What are the main factors causing abnormal noise in high-frequency transformers?

High-frequency transformers sometimes make noise during operation, and one of the reasons for this is the cooler. Because the fan generates noise, the human ear is of course more sensitive to this broadband harmonic than the harmonics generated by the core frequency. The dominant frequency depends on many factors, including fan speed, number of blades and blade shape. The sound power level depends on the number of fans and the speed.

Like the mechanism of the noise of the high-frequency transformer body, the noise of the cooling device is also caused by their vibration, and the source of its vibration is:

1. The vibration generated by the cooling fan and oil pump during operation;

2. The vibration of the high-frequency transformer body is transmitted to the cooling device through insulating oil, pipe joints and their assembly parts, which intensifies the vibration of the cooling device and increases the noise.

In addition, when the core is heated, due to the change of resonant frequency and mechanical stress, its noise will increase with the increase of temperature. The environment of the operating site (such as surrounding walls, buildings and installation foundations, etc.) also affects the noise. For many strong wind cooling transformers, the cooler fan is a more obvious noise source than the transformer itself.

What are the main factors causing abnormal noise in high-frequency transformers? 

From the perspective of high-frequency transformer manufacturing process, there are mainly the following aspects:

1. The working magnetic flux density of the transformer is too high, close to saturation, and the leakage magnetic flux is too large, which generates noise;

2. The material of the core is too poor, the loss is too high, and noise is generated;

3. The harmonic content and DC component in the working circuit will also cause noise in the core and even the coil;

4. Transformer manufacturing process:

a. The coil is wound too loosely;

b. The coil and the core are not firmly fixed;

c. The core is not firmly fixed;

d. There is an air gap between EI, which generates “buzzing” during operation;

e. The two silicon steel sheets on the outside of the E-type core are not properly handled, which is very easy to generate noise;

f. Dipping process treatment: viscosity control of insulating paint;

g. The metal (magnetic) structural parts on the outside of the transformer are not firmly fixed;

5. If it is a high-voltage product, there will be noise if the insulation is not well handled.

●Zhongshan XuanGe Electronics is a factory specializing in the production of high-frequency transformers, inductors, filters and other electronic components, with 15 years of manufacturing experience.
●The company has experienced skeleton design engineers, core design engineers, transformer development engineers and other technical personnel and R&D teams, which can be customized according to customer’s special requirements to meet the needs of different customers.