1500kVA 22/0.4kV transformer oil tank manufacturing

The 1500kVA-22/0.4kV distribution transformer is in production and is ready to be delivered to South Africa. Below is the oil tank of this transformer.

1. Fuel tank function:

The oil tank is the outer shell of the transformer, which houses the core and windings and is filled with transformer oil so that the core and windings are immersed in the oil. Transformer oil insulates and dissipates heat. Large transformers generally have two oil tanks, one is the main oil tank; the other is the on-load voltage regulating box, with a tap changer installed in the on-load voltage regulating box. This is because arcing occurs during tap changer operation. If operated frequently, the insulating properties of the oil will be reduced. Therefore, set up a separate tank and place the tap changer separately;;;

2. Fuel tank classification:

Common transformer oil tanks have three basic types according to their capacity: box-type oil tanks, bell-type oil tanks and sealed oil tanks.

3. Requirements for fuel tanks

(1) The transformer oil tank should be welded with high-strength steel plates. Anti-magnetic shielding measures should be taken inside the oil tank to reduce stray losses. The magnetic shield should be secured and insulated to avoid overheating or discharge due to poor contact. Various shields should have good conductivity and reliable grounding to avoid floating discharge or affecting the dielectric loss coefficient value of the winding.

The top of the tank should be provided with a slope so that the gas can be discharged and collected to the gas relay. All openings on the top of the tank should have raised flanges. The vent plug should be set at the highest point wherever air can be trapped and connected to a common pipe to collect the gas to the gas relay. Install a gas collecting pipe on the riser of the high and medium pressure casing and connect it to the connecting pipe between the oil tank and the gas relay. The slope of the pipe leading to the gas relay should be 1.5%. The gas relay should be protected from rain, and the gas collecting pipe should be led to the ground. The channel steel structure base should be set outside the bottom plate of the transformer tank so that the transformer can be dragged along its long and short axes. The base should be equipped with necessary towing devices. The base should also be equipped with means that can be anchored to the concrete foundation with anchor bolts. Anchor bolts should be sufficient to withstand the inertial force of the equipment's own weight and the displacement caused by seismic forces. The manufacturer shall submit the bolts and fixing methods to the operating unit for approval.

The fuel tank should be assembled in two parts. If the joint is welded securely, flanges and gaskets that can be welded repeatedly must be used.

(2) Two oil supply tank grounding terminals should be set at the two diagonal lines at the bottom of the tank (the transformer tank, that is, the shell is grounded, mainly to ensure personal safety. When the insulation of the transformer is damaged, the transformer shell will be charged. If grounding measures are taken, the leakage current of the transformer will be guided to the earth through the shell grounding device, thereby preventing personal electric shock.

Grounding requirements for the transformer tank shell and grounding device: ① The grounding body and grounding wire should be welded firmly. ②The grounding resistance should not be greater than 0.5 Ω, and the grounding wire should be reliably connected to the equipment. ③The diameter of the round steel grounding body should comply with relevant regulations.

(3) The transformer oil tank should be equipped with the following valves: ① Transformer main oil tank oil drain valve and oil reservoir; ② Oil sample valve (the internal thread of the oil sample valve is greater than 8mm and equipped with a removable plug); ③ Oil filter, isolation, Vacuuming, oil filling, emergency oil drain valve, etc.