Finite element simulation-based current sharing optimization design method for multiple parallel switching devices

Abstract

The invention relates to a parallel current sharing problem of a multi-device high-power MOS (Metal Oxide Semiconductor) tube, and provides a finite element simulation-based current sharing optimization design method for multiple parallel switching devices. The multi-parallel switching device comprises a driving module, a first switching tube device, a second switching tube device,..., and an nth switching tube device. The method comprises steps of manually setting the length of a wire between the driving module and the switching devices, and designing a circuit board through Altium Designer software according to a structural symmetry principle among the first switching tube device, the second switching tube device,..., and the nth switching tube device; determining an optimized target parasitic inductance value; setting a required error; and calculating the width of the routing between the initialized driving module and the switching device in combination with the target parasitic inductance value, and optimizing the width of the routing between the driving module and the switching device through finite element simulation multiple iterations. According to the method, the obtained simulation parasitic parameters are high in accuracy, and the parasitic parameters are effectively reduced; the parallel non-uniform current is effectively reduced, and the system stability is improved.

Description

technical field [0001] The invention relates to the field of multi-switch device parallel current sharing design, in particular to a multi-parallel switch device current sharing optimization design method based on finite element simulation. Background technique [0002] In recent years, with the rapid development of power electronics technology, the requirements for power devices have become higher and higher. Compared with traditional Si MOSFETs, SiC MOSFETs have higher switching speeds, lower on-state losses and higher blocking voltages. And many other advantages, it can improve the system efficiency, reduce the volume of the equipment and improve the power density of the equipment. However, due to the current technology level and the limitation of cost under specific requirements, the flow capacity of a single SiC MOSFET is limited and cannot meet the requirements of high-power applications. It is often necessary to use multiple SiC MOSFETs in parallel. This parallel appl...

AI Technical Summary

Problems solved by technology

Among them, the drive circuit plays a vital role in the dynamic current sharing of parallel devices. The gate drive resistance and parasitic inductance in the drive circuit will affect the inconsistency of the drive signals between the branches, which will cause the switch tube that is turned on first to withstand overcurrent. possible damage to the switch tube

The conventional design scheme requires that the driving circuit and the main circuit of each switching tube be arranged in strict symmetry / equal length. The structure of each parallel switch tube is symmetrical. On the basis of the symmetry of the main power circuit of the switch tube, it is difficult to achieve a symmetrical structure for the drive circuit of each parallel switch tube, which brings design difficulties to the parallel connection of multiple tubes.

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