A transformer-isolated three-module ac-ac matrix converter and its modulation method

Abstract

The invention discloses a transformer-isolated three-module AC-AC matrix converter and a modulation method thereof, and relates to the technical field of power electronic power converter modulation control. A transformer-isolated three-module AC-AC matrix converter, the sub-modules adopt Three-phase AC / single-phase AC matrix transformation topology, three sub-modules work together. Based on this topology, a voltage-type SVM space vector combinatorial logic modulation method is proposed. The polarity selection signal decomposes the logic of the bidirectional switching tube into a unidirectional controllable switching tube, and then each module is logically decomposed into two groups of positive and negative three-phase / single-phase full-bridge circuits. The 6-sector voltage-type SVM modulation signal is used as the basic modulation signal, and the combined logic operation is performed with the polarity selection signal with a phase difference of 120° to obtain the driving signals of each unidirectional switch tube. The invention has the advantages of safe use, high output voltage, flexible control of bidirectional switching tubes, strong load adaptability, low switching frequency, and flexible bidirectional flow of energy.

Description

technical field [0001] The invention relates to the technical field of power electronic power converter modulation control, in particular to a transformer-isolated three-module AC-AC matrix converter and a modulation method thereof. Background technique [0002] A converter is a topological device that converts alternating current energy of a certain amplitude and frequency into electrical energy of different amplitude and frequency. The matrix converter is called a "universal converter", which can theoretically directly realize the same or different numbers of input and output phases. Among them, matrix converters that input three-phase voltage and output three-phase voltage are more commonly used. The topology used in a transformer-isolated three-module AC-AC matrix converter is also called a three-phase-three-phase matrix converter, which can directly realize a certain The function of three-phase input of one amplitude frequency to another three-phase output of amplitude...

AI Technical Summary

Problems solved by technology

[0003] There is a coupling relationship between the loads of the traditional three-phase matrix converter, and the loads cannot be independent

In the case of large voltage output, the terminal voltage of the switch tube is high, which threatens the safety of the equipment

Moreover, the number of switches in the AC-AC matrix converter is large, and the bidirectional switch tubes are connected back-to-back, so most of the modulation strategies are difficult to implement and the commutation strategies are complicated, which makes it difficult to realize the conversion form of input three-phase voltage and output three-phase voltage

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