First level energy-efficient distribution transformer

First level energy-efficient distribution transformerThe primary and secondary coils of a regular transformer are coaxially wound around a core column, with a low-voltage winding inside and a high-voltage winding outside. The primary and secondary coils of the welding machine transformer are installed on two iron core columns respectively.

When a transformer is operating with a load, as the secondary current increases, the transformer must maintain the main magnetic flux in the iron core constant, and the primary current must also increase accordingly to achieve balanced secondary current.

The secondary active power of a transformer is generally equal to the rated capacity of the transformer (KVA) multiplied by 0.8 (transformer power factor)=KW.

Power transformers mainly include:

A、 Moisture absorber (silicone cylinder): It contains silicone, and the insulation oil in the oil storage tank (oil pillow) is connected to the atmosphere through the moisture absorber. The desiccant absorbs moisture and impurities in the air to maintain good insulation performance of the internal winding of the transformer; Silicone discoloration and deterioration can easily cause blockage.

B、 Oil level gauge: reflects the oil level status of the transformer, usually around+20O. If it is too high, oil should be drained, and if it is too low, oil should be added; In winter, when the temperature is low and the load is light, the oil level does not change much, or the oil level slightly decreases; In summer, when the load is heavy, the oil temperature rises and the oil level also slightly increases; Both are normal.

C、 Oil pillow: Adjust the oil level in the tank to prevent transformer oil from oxidizing too quickly, and there is an oil filling hole on the upper part.

D、 Explosion proof pipe: prevents sudden accidents from causing explosion hazards due to pressure accumulation in the fuel tank.

E、 Signal thermometer: monitors the operating temperature of transformers and sends signals. The indication is the upper oil temperature of the transformer, and the temperature of the transformer coil should be 10 ℃ higher than the upper oil temperature. The national standard stipulates that the maximum working temperature of transformer windings is 105 ℃; When the ambient temperature is 40 ℃, the upper layer temperature should not exceed 95 ℃, and it is usually advisable to set the monitoring temperature (upper layer oil temperature) at 85 ℃ or below.

F、 Tap changer: By changing the tap of the high-voltage winding, increasing or decreasing the number of turns of the winding, the voltage ratio can be changed.

U1/U2=W1/W2, U1W2=U2W1,

∴：U2=U1W2/W1。

First level energy-efficient distribution transformerGenerally, transformers are used for no-load voltage regulation and require power outage: they are divided into three levels: level I, level II, and level III+5%, 0%, and -5% (primary voltage is 10.5KV, 10KV, and 0.95KV, and secondary voltage is 380V, 400V, and 420V). They are usually placed in level II when leaving the factory.

G、 Gas signal relay: (gas relay) for light and heavy gas signal protection. The upper contact is a light gas signal, which is generally used for signal alarm to indicate abnormal operation of the transformer; The lower contact is a heavy gas signal, which sends out a signal and triggers the circuit breaker to trip, trip, or sound an alarm; Generally, when a gas relay is filled with oil, it indicates that there is no gas. When there is gas in the fuel tank, it will enter the gas relay. When it reaches a certain level, the gas will squeeze out the stored oil and cause the contacts to move; Open the outer cover of the gas relay, there are two adjustment rods on top, and unscrew one of the caps to release the gas inside the relay; The other adjustment lever is the protective action test button; Insulated gloves must be worn and safety emphasized during live operation.

In order to ensure the economic and safe operation of transformers and guarantee a certain service life, manufacturers usually specify the rated values of their products. And conduct product testing according to the rated value before the equipment leaves the factory, and mark the data of rated operation on the transformer nameplate (Table 1).