Transformer Oil Conservator: Mga Tipo Struktura ug mga Pungto Explained

Pamahalaan sa Transformer Oil Conservator

Ang oil conservator usa ka kritikal nga device sa pag-store sa langis alang sa mga transformer. Kon ang load sa transformer madaghan ug ang temperatura sa langis madaghan, ang insulating oil sa loob sa tank mag-eksapanda tungod sa init, kasagaran ang sobrang langis moadto sa conservator. Kini usab adunay epekto kon ang temperatura mobaba, ang langis sa conservator mobalik sa tank. Kini nga proseso makapahimo og automatic nga regulation sa level sa langis, naghatag sa conservator og duha ka function nga storage ug replenishment, siguradohon nga ang tank naka-fill ngadto sa full capacity.

Sa parehas nga panahon, ang conservator mobawas sa contact area sa pagitan sa langis sa transformer ug hangin. Ang moisture, dust, ug oxidized oil sludge nga gipangita gikan sa hangin moguho sa sediment trap sa ilalom sa conservator, siguradohon nga mobawasan ang degradation sa langis sa transformer.

Struktura sa Oil Conservator

Ang lawas sa conservator usa ka cylindrical container gihimo gikan sa welded steel plates, may volume na mahitungod 10% sa total nga capacity sa tank. Gi-mount siya horizontal sa itaas sa tank ug giconnect sa main tank pinaagi sa pipeline pinaagi sa gas relay, naghatag og espasyo para ma-free rise ug fall ang level sa langis sukad sa temperature changes. Sa normal nga operasyon, ang minimum nga level sa langis sa conservator dapat mas taas sa riser sa high-voltage bushing; para sa mga bushing nga gipakighubad, ang minimum nga level sa langis dapat mas taas sa itaas sa bushing. Usa ka glass oil level gauge (o oil level indicator) gigi-install sa side sa conservator aron mapantayan ang real-time nga changes sa level sa langis.

Mga Tipo sa Oil Conservators

Karon, adunay tulo ka pangunahan nga tipo sa transformer oil conservators:

• Capsule-type conservator: May rubber capsule sa loob nga nag-isolate sa langis sa transformer gikan sa external atmosphere samtang naghatag og espasyo para sa thermal expansion ug contraction.

• Diaphragm-type conservator: Gigamit ang rubber diaphragm aron mag-separate ang langis gikan sa hangin ug naghatag og kinahanglan nga volume para sa thermal expansion ug contraction.

• Corrugated-type conservator: Naggamit og metal bellows expansion device aron mag-isolate ang langis gikan sa atmosphere ug maka-accommodate sa changes sa volume sa langis. Ang corrugated conservators gihatagan og internal oil ug external oil types, ang internal oil type may mas maayo nga performance pero mas dako.

Mga Pamaagi sa Pag-seal sa Oil Conservators

• Open-type (non-sealed) conservator: Ang langis sa transformer direkta nga exposed sa external air. Kini nga disenyo may poor sealing, makapukaw sa langis sa moisture ug oxidation, resulta sa excessive moisture ug gas content, nga mobati sa safe operation sa transformer. Kini nga tipo gi-phase out na ug makita lang sa uban ka low-voltage, small-capacity transformers.

• Capsule-type conservator: Equipped with an oil-resistant rubber capsule inside the conservator to isolate the oil from air. The capsule communicates with the atmosphere through a breather pipe and desiccant, expanding and contracting with oil level changes. However, the capsule is susceptible to aging and cracking, allowing moisture and air to enter the oil, leading to oil degradation, reduced insulation performance, and increased dielectric loss. Regular silica gel replacement is required, and severe cases may necessitate oil filtration or power outage maintenance. Its application is gradually decreasing.

• Diaphragm-type conservator: Uses a diaphragm structure made of two layers of nylon fabric sandwiched with chloroprene rubber and coated with nitrile rubber on the outside. However, it has high requirements for installation and maintenance processes, with issues such as oil leakage and rubber component damage affecting power supply safety, reliability, and operational cleanliness. Its use is also gradually decreasing.

• Metal corrugated (internal oil) sealed conservator: Uses a metal elastic element as a compensator, a mature technology widely used in power systems for over 20 years, extending the technology of plate-type metal expanders used in instrument transformers.

• Internal oil vertical conservator: Uses bellows as oil containers, with multiple bellows connected in parallel and vertically installed on a base, an external dust cover added, and oil volume compensation achieved by the vertical movement of the bellows, with a mostly rectangular appearance.

• External oil horizontal conservator: Uses bellows as an air bladder, horizontally placed inside the conservator cylinder, with insulating oil filled between the outer side of the bellows and the cylinder, and the inside of the bellows connected to the external air. Oil volume compensation is achieved by the expansion and contraction of the bellows, changing the internal volume of the conservator, with a horizontally placed cylindrical appearance.

Features of Metal Corrugated Oil Conservator

• The core cavity is equipped with a damper as a pressure protection device, which can mitigate the impact of sudden increases in internal oil pressure on the conservator body. When the pressure reaches the limit, the core ruptures to release pressure, protecting the transformer body and enhancing operational reliability—a unique feature not found in other conservators.

• The core consists of one or more bellows units, with an external protective cover. The outside of the core is exposed to the atmosphere, facilitating good heat dissipation and ventilation, promoting oil circulation, reducing internal oil temperature, and improving operational reliability.

• The oil level indicator moves synchronously with the core's expansion and contraction, offering high sensitivity. Oil level changes can be directly observed through a viewing window on the protective cover, providing intuitive and reliable readings. A limit switch for oil level alarm is installed on the protective cover, meeting the requirements for unattended operation.

• No false oil level phenomenon: Traditional conservators struggle to completely expel air, potentially causing false oil levels. This design, with its sensitive core movement and a balance steel plate creating slight positive pressure, effectively expels internal air until the desired oil level is reached, eliminating false oil levels.

• Metal bellows expanders are not suitable for on-load tap-changer oil tanks: The on-load tap-changer, a key component of the transformer, frequently adjusts voltage based on load conditions during operation. Arcs generated during adjustment lead to oil decomposition and gas production. The limited volume of fully sealed metal bellows expanders hinders gas release, requiring frequent on-site venting. Therefore, manufacturers and users do not recommend using fully sealed metal bellows expanders for small conservators of on-load tap-changers.