Method for calculating optimal single-strand diameter and number of strands of square litz wire under non-sinusoidal current waveform excitation

Abstract

The invention provides a method for calculating the optimal single-strand diameter and the number of strands of a square litz wire under non-sinusoidal current waveform excitation. The method comprises the following steps: deducing a normalized thickness expression of a square litz line by adjusting the filling rate of each layer; deducing an alternating current resistance coefficient expression of the square Litz line under the nth harmonic frequency by combining a Down equation; mecanum series expansion is adopted, and the approximate expression of the Down formula of the square Litz line under the low-frequency condition can be obtained; deducing the loss of the square Litz wire under the excitation of the non-sinusoidal current; deducing a single-strand optimal diameter expression of the square litz wire. The litz wire needs to determine the optimal diameter of a single strand, and the number of strands of the litz wire needs to be calculated. The current carrying capacity of the Litz wire is related to the single-strand diameter and the number of strands. The method can be applied to the determination of the winding loss of the multi-turn square litz wire and the determinationof the optimal wire diameter of the square litz wire, can reduce the calculation amount and the calculation time, is convenient and fast, and is beneficial to engineering application.

Description

technical field [0001] The invention belongs to the design field of inductors and high-frequency transformers, in particular to a method for calculating the optimal single-strand diameter and strand number of a square litz wire under a non-sinusoidal current waveform. Background technique [0002] For multi-turn coils in inductors and high-frequency transformer equipment, due to the increase in driving frequency, flat copper wires and Litz wires are generally used as coil wires to reduce high-frequency losses caused by eddy current effects. When the carrying capacity of the winding is large and the frequency of the alternating current is high, the optimal thickness of the flat copper wire will be small and the width will be large, resulting in a high-frequency transformer core window height, which will cause difficulties in core processing and actual installation. ; If multi-strand and flat copper wires are used, although the height of the core window can be reduced, the pro...

AI Technical Summary

Problems solved by technology

Due to the large main insulation distance of the high-voltage large-capacity high-frequency transformer, there is an obvious transverse magnetic field component at the end of the winding, which reduces the accuracy of the analytical method

[0005] To sum up, it can be seen that the Litz wire reduces the proximity effect through the parallel transposition of different wires, and then makes the current distribution more uniform on the entire wire cross section, thereby reducing the loss, but the structure of the Litz wire is more complicated, and there is currently no accurate AC Loss Calculation Method for Square Litz Wire

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