66KV 69KV 110KV 220KV TWO WINDING POWER TRANSFORMER

POWER TRANSFORMER FEATURES

• Low partial discharge、partial discharge is always less than 100pC;

• Low noise of transformers up to 63MVA is lower than 60dB;

• Low loss:、no-load loss reduced by 20 percent compared with GB/T6541;

• High short-circuit resistance ability;

MANUFACTURING TECHNOLOGY

• TRANSFORMER CORE

High-grade cold-rolled grain-oriented silicon steel sheets are used for core plates. The core plates are made without holes to reduce no-load loss and the risk of core-bolt short 。The sheets are cut by automatic cut-to length line，insuring the burrs to be well below0.02mm.The no-load loss of the transformer is reduced efficiently.

Shoring is used tighten the core and inner-winding. Iron yoke is strained by epoxy resin fiberglass rope. Besides, there are three fixations between the iron yoke and tank, so the body and tank are too tight to detach during transportation.

• TRANSFORMER WINDINGS

Generally the H.V Winding is of inter leaved and continuous winding to improve the performance under impulse voltage and obtain uniform distribution voltage. The pressboard spacers are rounded at the edges so as to improve insulation reliability Oil flowing within the winding will be able to lower the coil temperature rise and hot-spot temperature thus ensuring a prolonged insulating service life.

Both the H.V and M.V. winding are generally provided with separate voltage regulating windings, so the ampere turns of all the windings are completely balanced. These can effectively eliminating the axial electrodynamics force during external short circuit and improve the dynamic stability under external short circuit.

• OIL TANK

Bell-jar type tank is most commonly used the tank wall is made into a corrugated shape by heave press, This will reduce the welding work and the mechanical strength will be much improved Double oil resistant rubber synthetic gasket is provided between the flanges of the upper and lower tank Position limiting device usually be fixed on the flange of the lower tank.

• COOLING EQUIPMENTS AND TRANSFORMER ACCESSORIES

The cooling method of the transformer generally including oil natural circulation (ONAN) and air natural or forced circulation(ONAF).Transformers are designed to operate at full load when fans are in operation, and at 70% full load when fans shut down. Plate fin type radiators are used for cooling A more compact size can be obtained for transformers equipped with such radiators .The fans generally blow horizontally with low speed and low noise。The operation of fans be controlled by both the oil temperature and a control cabinet is installed on transformer tank.

Conservators are of diaphragm bag type. The bag is made of resistant airtight composite material， separating the air inside the bag and the oil outside. For further reliability, the air chamber of diaphragm bag is breathed through silica gel breather.

TECHNICAL DATASHEET FOR TWO WINDING POWER TRANSFORMER

OUTLINE DRAWING FOR TWO WINDING POWER TRANSFORMER

1-Conservator

2-H.V. Bushing

3-H.V. Neutral Bushing

4-Transformer Body

5-Radiator

6-On-Load Tap Changer

7-L.V. Bushing