A hybrid DC converter

Abstract

The invention discloses a hybrid DC converter, which is composed of a high-frequency resonant converter and a double active bridge converter connected in parallel. The converter includes a full-bridge inverter A, a high-frequency transformer and an uncontrolled rectifier bridge; the full-bridge inverter A and the uncontrolled rectifier bridge are respectively connected to both ends of the high-frequency transformer; The inverter includes a full-bridge inverter B, an intermediate frequency transformer and a fully-controlled rectifier bridge; the full-bridge inverter B and the fully-controlled rectifier bridge are respectively connected to the first and last ends of the intermediate-frequency transformer. The present invention combines the advantages of the high-frequency resonant converter and the dual active bridge DC converter, and considers the current capability of the high-frequency resonant capacitor. The dual active bridge DC converter ensures the stability of the terminal voltage and the power transmission capability. The converter adopts a closed-loop PI control strategy as a whole.

Description

technical field [0001] The invention relates to a DC converter, in particular to a hybrid DC converter. Background technique [0002] With the increasing speed of social development, human demand for energy continues to increase, and the contradiction between the depletion of fossil energy and the high demand for energy in social development forces people to pay more and more attention to the development and utilization of renewable energy. It is an important way to realize "clean replacement" and "electric energy replacement" by utilizing scattered renewable energy such as wind energy, solar energy, ocean energy, etc., and developing distributed generation (Distributed Generation, DG) according to local conditions. At the same time, China's photovoltaic power generation capacity will reach 4GW. However, limited by the capacity of the power system, most renewable energy has not been effectively utilized, and even the phenomenon of "abandoning wind" and "abandoning light" ha...

AI Technical Summary

Problems solved by technology

The soft-switching characteristics of the phase-shifted full-bridge converter are poor, and it is difficult to ensure the overall efficiency of the converter

The LLC type resonant converter can guarantee soft switching characteristics in the full load range and has constant voltage regulation capability, but in the case of high frequency, the power transmission is limited by the current capacity of the resonant capacitor

The power transmission of the DAB converter depends on the stable terminal voltage, so the control link of this type of converter is often very complicated

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