Bypass circuit

Abstract

The invention provides a bypass circuit, which is connected in parallel at the alternating current output side of each cascade connection module; the bypass circuit comprises a group of full control type switching tubes, and is provided with a driving circuit. The bypass circuit has the advantages that the work is reliable; the bypass switching is fast; the size is small; the power consumption is low.

Description

technical field [0001] The invention relates to the technical field of power module cascading, in particular to a bypass circuit. Background technique [0002] In the application where the modules are cascaded to output AC high voltage, in order to ensure the normal operation of the system, the cascaded modules (also called inverter bridges) are generally connected in parallel with bypass circuits. When a module fails, the bypass circuit is used to bypass the faulty module to ensure that other power modules continue to work normally, so that the system operation will not be affected. [0003] Existing bypass circuits for cascaded modules mainly use thyristors or mechanical switches (contactors or relays) to achieve bypass. Such as figure 1 As shown, the bypass circuit adopts the thyristor anti-parallel method. Specifically, the bypass circuit is composed of an AC filter circuit 2 and a thyristor circuit 3 . Wherein the AC filter circuit 2 includes an AC filter inductor L...

AI Technical Summary

Problems solved by technology

However, when the value of the capacitor C increases, the loss consumed on the resistor R increases, which reduces the efficiency of the system; when the value of the inductor L increases, the volume of the power module increases

In addition, the introduction of LC will cause the output waveform of the power module to oscillate, and will form a voltage spike between the cathode and anode of the thyristor. Therefore, the above bypass scheme puts forward higher requirements on the withstand voltage capability of the thyristor.

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