High-power power electronic device applied to MMC and operation method thereof

Abstract

The invention provides a high-power power electronic device applied to an MMC and an operation method thereof. The power electronic device comprises an IGCT device and an IGBT device which are in parallel connection, and the IGCT device and the IGBT device have the equal voltage class and a certain current class proportion; furthermore, the IGCT device and the IGBT device can be sealed into a device tube shell with a special design, and therefore the stray inductance between the two devices is reduced. According to the high-power power electronic device applied to the MMC, the whole on-state voltage drop can be lowered, and the working efficiency of the MMC is improved; the loss is lowered, the size of the whole device is reduced, and the cost is lowered.

Description

technical field [0001] The invention belongs to the field of electric power technology and relates to power electronic devices, in particular to a high-power power electronic device applied to MMC. Background technique [0002] Modular multilevel converter (MMC for short) has many advantages such as very high conversion efficiency, extremely low output voltage harmonic content, small filter volume, modular characteristics, and easy installation and maintenance. It has gained widespread attention, making it very suitable for high-voltage and high-power electric energy conversion occasions. [0003] In practical applications, the key power components of the sub-modules of the MMC usually use insulated gate bipolar transistor (Insulated gate bipolar transistor, IGBT for short) devices. In the prior art, MMC based on IGBT devices has the following disadvantages: [0004] (1) The on-state voltage drop is high, resulting in large on-state losses; [0005] (2) After the modular ...

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Problems solved by technology

[0004] (1) The on-state voltage drop is high, resulting in large on-state losses;

[0005] (2) After the modular IGBT device fails, it is in an open circuit state. In the case of series redundancy, in order to ensure that other sub-modules still work normally, it is necessary to connect bidirectional thyristors and mechanical switches in parallel at both ends of the sub-module. complex;

[0006] (3) Although the crimp-type IGBT device is in a short-circuit state after failure, it cannot guarantee the reliability of long-term short-circuit failure, and the cost is too high

The reason is that the IGCT device is a current-mode device, the turn-on speed is fast and uncontrollable, and the high current change rate (di / dt) during the turn-on period of one IGCT will cause the reverse freewheeling diode connected in parallel with the other IGCT of the bridge arm to generate too high Therefore, it is generally necessary to set an anode reactance absorption circuit outside the IGCT device to reduce the current change rate (di / dt) of the turn-on and protect the diode, thus increasing the volume, increasing the cost and loss

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