the principle of Transformer

Farady transformer   is converting AC voltage, current and impedance of the device, when the primary coil through AC current, core (or cores) and then generates an alternating magnetic flux, so that the secondary coil induces a voltage (or current). The transformer core (or cores) and coil, the coil has two or more windings, wherein the power supply is called the primary coil winding, the secondary winding is called the rest of the winding. In the generator, either the coil moves through the magnetic field or magnetic field moves through the stationary coil, can EMF in the coil, in both cases, the value of the magnetic flux are the same, but there is the number of the magnetic flux intersecting the coil chain change, which is the principle of mutual induction. Transformer is a kind of mutual use of electromagnetic induction, the transformation of voltage, current and impedance of the device. Press the Power Phase Classification: single-phase transformer, three-phase transformer, multi-phase transformer.

For oil-immersed transformer, how to determine the top up?

Transformer oil fill is no absolute standard. Tubing, can observe the normal standard pillow top oil is not less than the minimum bit tick, tick no higher than the highest bit. In general, the oil immersed distribution transformer is not running, the oil level in the fifth to one-third of the tubing, tubing run oil level in half at Also, thermal expansion and contraction caused by the ambient temperature influence oil level.

Water fast burning transformer oil how to do?

- ★ 1, oil immersion transformers, transformer coils are soaked in insulating oil heat. "Transformers Water" First insulating properties of insulating oil has been violated, you should immediately stop running, in order to avoid breakdown failure.
- ★ 2, transformer insulating oil is very important, and there is moisture absorption characteristics, humidity of the weather are not exposed to the air, water after scrapped. Dried, filtered and so is purely a joke!
- ★ 3, should: ①, stop running as soon as possible; ②, completely let go of the insulating oil; ③ try drying oil type transformer, especially high-voltage winding; ④, after thoroughly dried before they can add new insulating oil; ⑤, high pressure shake shake table testing insulation, only after passing into operation.

How oil-immersed transformer maintenance and repair?

Oil-immersed transformer maintenance and repair has been a lot of transformer users urgent need to understand the problem, although dry-type transformers have several advantages over oil-immersed transformers, oil-immersed transformers but proper maintenance, but also has its own unique advantages . Let us look at oil-immersed transformer maintenance and repair methods it.

1, to prevent leakage of oil: oil-immersed transformers filled with 100kva distribution transformer oil in the tank, the fastener assembly rely on oil pressure and the sealing rubber elements. Mifengbuyan is the main transformer oil leakage, we should pay particular attention to the care and maintenance. Small bolts are loosened through vibration, if loose should intensify solid and intensify the degree should be appropriate and should be consistent throughout. Rubber is broken or seriously deformed. Then updatable rubber parts, replacement should pay attention to its model specifications are the same, and clean the sealing surfaces.

2, the prevention of transformer moisture: Transformer is a high-voltage equipment, required to maintain its good insulating properties. Oil-immersed transformers easily damp, damp prevention is one of the main measures taken by the maintenance of the transformer. To do this requires the user to note the following: the purchase of the transformer, power supply bureau should immediately do the transfer test; immediate installation of moisture, a transformer capacity of 100 kVA and above all with breathers. A transformer should be immediately transported to the site to install breather to prevent the body from moisture inside the device. Monitoring breathers in the silica gel should be replaced immediately after wet. Breathers in silica gel, play a role in the absorption of moisture and protect the transformer. After saturated with moisture, silica gel changes color, then be replaced with new dry silica gel. Orders should pay attention to, to try to reduce the storage time before the transformer power transmission. After the 13.8kv single phase transformer  manufacturing, storing easily when wet, damp storage longer the more serious, it should be good schedule to shorten the storage time. Capacity of 100 KVA and below the small transformer, no moisture absorption device. Oil within the oil pillow easy to damp, and the oil pillow water. Do not send electricity from the store more than six months or of more than one year in operation, the oil inside the transformer oil has been severely damp pillow. If you want to be when lifting transportation, maintenance fuel, oil drain valve, hanging core, etc., should be through the oil drain plug pillow below the waste oil within the oil pillow let go, and wipe with a dry cloth, sealed to avoid the oil pillow inside dirty oil into the tank. Transformer operation, should always pay attention to the oil level, change oil temperature, voltage, current, if abnormal situation should be timely analysis and processing. When the transformer is installed non-aluminum wire, aluminum row and so connected with the guide rod copper transformer in order to avoid corrosion guides.
3, oil change and drying transformer: Transformer idle for too long, the running time is too long or other natural factors, resulting in transformer insulation deterioration, internal water or oil degradation and other phenomena, this time must the transformer oil change and drying process. Transformer oil change: first the body of hanging out, put the net and wash tank waste oil, such as device should rinse the body with oil. To be injected into the body of the new oil after drying, replacing all the oil and rubber seals. After passing the test before hanging run. Transformer drying process: the body of the drying methods more. When the user to bake drying method available zero-phase sequence, vortex drying, short drying, oven drying method. Larger capacity and voltage of 35 kV transformer pole, it is best to send the manufacturer for vacuum drying. This will not only ensure that the transformer insulation drying thoroughly, without making the aging of insulation.

