Magnetic core high-frequency loss calculation method under symmetric/asymmetric rectangular voltage excitation

Abstract

The invention discloses a method for calculating high-frequency loss of a magnetic core under symmetric / asymmetric rectangular voltage excitation, and the method comprises the steps: deducing ascending branch and descending branch magnetization rate expressions of corresponding trapezoidal and triangular magnetic flux density waveforms according to symmetric and asymmetric rectangular voltage excitation waveforms; calculating a static hysteresis loop and hysteresis loss of the thin strip-shaped soft magnetic material by adopting an Energitic static hysteresis model; deducing an eddy current loss correction coefficient according to the magnetization rate expressions of the ascending branch and the descending branch; deducing a residual loss correction coefficient according to the magnetization rate expression; and calculating a dynamic loss parameter according to the sine loss density of the thin strip-shaped magnet material in one magnetization period under different frequencies and different peak magnetic densities. Based on the derived expression, a calculation process of the thin strip-shaped soft magnetic material high-frequency loss calculation method is established. The method can be used for accurately calculating the magnetic core loss of the high-frequency transformer in the full-bridge DCDC converter and the inductor in the Boost type DCDC converter, and effectively separating the components of the magnetic core loss.

Description

technical field [0001] The invention belongs to the design field of high-frequency transformers and inductors, and in particular relates to a calculation method for high-frequency loss of a magnetic core under symmetrical / asymmetrical rectangular voltage excitation. Background technique [0002] High frequency and high power have become the current development trend of DC-DC converters. With the increase of operating frequency and power and the reduction of the volume of magnetic components, the problem of magnetic core loss becomes more and more obvious, which reduces the efficiency. Therefore, it is necessary to reduce the core loss of the magnetic element to improve the overall working efficiency of the DC-DC converter. At present, most of the low-power magnetic components in inverters and switching power supplies use ferrite as the core. Ferrite has high resistivity and low high-frequency eddy current loss, but its saturation magnetic density is low, and its working ma...

AI Technical Summary

Problems solved by technology

The disadvantage of the Steinmetz empirical formula method and its modified formula is that it depends on the test. For a specific type of magnetic material, it is necessary to make a small magnetic ring of a specific size, measure the core loss density at different frequencies, and then obtain the undetermined Coefficient, the sample preparation process of the general ring sample test method at this stage is lengthy, and in practice the ring sample is far from the ideal situation

In addition, the empirical formula method can only obtain the total loss of the magnetic core, lacking a clear physical meaning

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