High-frequency isolated three-phase cycloconverter type two-way converter and control method thereof

Abstract

The invention provides a high-frequency isolated three-phase cycloconverter type two-way converter and a control method thereof, which belongs to the three-phase high-frequency isolated converter in the field of power electronics and is suitable for charging and discharging a storage battery pack, a supercapcitor set and other energy storage devices. A main circuit is in a structure comprising an input filter, a three-phase cycloconverter, a high-frequency transformer, a full-bridge converter and an output direct current inductor, wherein a switch of the cycloconverter is in time-division drive to ensure the one-way flowing of the power and further realize the soft current conversion. The switching of two modes of rectification and inversion can be realized by changing the power flowing direction of the cycloconverter; the three-phase cycloconverter is modulated by digitalized alternating current space vector; and the alternating current adopts a control method of mixing a d-p decoupling, the proportional-integral (PI) and the repetition (RP). The two-way converter has the advantages of high power density, high efficiency, wide adjusting range of direct current side voltage and electrical isolation for input and output; and the input of unit power factors can be realized and the current harmonics can be effectively inhibited.

Description

technical field [0001] The invention provides a high-frequency isolated three-phase cycloconverter type bidirectional converter and a control method thereof. It belongs to the direction of three-phase high-frequency isolated converters in the field of power electronics. Background technique [0002] With the development of power electronics technology, energy storage systems are gradually being used in various fields, including valley-peak regulation of power grids, power storage of electric vehicles, etc. The key equipment in the energy storage system is a bidirectional converter, which connects the grid and the energy storage device through the bidirectional converter, which can not only inject the energy of the grid into the energy storage device, but also feed back the energy in the energy storage device to the grid. At present, the widely used energy storage devices such as battery packs and supercapacitor packs have very low terminal voltages and need to be boosted be...

AI Technical Summary

Problems solved by technology

Transformation of the power frequency transformer increases the weight and volume of the converter again, and greatly increases the cost of the converter. The noise pollution of the power frequency transformer cannot be ignored

IEEE Trans.on Power Electronics [Journal of Power Electronics] published the article "Three-Phase Boost-Type Grid-Connected Inverter" [Three-Phase Boost-Type Grid-Connected Inverter] in the fifth issue of 2008, using the boost inverter topology, which constitutes a step-up inverter, which increases the conversion range of the DC side voltage, and adopts the method of IGBT series diodes, which cannot realize bidirectional flow of power

The analog control method based on the single-cycle control strategy cannot eliminate the reactive current component brought by the filter capacitor, and the analog controller has limited ability to suppress the harmonics of the current

Images