- BrandАО МЭТЗ, Алагиум, Китай
- Country of manufactureKazakhstan
- ColorGrey
- Number of phases3
- Number of coils2
- Method of cooling the windingsOil
- Type of constructionRod type
The transformer is intended for food of chains of automatic lock - out from VL of longitudinal power supply of the railroads. The transformer can be used to food of chains of low - power consumers of other branches.
The transformer is manufactured in a climatic modification of "UHL" and "T" of category of placement 1 in accordance with GOST 15150. Values of air temperature at operation - from minus 60 °C to plus 40 °C for execution of "UHL1" and from minus
10 °C to plus 55 °C for execution of "T1".
The transformer has no own protection against the resonant phenomena and switching retension in a network.
Working situation - vertical.
Technical characteristics of the OLZ - 1,25/27,5 transformer
Parameter | Value |
Class of tension, kV | 27 |
The largest working tension, kV | 30 |
The rated voltage of primary winding, In | 27500 |
The rated voltage of a secondary winding, In, on taps: X - a1 X - a2 X - a3 X - a4 X - a5 |
218 224 230 236 242 |
Rated power, In · And | 1250 |
Nominal frequency, Hz | 50 |
Current of idling, % , no more | 35 |
Losses of idling, W, no more | 50 |
Tension of short circuit, % | 4,5±0,45 |
Scheme and group of connection of windings | 1/1 - 0 |
Type of isolation | cast |
Test tension, kV: one - minute industrial frequency composite storm pulse the storm impulse which is cut off |
70 170 200 |
Weight, kg | 90 max |
General view of the power OLZ - 1,25/27,5 transformer
Schematic electric circuit of the power OLZ - 1,25/27,5 transformer
Terminal box of the power OLZ - 1,25/27,5 transformer
Coolers
The cooling equipment takes away hot oil in the top part of a tank and returns the cooled oil in the lower lateral part. The refrigerating unit has an appearance of two oil contours with indirect interaction, one internal and one external contour. The internal contour transfers energy from the heating surfaces to oil. In an external contour oil transfers heat to the secondary cooling environment. Transformers are usually cooled with atmospheric air.
Types of coolers:
- Radiators, happen different types. Generally they represent a set of flat channels in plates with a face welded seam which connect the top and lower collectors.
- The corrugated tank is at the same time both a tank and the cooling surface for distributive transformers of low and average power. Such tank has a cover, corrugated walls of a tank and the lower box.
- Fans. For big knots use of suspended fans under radiators or sideways from them for ensuring the compulsory movement of air and natural oil and compulsory air (ONAF) cooling is possible. It can increase load ability of transformers approximately by 25% .
- Heat exchangers with compulsory circulation of oil, air. In big transformers assignment of heat by means of natural circulation through radiators demands a lot of place. The need for space for compact coolers is much lower, than for simple radiator batteries. From the point of view of economy of the place it can be favorable to use compact coolers with a considerable aerodynamic resistance that demands application of compulsory circulation of oil by means of the pump and powerful fans for air forcing.
- Oil - water coolers, as a rule, represent cylindrical tubular heat exchangers with removable tubes. Such heat exchangers are very widespread and represent classical technology. They have various application in the industry. More modern designs, for example, flat heat exchangers of membrane type, did not enter practice yet.
- Oil pumps. Circulation pulsers for the oil cooling equipment are special compact, completely tight designs. The engine is shipped in transformer oil - omental boxes are absent.
Equipment for regulation of tension
Main article: Regulation of tension of the transformerThe majority of transformers is equipped with devices for change of coefficient of transformation by addition or shutdown of number of part of rounds of a winding.
Depending on a design regulation of tension of the transformer on secondary windings can be made by means of the switch of number of rounds of the transformer or bolted connections by the choice of provision of crossing points or connection of the corresponding conclusion from the corresponding set at the cut off power and grounded transformer. By means of such control devices tension on secondary windings changes in small limits.
Kinds of switches of number of rounds of the transformer:
- Switches of number of rounds without loading - the switches without excitement (SWE)
- Switches of number of rounds under loading - the regulation under loading (RUL)