Drive circuit of a power conversion device and power conversion device

Abstract

If the temperature difference of the power semiconductor elements connected in parallel is generated, the heating of the power semiconductor elements connected in parallel becomes uneven, and the reliability is reduced. A drive circuit of a power conversion device provided with a power conversion unit including an upper arm element (a power semiconductor element of an upper arm) and a lower arm element (a power semiconductor element of a lower arm) includes: a variable voltage source that generates a negative bias voltage of a gate of the upper arm element; and a voltage control unit that changes the negative bias voltage generated by the variable voltage source in accordance with the output of the temperature detection unit common to 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 capacitor element belonging to the lower arm. And the other end of the capacitor element is connected with the anode terminal of the high-voltage-withstanding diode. A cathode terminal of the high withstand voltage diode is connected to a negative side of the variable voltage source. If the lower arm element is turned on, the charging current flows from the variable voltage source to the capacitance element.

Description

Technical field [0001] The present invention generally relates to a power conversion device and its drive circuit used to convert direct current to alternating current or to convert alternating current to direct current. Background technique [0002] In recent years, an inverter device, which is an example of a power conversion device, has been required to increase its output density, and the size and weight of the power conversion device has advanced. The power conversion unit (part of the power conversion device) obtained by integrating power semiconductor modules with power semiconductor elements, capacitors, bus bars, and other components has been miniaturized and used to drive power semiconductor elements. The demand for the miniaturization and cost reduction of circuits has increased. In addition, the power conversion unit is realized by mounting multiple power conversion units that integrate power semiconductor modules, capacitors, bus bars, gate drive circuits, and other...

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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