Superiority analysis skills on oil-immersed transformers

Oil-immersed transformers mainly by multi-loop high pressure switch system, armored bus, 10kva step up transformer induction automation system, communication, remote metering, capacitance compensation and DC power supply and other electrical unit combination, means in a moisture-proof, rust-proof, dust-proof , rodents, fire, theft, insulation, totally enclosed, removable steel structure housing, electromechanical integration, fully enclosed run, mainly has the following characteristics:
(1) high degree of automation: the station of intelligent planning, maintenance system, the choice of substation automation equipment Microcomputer induction, lax device, to be completed "four remote", namely telemetry, remote, remote control, remote adjustment, each unit has a separate operation function, relay protection function fully, operating parameters can be set from afar, on the cabinets humidity, temperature control and remote smoke alarm, no duty demands satisfaction; according to the needs of remote monitoring can also complete the picture.
(2) Advanced Skills safe and reliable: the choice of the current domestic housing some preemptive skills and skills, housing usually use galvanized steel, construction materials and the choice of specification container production skills, have excellent corrosion resistance, to ensure that 20 years does not rust, regulator the transformer selection aluminum gusset closure plate, sandwich selection fireproof insulation materials, cabinets means air conditioning and dehumidification equipment, test prefabricated compact transformer equipment operating from outside the natural environment and the impact of climate pollution, ensuring at -40 ℃ ~ + 40 ℃ bad Under normal operation conditions. Equipment cabinets fully enclosed high voltage switchgear selection (eg: XGN type), dry-type transformers, dry-type transformers, vacuum circuit breakers, stretched spring operating organizations, rotary switches and other domestic skills preemptive blocking equipment, goods without exposure to live some, is fully enclosed, fully insulated structure fully capable of zero electric shock arrives, the station can be completed oil-free operation, high security, the second choice of computer automation systems induction can be completed unattended.
(3) factory prefabrication: The oil-immersed transformers planning, according to practice as long as the planner needs substation, to plan a main wiring diagrams and equipment outside the box, you can select the type of box becomes standard and supplied by the manufacturers, all equipment a device in the factory, debugging qualified, real complete substation construction factory, shorten production cycle planning; site means only cabinet position, contact between the cable box, cable outlet adapter, maintain calibration value, transmission experiments and other needs commissioning operations, all from the device to substation put into operation only about 5 to 8 days time, greatly reducing the construction period.
(4) a combination method is sensitive: oil-immersed transformers due to the relatively compact structure, each box constitutes an independent system, which makes changing the combination method is sensitive, on the one hand, we can all choose oil-immersed, that is to say, 35kV and 10kV equipment all inside the device, consisting of a full oil-immersed transformers; switch boxes can only 10kV, 35kV equipment outdoor equipment, 10kV equipment and control security system inside the device, on this combination approach is particularly suitable for rural power grids The transformation of the old station, which does not move original equipment 35kV, 10kV only means a switch box can be reached unattended needs. Always, oil-immersed transformer no fixed combinations,single pole transformer abb use units can be freely combined according to the actual situation of some form, to the satisfaction of the needs of safe operation.

Distribution transformer

distribution transformer is one of the important industrial and mining enterprises and civil equipment for power distribution systems, it will be 10 (6) kV or 35kV network voltage falls below 230 / 400V bus voltage users. Such products applicable to the exchange 50 (60Hz, three-phase maximum rated capacity 2500kVA (single-phase maximum rated capacity of 833kVA, is generally not recommended to use a single-phase transformer), the (outer) use, the capacity can be installed indoors in 315kVA and below in the bar, the ambient temperature is not higher than 40 ℃, not lower than -25 ℃, the highest daily average temperature of 30 ℃, the highest annual average temperature of 20 ℃, relative humidity less than 90% (ambient temperature 25 ℃), the altitude does not exceed 1000m. If inconsistent with the above conditions, according to relevant provisions of GB6450-86, and make appropriate quota adjustments.Depending on the number of phases, it can generally be divided into three-phase transformers and single-phase transformer.

