why is the sound of dry type transformer high
The sound of dry-type transformers is one of the important failures that often occur during operation. For the sound problems of dry-type transformers, we must improve the solution to the abnormal sound of dry-type transformers, and the sound problems of dry-type transformers mainly manifested in excessive sound. So what is the cause of the situation?
(1) The voltage of the power grid is too high, which increases the working magnetic density of the transformer and increases the noise of the product. At this time, by properly adjusting the transformer tap voltage, the noise of the product can be reduced.
(2) When the transformer has a thyristor rectifier, the current and voltage of the low-voltage side circuit contain a large number of higher harmonics. If the transformer adopts the YynO connection method, because the high-voltage side adopts the Y-type connection method without a neutral line, the third harmonic current cannot flow, thereby distorting the main magnetic flux in the core. In addition to the fundamental wave flux, it also contains a large number of higher harmonics, so the noise increases significantly. Therefore, installing an isolation transformer between the Dynll-connected transformer and the SCR device can reduce the noise of the product.
(3) When the three-phase load of the transformer is severely unbalanced, a large zero-sequence current appears on the low-voltage side. A large zero-sequence magnetic flux is generated in the core. The zero-sequence magnetic flux is a positive-spin wave at the fundamental frequency. Its presence changes the magnitude and phase of each magnetic flux, which makes the core single or two magnetic densities seriously increase or saturate, which significantly increases the transformer noise. Dynll-connected dry-type transformers can reduce noise.
(4) When the transformer core is grounded at multiple points or the core chip is short-circuited, it will distort the core's local magnetic flux and cause the transformer noise to increase significantly. In such cases, as long as the core fault is eliminated, the transformer noise can be reduced.
(5) The installation place of dry-type transformer has a great influence on the measurement and feeling of transformer noise. When the four walls of the transformer installation site are smooth and the distance between the transformer and the four walls is less than 3M, the dry type transformer noise is prone to echo, so the noise measurement value and feel are significantly larger than the noise emitted by the dry type transformer body. In this case, the user can lay sound-absorbing materials on the four walls to reduce the echo of the noise, thereby achieving the purpose of reducing noise.
In short, the resin cast dry-type transformer mainly generates noise from the iron core. The reason for the increase noise is related to product design, noise propagation path, product operating conditions, load characteristics, installation environment and other factors. Measures to reduce transformer noise must consider comprehensive economic costs, analyze the actual causes of noise generation and increase and then comprehensively manage. For the product's own reasons, the manufacturer must research and resolve. When the product's operating conditions, load characteristics, installation environment and other factors affect the noise of the product, it must be resolved with the user.
The above are the main reasons for the excessive sound of common dry-type transformers and the main reasons. When these reasons appear, it indicates that there is a problem with your dry-type transformer.