Three-level indirect matrix converter and control method

Abstract

The invention provides a three-level indirect matrix converter and a control method. The three-level indirect matrix converter comprises an input voltage selector, an active triple-harmonic injection circuit and an inverter, wherein the input end of the input voltage selector is connected with a three-phase alternating current power supply, and the output end of the input voltage selector is connected with positive and negative electrode direct current buses; the upper and lower ends of the active triple-harmonic injection circuit are connected with the positive and negative electrode direct current buses respectively, and a third end of the active triple-harmonic injection circuit is connected with the input end of the input voltage selector and the output end of the inverter; the upper and lower ends of the inverters are connected with the positive and negative electrode direct current buses respectively, and the output end is connected with a load. Triple harmonic injection induction currents are generated through the active triple-harmonic injection circuit and injected into the input voltage selector and the inverter respectively, so that the average current of the neutral point is kept to be zero, self-balance of voltage of the neutral point is further guaranteed, and the quality of input and output waveforms is improved.

Description

technical field [0001] The present invention relates to the technical field of power conversion, and more specifically, to a three-level indirect matrix converter and a control method. Background technique [0002] With the rapid development of power electronics technology, the power electronics industry's requirements for voltage frequency and amplitude have become more diverse. Therefore, it has become an urgent need to convert the power supply voltage into a voltage with the frequency and amplitude required by the load to meet the diverse needs of the power electronics industry for voltage. [0003] In the prior art, a matrix converter is mainly used to directly convert the power supply voltage into the voltage required by the load. Among them, the center point clamped matrix converter (NPC MC) is widely used in many occasions because of its ability to generate multi-level output voltages, high conversion efficiency, compact structure and simple clamping circuit. [000...

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a three-level indirect matrix converter and a control method to overcome that in the prior art, when NPC MC is in normal operation, it is difficult to achieve a zero-average neutral point to maintain the balance of the neutral point potential. The input power control range is limited and the modulation of the rectifier and inverter stages needs to be strictly synchronized

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