Cast Coil Dry Type Transformer Structure
Dry-type transformer is an important electrical appliance, and its performance and role in the process of our production and life are also relatively large. The composition of dry-type transformer is relatively complex, and various parts play a role. There are also many functions, and the various functions and functions of the dry-type transformer should be continuously guaranteed. What are the basic internal structures of dry-type transformers and the functions of internal components?
1. Iron Core
The iron core is used as the closed magnetic circuit of the dry-type transformer and the skeleton of the fixed winding and other components. In order to reduce the reluctance and reduce the hysteresis loss and eddy current loss caused by the alternating magnetic flux in the iron core, the iron core of the dry-type transformer is mostly made of thin silicon steel sheets stacked. The iron core of dry-type transformers has two basic forms: core type and shell type.
The iron core of the core dry-type transformer is composed of an iron core column, an iron yoke and a clamping device, and the winding is sleeved on the iron core column, as shown in Figure 3.3. The core-type dry-type transformer has a simple structure, and the winding assembly process and insulation process are simpler than those of the shell-type dry-type transformer. Most of the domestic three-phase oil-immersed power dry-type transformers adopt the core-type structure.
The iron core of the shell-type dry-type transformer surrounds the four sides of the winding, just like the outer casing of the winding. The mechanical strength of shell-type dry-type transformers is relatively high, but the manufacturing process is complicated and the materials used are more, which are rarely used in general power dry-type transformers.
2. Winding
The winding is the circuit part of the dry-type transformer. The primary winding absorbs the energy of the power supply, and the secondary winding provides electricity to the load. The windings of dry-type transformers are made of flat or round wires wrapped with insulating materials, and there are two kinds of copper wires and aluminum wires. According to the arrangement between the high and low voltage windings, the windings of dry-type transformers have two basic forms: concentric and overlapping.
3. Other parts
(1) Fuel tank
The body of the dry-type transformer is placed in an oil tank filled with dry-type transformer oil with high dielectric strength and high ignition point.
When the dry-type transformer is running, both the iron core and the windings emit heat, which makes the dry-type transformer oil hot. The hot dry-type transformer oil convects in the oil tank, transfers the heat to the tank wall and the radiator on it, and then radiates to the surrounding air or cooling water to achieve the purpose of heat dissipation, so as to keep the temperature in the transformer at a reasonable level superior.
(2) Oil conservator (also known as oil pillow)
The oil conservator is installed above the oil tank and communicated with the oil tank through the connecting pipe to protect the dry-type transformer oil.
Dry-type transformer oil will easily absorb moisture and impurities in the air when it is in contact with the air for a long time at a relatively high temperature, so that the dielectric strength and heat dissipation capacity of the dry-type transformer oil are correspondingly reduced. The purpose of installing the oil conservator is to reduce the contact area between the oil surface and the air, reduce the temperature of the oil surface in contact with the air, and exchange the air on the upper part of the oil conservator with the outside air through the hygroscopic agent, thereby slowing down the dry-type transformer oil. Moisture and aging rate.
(3)Gas relay
The gas relay device is installed in the connecting pipeline between the oil tank and the oil conservator, and plays a role in protecting the dry-type transformer from short-circuit, overload, oil leakage and other faults.
