Drive circuit of power conversion device and power conversion device

Abstract

If a temperature difference occurs between the parallel-connected power semiconductor elements, the heat generation of the parallel-connected power semiconductor elements will become non-uniform, and reliability will decrease. A drive circuit of a power conversion device including a power conversion unit including an upper arm element (upper arm power semiconductor element) and a lower arm element (lower arm power semiconductor element) has a variable a voltage source; and a voltage control unit that changes a negative bias voltage generated by the variable voltage source in accordance with an output of a temperature detection unit shared by the upper arm element and the lower arm element. The positive side of the variable voltage source is connected to the high voltage side of the lower arm element. The low voltage side of the lower arm element is connected to one end of the capacitive element belonging to the lower arm. The other end of the capacitive element is connected to the anode terminal of the high withstand voltage diode. The cathode terminal of the high withstand voltage diode is connected to the negative side of the variable voltage source. If the lower arm element is turned on, charging current flows from the variable voltage source to the capacitive element.

Description

technical field [0001] The present invention generally relates to a power conversion device and a drive circuit thereof used for converting direct current to alternating current or converting alternating current to direct current. Background technique [0002] In recent years, there has been a demand for higher output density of an inverter device as an example of a power conversion device, and miniaturization and weight reduction of the power conversion device have been progressing. As the size of power conversion units (parts of power conversion devices) integrated with power semiconductor modules, capacitors, bus bars, etc. mounted with power semiconductor elements progresses in size, it is used to drive power semiconductor elements There is an increasing demand for downsizing and cost reduction of circuits. In addition, a power conversion device is realized by mounting a plurality of power conversion units integrated with power semiconductor modules, capacitors, bus bar...

AI Technical Summary

Problems solved by technology

Therefore, the performance of power semiconductor components cannot be fully utilized

[0004] As a conventional technology, power semiconductor elements are screened and power semiconductor elements with the same characteristics are combined together, but cost increases and restrictions on the number of parallel connections due to characteristic screening are problems.

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