SCDAB-CLLLC composite direct-current transformer with wide voltage regulation range and control method thereof

Abstract

The invention provides an SCDAB-CLLLC composite direct-current transformer with a wide voltage regulation range and a control method thereof. A main circuit comprises a switched capacitor type bidirectional full-bridge DC / DC converter and a CLLLC type resonant converter which are cascaded in an input-series output-parallel manner, so the requirement on the transformation ratio of a high-frequency transformer is reduced, the voltage and current stress of an input side power device is reduced, and the voltage regulation range is wide. The controller takes a DSP as a core device and has the functions of overvoltage and overcurrent protection, phase shift control and frequency modulation control; the phase shift control is applied to the switched capacitor type bidirectional full-bridge DC / DC converter, and the frequency modulation control is applied to the CLLLC type resonant converter.

Description

technical field [0001] The invention relates to the field of power conversion of medium and low-voltage DC distribution networks in power electronics, in particular to a SCDAB-CLLLC composite DC transformer with a wide voltage regulation range and a control method thereof. Background technique [0002] In response to the huge challenges brought about by global climate change and the dwindling fossil energy reserves, the development of new energy power generation has become the main trend of world energy development. The proportion of new energy power generation in the total power generation and the number of new energy installed capacity are continuously increasing. . Compared with traditional thermal power generation and nuclear power generation, new energy power generation fluctuates greatly randomly, and the power generation is easily affected by environmental factors such as temperature and light. When a large amount of new energy power generation is connected to the AC...

AI Technical Summary

Problems solved by technology

[0006] In view of the high voltage gain and ZVS in the current DC transformer topology that needs to meet the requirements of high power and high voltage gain at the same time, ZCS soft switching characteristics take into account the difficulty of design, the DC capacitance value of the low voltage side and the resonance current, and the high voltage. Due to the difficulty of current high-frequency resonant capacitor selection and other factors, the present invention provides a SCDAB-CLLLC composite DC transformer with a wide voltage regulation range and its control method. This topology has a wider voltage regulation range and a higher Strong soft switching capability can effectively reduce the voltage and current stress of a single module and improve the overall controllability of the system, which is of great significance for improving the output power quality of DC transformers

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