Nine switch tube five level active neutral point clamp dual active bridge isolated dc-dc converter

Abstract

The invention belongs to the field of DC-DC converters, and relates to a nine-switch tube five-level active neutral point clamping dual active bridge isolation DC-DC converter, the main circuit of which is equipped with active devices on the primary side and the secondary side of the transformer. Bridge, at least one active bridge includes a nine-switch tube 5L-ANPC bridge arm circuit; the bridge arm circuit is obtained by connecting the ninth switch tube in series on the flying capacitor branch on the basis of the traditional 5L-ANPC. The flying capacitor voltage balance control unit controls the switches in each bridge arm circuit by driving the waveform generator to control the bridge arm circuit to output zero-level and non-zero-level states, wherein the zero-level state ensures that the nine switch tubes are in the During the dead time switching between every two adjacent 1 / 2 switching cycles, it is avoided to be in the off state. The above-mentioned balance control unit has two modulation modes, and can also perform the flying capacitor voltage balance control based on hysteresis control and variable duty ratio control. The converter of the invention has good soft switching characteristics and loss distribution characteristics, and can be adapted to high-voltage and high-power application occasions.

Description

technical field [0001] The invention belongs to the field of DC-DC converters, and more specifically relates to a nine-switch tube five-level active neutral-point clamping dual active bridge isolation DC-DC converter. Background technique [0002] Dual active bridge (DAB) isolated DC-DC converter is one of the preferred circuits for building DC transformers. The traditional double active bridge (DAB) isolated DC-DC converter adopts the bridge arm structure mostly as the H-bridge circuit converter. This converter has the characteristics of high reliability, simple structure, and fewer switches, but the voltage stress on each switch is the DC bus voltage. Limited by the withstand voltage rating of the switching tube, it is difficult to realize the application of the bidirectional DC-DC converter with this structure under high voltage conditions. At the same time, the high withstand voltage switching tube has the problems of large switching loss and low switching frequency, w...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a nine-switch tube five-level active neutral-point clamping dual active bridge isolation DC-DC converter, which is used to solve the problem that the existing dual active bridge isolation DC-DC converters are adjacent to each other when they are working. Technical problem with limited application due to dead-zone effect in dead-time at both half-cycles

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