power conversion device

Abstract

The invention provides an electric power conversion device which has a buffer module, does not need to arrange space for a buffer in front of a terminal of a power semiconductor module, and can reduce mechanical stress of the terminal of the power semiconductor module. According to the electric power conversion device, power semiconductor modules are mounted respectively on two opposite faces of a heated block of a heat tube type cooling body, a positive electrode and a negative electrode of each power semiconductor module are connected with a smoothing capacitor via a bus, the electric power conversion device has a buffer module, the buffer module is internally provided with a buffer which suppresses overshoot voltage in switching-on and switching-off of the power semiconductor modules, a plurality of terminals protrude, the buffer module is configured under the heated block, and the terminals are jointed to the buses respectively.

Description

technical field [0001] The present invention relates to a power conversion device composed of a rectifier (converter), a smoothing capacitor (smoothing capacitor) and an inverter (inverter). Background technique [0002] A general power conversion device consists of the following components: a rectifier (converter) that converts AC power to DC; a smoothing capacitor that smoothes the output of the rectifier; and an inverter (inverter) that converts DC to variable voltage and variable frequency. . The main circuit wiring connecting the rectifier and the inverter employs bus-bar wiring to reduce the inductance of the wiring, and a smoothing capacitor is connected in the middle of the bus-bar wiring. [0003] When the inductance of the bus wiring is large because the amount of current flowing through the wiring between the smoothing capacitor and the inverter is large, the overshoot voltage increases when the inverter performs switching operations. As this overshoot voltage i...

AI Technical Summary

Problems solved by technology

[0006] However, even if the wiring between the power semiconductor module and the smoothing capacitor is set to the shortest distance, the number of smoothing capacitors increases according to the amount of current flowing, and the distance between the power semiconductor module and the increased amount of smoothing capacitors becomes longer, Therefore, in a power conversion device with a large amount of current, a snubber is required anyway

The buffer is usually directly connected to the terminal of the power semiconductor module, but a space for installing the buffer is required in front of the terminal

In addition, when the size of the buffer increases, the mass also increases, and when mechanical stress (mechanical stress) is applied to the terminals of the power semiconductor module due to vibration during transportation, etc., the power semiconductor module may fail.

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