S11-250KVA/10KV/0.4KV oil-immersed transformer production process.

1. Cutting line:

This process is to disassemble the roll of enameled wire with a fixture, cut it into the specified length, pay attention to the storage of enameled wire, do not damage the enameled wire;

2. Wrapping the ring

The operation content of this process is: according to the work instructions, the specified number of turns are wound on the specified magnetic ring with the specified enameled wire.

Check that the magnetic ring is used correctly;

Check that the enameled wire is used correctly;

The number of wounds should be correct;

The needle used for threading should be polished and smooth by special personnel to prevent the tip of the needle from piercing the enameled wire during threading, and the high pressure defect will be formed when the finished product is finished;

Ring quality requirements:

The winding is evenly distributed, and sometimes a gap of a certain width should be left according to the requirements of the work instructions. The uniformity of the winding distribution can greatly improve the final leakage inductance and distributed capacitance of the product;

The windings should not overlap. Overlapping windings will bring two defects, one is to increase the leakage inductance of the product; The second is that the entire outer diameter of the semi-finished magnetic ring is increased after the winding overlap, which is not conducive to the placement of the magnetic ring when assembling the finished product;

Winding is not discountable. After the winding is discounted, it will bring at least three or more defects: after the winding is discounted, the enameled layer of the enameled wire will be damaged, and the product will form a hidden danger of poor pressure resistance; The enameled wire after the discount is easy to break;

After the enameled wire is discounted, the length is increased, and its DC resistance is increased, and the DCR of the products with stricter DC resistance requirements will be restricted.

Winding tension. Excessive winding will lead to an increase in the leakage inductance of the product;

The winding is not staggered, which is the same as the harm caused by the winding not overlapping;

The length of the remaining lead should meet the requirements of the work instruction;

When the remaining line is required to distinguish the long and short lines, it must be strictly distinguished, or supplemented by different colors to distinguish them;

The storage of the magnetic ring should be placed in a small specified area to avoid damage and loss of the magnetic ring;

The semi-finished products after winding the ring should be placed neatly, and each lead should not be curled.

S11-250KVA/10KV/0.4KV oil-immersed transformer design methods

1. S11-250KVA/10KV/0.4KV oil-immersed transformer cross-sectional area is clear The cross-sectional area a of the transformer core is based on the total output power p of S11-250KVA/10KV/0.4KV oil-immersed transformer. When designing the scheme, if the load base is stable and will not change, the cross-sectional area of the transformer core is relatively usable The theoretical value is a = 1.25 。 If the load changes greatly, such as some machinery and equipment, some audio frequency, power amplifier switching power supply, etc., then the cross-sectional area of S11-250KVA/10KV/0.4KV oil-immersed transformer should exceed the general basic theoretical calculation value as much as possible, so as to ensure that there is sufficient output power output capacity.

2. Clarity of the number of turns per volt The number of turns of S11-250KVA/10KV/0.4KV oil-immersed transformer is determined by the cross-sectional area of the transformer core and the quality of the ferrite core. The test proves that the value of the material per volt turn is wider than that of the book, and the value of the counting formula obtained by the book is reduced by 10%~15%. For example, a 35w switching power supply S11-250KVA/10KV/0.4KV oil-immersed transformer, general It is estimated that (8500 gauss) should be around 7.2 turns per volt, but in fact, only 6 turns per volt is required, so that the no-load current of the S11-250KVA/10KV/0.4KV oil-immersed transformer after winding is around 25ma. So so After moderately reducing the number of turns, the wound S11-250KVA/10KV/0.4KV oil-immersed transformer can not only reduce the internal resistance, but also prevent the inconvenience of being wound down due to the ferrite core of general specifications, but also save the cost, and then improve the cost performance.

3. The wire diameter of the enameled wire is clear The wire diameter should be clear according to the load current, because the enameled wire has a large difference in the amount of current in different natural environments, so the strength to clarify the wire diameter is also very large. Generally, when the heat pipe heat dissipation standard is not ideal and the working temperature is relatively high, the current density of the enameled wire should be 2A/mm2 (wire diameter). If the S11-250KVA/10KV/0.4KV oil-immersed transformer continues to work in the middle of the load current base, the basis will not change, but itself The heat pipe heat dissipation standard is good, and the working temperature is not high, the current density of such enameled wire is 2?5a/mm2 (wire diameter), if the current amount of S11-250KVA/10KV/0.4KV oil-immersed transformer can only be 1/2 of the larger working current, the current density of such enameled wire is 3~3.5a/mm2 (wire diameter). The current density of enameled wire of the audio frequency S11-250KVA/10KV/0.4KV oil-immersed transformer can be 3?5~4a/mm2 (wire diameter). In this way, the specimen can not only ensure the quality and quantity, but also greatly reduce the cost.