777 / 2022-03-31 21:45:44

Research on Vibration and Noise Characteristics of Shell-type and Core-type Nanocrystalline High-frequency Transformer

high frequency transformer,vibration,noise

Purpose/Aim

The high-frequency transformer (HFT) of large capacity in DC/DC converter can achieve the voltage and power transmission, the electrical isolation between the high and low voltage sides through the magnetic coupling, and the electrical control of DC/DC converter on both sides. As a new type of soft magnetic material, nanocrystalline magnetic material has excellent electromagnetic properties (high permeability and low loss). The application of nanocrystalline material to HFT core instead of conventional silicon steel sheet can significantly reduce the iron loss and improve efficiency. However, due to the high frequency and large air gap in the HFT core, the vibration HFT is large, and the noise is sharper than traditional power frequency silicon steel transformer. Therefore, it is significant to study the vibration and noise characteristics of the HFT.

Experimental/Modeling methods

The test platform is built to test the vibration and noise of the core-type and shell-type HFT, the noise is measured at the front and side of HFT, and the distance is 30cm. The piezoelectric acceleration sensor is used to measure the vibration acceleration of HFT. The sensitivity and range of vibration acceleration sensor used in experiment are 100mV/g and ±50g respectively.

Results/discussion

The vibration of the upper part and air gap of the shell-type HFT is more serious, and the vibration of the upper part of the core-type HFT is more serious. The vibration of HFT gradually become larger with the increase of the magnetic flux density. The noise of core-type HFT is significantly smaller than that of shell-type HFT under the same magnetic flux density. Therefore, shell-type structure should be selected as much as possible in the design stage of HFT.

Conclusions

In this paper, a method for measuring magnetostriction of nanocrystalline material through the measurement for magnetic rings is proposed, which provides a solution for the problem of nanocrystalline magnetostriction. The vibration and noise of a core-type and shell-type nanocrystalline HFT (10 kVA/5kHz) are tested and analyzed.