Multi-module parallel output current-sharing current transformer

Abstract

The invention discloses a multi-module parallel output current-sharing current transformer. The multi-module parallel output current-sharing current transformer comprises a rectification module, a first inversion module and a second inversion module which are successively arranged. The input of the current transformer is three-phase AC power which, through the rectification module, is converted into DC power as the input of the first inversion module and the second inversion module; four branches of the first inversion module and four branches of the second inversion module are connected in parallel between a positive busbar and a negative busbar of a DC side; output signals of the first inversion module and the second inversion module are used for supplying power to a traction motor to drive the traction motor to run; and when the traction motor stops running, a brake resistor starts working to consume voltage on the positive busbar and the negative busbar at the DC side of the current transformer, such that personal safety is guaranteed. The multi-module parallel output current-sharing current transformer brought forward by the invention is small in technical difficulty, low in investment cost and good in current sharing effect, perfectly solves the parallel output current sharing problem, reduces the production cost and the technical difficulty of the current transformer and enables batch production of a large-power current transformer to be possible.

Description

technical field [0001] The invention relates to the technical field of converter circuits, in particular to a multi-module parallel output current equalizing converter. Background technique [0002] As the market demand for high-power power electronic devices continues to increase, the power output of single-branch devices is gradually unable to meet the industry's demand for high power. Usually, multiple power electronic devices (such as IGBTs) are connected in parallel to form a power module with higher current density to increase the power level of the power electronic device. However, in the parallel connection of multiple devices, the problem of output current sharing has always been a technical problem, which hinders the development of converters to higher power levels. [0003] The following are several existing current sharing methods: [0004] 1) Encapsulate the current equalizing device of the entire variable current output on the same copper plate, and realize t...

AI Technical Summary

Problems solved by technology

However, in the parallel connection of multiple devices, the problem of output current sharing has always been a technical problem, which hinders the development of converters to higher power levels.

[0004] 1) Encapsulate the current equalizing device of the entire variable current output on the same copper plate, and realize the current equalizing of multiple branches through symmetrical design, the same size and the same impedance; but since all the current equalizing devices are concentrated on one copper plate , the size of the equipment is not easy to increase, it can only increase the power density, but it cannot meet the industrial demand for high-power converters;

[0005] 2) The current unbalance is suppressed by connecting the intersecting current limiting loops in series at the output end, so as to achieve the purpose of static current sharing at the output end; the unbalanced current is suppressed by adding a current loop, but the addition of the current loop undoubtedly increases the equipment cost, and also increases the possibility of failure

If the current sharing problem is not well solved, it is almost impossible to realize the mass production of multi-module parallel connection of converters, and the so-called theoretical research will become worthless

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