Insulated gate bipolar translator (IGBT) clamping three-level frequency converter

Abstract

The invention relates to an insulated gate bipolar translator (IGBT) clamping three-level frequency converter, and belongs to the field of frequency converters. A main circuit of the IGBT clamping three-level frequency converter is a three-phase six-bridge arm frequency converting circuit; each of a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a fifth bridge arm and a sixth bridge arm comprises three switching elements, wherein the first bridge arm and the second bridge arm are connected with a phase W of an output circuit; the third bridge arm and the fourth bridge arm are connected with a phase V of the output circuit; the fifth bridge arm and the sixth bridge arm are connected with a phase U of the output circuit; and each of the phase W, the phase V and the phase U is provided with six free-wheeling diodes and two series energy storage capacitors. By clamping connection and disconnection of an IGBT, the frequency converter solves the problem that the waveform quality of the output voltage is affected by unequal upper and lower capacitor voltages and midpoint potential drift when a certain phase of output voltage in three phases of output voltages is zero, current flows into or flows out of a direct-current capacitor midpoint and the inflow current is unequal to the outflow current.

Description

technical field [0001] The invention relates to a frequency converter, in particular to an IGBT clamped three-level frequency converter. Background technique [0002] The AC-DC-AC frequency converter widely used in my country's industrial system, the core of its inverter system is IGBT. Due to the limitation of power electronic device technology, the withstand voltage level of the device is limited. The relatively mature high-voltage IGBT can only reach 3300V, and the IGBT with a withstand voltage of 6500V has not yet been officially commercialized. High-voltage and high-current devices are generally expensive, and often withstand a higher level of voltage, and the price has doubled, greatly increasing the cost of the device. In medium and high voltage high power applications. Considering the withstand voltage, current and cost of the device, in order to obtain high-voltage power conversion, the traditional inverter can only be realized by the series-parallel connection of...

AI Technical Summary

Problems solved by technology

While obtaining high-voltage input and output characteristics, the multi-level inverter also reduces the high-voltage stress on the device, and can use devices with lower voltage levels to construct a high-voltage converter, which solves the problems caused by the series and parallel connection of devices and reduces the system cost. comprehensive cost of

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