igbt module parallel structure and power module structure

Abstract

An embodiment of the present invention provides an IGBT module parallel structure and a power module structure, wherein the IGBT module parallel structure includes: n IGBT modules, AC output parallel copper bars, AC output connecting copper bars, and AC output copper bars, wherein n ≥2, n IGBT modules are connected in parallel by using AC output parallel copper bars, one end of the AC output connection copper bar is connected to one end of the AC output parallel copper bar, and the other end of the AC output connection copper bar is connected to the AC output copper bar. The other end of the AC output connection copper bar connected to the AC output copper bar is vertically higher than one end of the AC output connection copper bar connected to the AC output parallel copper bar. The invention can reduce the non-uniform flow of the parallel IGBT, thereby effectively improving the power density of the overall parallel power module, reducing the failure rate, without adding other components, simple structure, low cost, and easy installation and maintenance.

Description

technical field [0001] The invention relates to the technical field of IGBT module parallel connection design, in particular to an IGBT module parallel connection structure and a power module structure. Background technique [0002] With the improvement of the power level of power electronic equipment, the demand for parallel assembly of multiple IGBT modules into high-power equivalent modules is increasing day by day. figure 1 A circuit schematic diagram using a general method for IGBT parallel connection in the prior art, such as figure 1 As shown, two switching elements in each vertical column correspond to one IGBT module in the engineering structure, and three IGBT modules are connected in parallel. [0003] In order to ensure the current sharing degree of the parallel IGBT modules, a symmetrical AC output mode can be adopted, that is, the AC output terminal (AC) is kept at the symmetrical output position of all parallel IGBT modules. figure 2 It is a schematic diagr...

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Problems solved by technology

figure 2 It is a schematic diagram of the current sharing effect of the parallel structure using the symmetrical AC output mode in the prior art, such as figure 2 As shown, the number of IGBT modules connected in parallel is 3, and the difference between the maximum and minimum current values ​​is about 300A. The uneven flow rate of each IGBT module reaches 20%, and the current sharing effect is not ideal.

However, the current domestic patent CN103595222A discloses a parallel structure of IGBT modules and its current sharing method. This technical solution is based on the symmetrical AC output mode, and achieves the purpose of current sharing by adding auxiliary components (current limiting ring), but this The method is difficult to implement, and the design and installation of multiple IGBT modules in parallel are more complicated. For example, when the current flowing through a single IGBT module reaches more than 1000A, the volume of the current limiting ring will be very large. When the wire is large, it will bring a large stray inductance, which directly affects the current sharing effect and the IGBT turn-off overvoltage

[0004] In addition, an asymmetrical AC output method can also be used, that is, the AC output terminal (AC) can be kept at the leftmost or rightmost end of all parallel IGBT modules, but in the actual engineering structure using this method, the AC output connection copper bar is related to If the horizontal direction is parallel, the current balance flowing through the parallel IGBT cannot be guaranteed

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