role of fixing the lead wire. Due to different voltage levels, insulating sleeves are in the form of pure porcelain sleeves, oil-filled sleeves and capacitor sleeves. Pure porcelain bushing is mostly used in 10kV and below transformers, it is in the porcelain sleeve to wear a conductive copper rod, porcelain sleeve for air insulation; oil-filled sleeve is mostly used in 35kV transformer, it is in the porcelain sleeve oil-filled, in the porcelain sleeve to wear a conductive copper rod, copper rod wrapped insulating paper; capacitive bushing is used in 100kV or more high-voltage transformer, by the main insulating capacitor core, the outer insulation upper and lower porcelain parts, connecting sleeve, oil pillow, spring assembly, base, equalizing ball, measuring terminal, terminal, rubber washer, insulating oil, etc.

INTRODUCTION:

The transformer bushing is an insulating sleeve that leads the high and low voltage leads inside the transformer to the outside of the fuel tank, not only as the lead wire is insulated to the ground, but also plays the role of fixed lead, the transformer bushing is one of the transformer current-carrying components, in the operation of the transformer, the load current is passed for a long time, and the short-circuit current occurs when the transformer is short-circuited outside. Therefore, the following requirements are placed on the transformer bushing:

(1) Must have the specified electrical strength and sufficient mechanical strength.

(2) It must have good thermal stability and be able to withstand instantaneous overheating in the event of a short circuit.

(3) Small appearance, small mass, good sealing performance, strong versatility and easy maintenance.

STRUCTURE:

The casing is mainly composed of a capacitor core, an oil pillow, a flange, and an upper and lower porcelain sleeve, and the main insulation is a capacitor core, which is made of concentric capacitors in series, and is enclosed in a sealed container composed of the upper and lower porcelain sleeves, oil pillows, flanges and bases, and the container is filled with treated transformer oil, so that the internal main insulation becomes an oil-paper structure. The contact surface between the main components of the casing is lined with oil-resistant rubber gaskets, and each component is fully sealed by the central compression force exerted by a group of strong springs arranged in the oil conservator. The flange is equipped with a vent plug, an oil extraction device, a device for measuring the dielectric loss of the casing (tan δ, referred to as dielectric loss) and partial discharge (referred to as partial discharge). During operation, the outer cover of the measuring device must be covered to ensure that the end screen is grounded, and it is strictly forbidden to open the circuit.

There are two ways to connect the bushing and the transformer high-voltage lead, which are cable threading and guide rod current-bearing.