Oil immersed transformer should pay particular attention to their fire safety measures

1, more than 2500kg of fuel in oil-immersed transformers and oil between the 600kg-2500kg of oil-filled electrical equipment, the fire spacing should be less than 5m. 2, when the spacing between adjacent fire between the two oil-immersed transformer does not meet the requirements should be set at the top of the fire wall or fire wall add fire water curtain. You can only set fire wall or fire water curtain between the single phase pole mounted transformer . 3, when the plant from the outside facades with oil-immersed transformer is smaller than the outer edge of the provisions of the specification table, the exterior wall firewall should be used. Distance from the outer edge of the wall and transformer of not less than 0.8m. 4, oil-immersed transformer factory facades from the outer edge of less than 5m, the total thickness of the transformer plus 3m 3m below the horizon and within range of each outer edge plus side, should open doors and windows and holes; it outside its scope Doors and fixed windows firewall, its fire resistance of not less than 0.9h. 5, oil-immersed transformers and other oil-filled electrical equipment during a single fuel than 1000Kg, set oil storage pits and a common set sump. 6, oil immersed power transformer shall be related to the current specification, provided a fixed water spraying fire extinguishing system. Oil-immersed transformer plant should be set up in a separate room, the door of the room should be B fire doors open outwards, and direct access to the outdoors or corridors, not open to other rooms.

Farady oil immersed power transformer

Oil-immersed power transformers in operation,substations and transformers winding and core heat the oil first pass, and then passed through a cooling medium oil. Cooling oil-immersed power transformers, according to the size of the capacity can be divided into the following categories:
1, the natural oil circulation natural cooling (ONAN type)
2, natural oil circulation-cooled (air-cooled oil-immersed) 3, forced oil-cooled 4-cycle water, forced oil circulation air cooling oil type transformer should pay particular attention to their fire safety measures.

Oil immersed transformer classification and Protection

According to the number of single-phase transformer to distinguish, it can be divided into three-phase transformers and single phase transformer. In a three-phase power system, the general application of the three-phase transformer, when the oversized transport conditions and subject to three phase pad mounted transformer system can also be applied consisting of three single phase pole mounted transformers group. According to the number of windings can be divided into two-winding transformer and three-winding transformers. The transformers are usually two-winding transformer, namely on the core has two windings, one for the primary winding, one for the secondary winding. Three-winding transformer larger capacity transformer (5600 kVA or more) to connect the three different voltage power lines. In special circumstances, also applied more windings.
According to the structure in the form of classification, it can be divided into core type transformers and transformer steel. As compared with the winding package in the core periphery core type transformer; as the core periphery was wrapped in winding transformer steel. But both are slightly different in structure, there is no essential difference in principle. Power transformers are all core type.

Advantages and disadvantages of dry-type transformers and oil transformers

1, dry, oil-immersed transformers occasions What is the difference? What are the advantages and disadvantages of each? Which thermal performance good?
A: The dry cast resin transformer are usually used indoors, fire safety requirements are relatively high occasions. Oil-filled transformers are usually outdoors, of course, also be used indoors, but oil immersed transformer possible in the event of a fault injection and combustion, so indoor use more dangerous. Dry-type transformers are usually not spontaneous, but also high-quality products with flame retardant capabilities. Advantages of dry-type transformers are safe, clean, the disadvantage is the high price, large area, outdoor use difficult; the advantages of oil-immersed transformer is the voltage level can be very high, small footprint, using a wide range, the disadvantage is oil spills, pollution of the environment when failure. Two kinds of transformers follow different standards, temperature requirements are different, different heat dissipation structure is unfair. Structurally speaking, good oil-immersed transformer thermal performance.

Distribution transformer is one of the important industrial and mining enterprises

Distribution transformer is one of the important industrial and mining enterprises and civil equipment for power distribution systems, oil immersed power transformer will be 10 (6) kV or 35kV network voltage falls below 230 / 400V bus voltage users. Such products applicable to the exchange 50 (60) Hz, three-phase maximum rated capacity 2500kVA (single-phase maximum rated capacity of 833kVA, is generally not recommended to use a single-phase transformers) may, within households (outside) the use,oil immersed distribution transformer capacity 315kVA and below can be mounted on the rod, the ambient temperature is not higher than 40 ℃, not lower than -25 ℃, the highest daily average temperature of 30 ℃, the highest annual average temperature of 20 ℃, relative humidity less than 90% (ambient temperature 25 ℃), altitude not more than 1000m. If inconsistent with the above conditions, according to relevant provisions of GB6450-86, and make appropriate quota adjustments.