A high-power high-transformation-ratio resonant DC power supply and its working method

Abstract

The invention discloses a high-power high-ratio resonant DC power supply and a working method thereof. The power supply comprises an intermediate frequency transformer, a primary side circuit connected to a primary winding of the intermediate frequency transformer, and a secondary side full-bridge uncontrolled rectifier circuit connected to a secondary winding of the intermediate frequency transformer. The primary circuit combines a single-phase MMC topology with a resonant converter and converts medium-voltage direct current into medium-voltage intermediate frequency alternating current. Through a modular multi-level mode, the voltage and current stress of a device are reduced, the selection range of the device is increased, the high frequency of a system is realized, and the power density is raised. At the same time, the topology and a LLC resonant network are combined, the soft switching technology is introduced, the working range of the system is increased, and the working efficiency of the system is improved.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a high-power high-transformation-ratio resonant DC power supply and a working method thereof. Background technique [0002] In recent years, the demand for energy has increased day by day along with economic growth, and environmental issues have become the number one challenge for human survival and development. Therefore, it is imperative to transform the energy structure from relying on fossil energy to clean new energy, which further accelerates the development and utilization of renewable energy. With the development of new energy represented by wind power and photovoltaics, the large-scale grid connection and transmission of new energy poses great challenges to traditional power grids. In this case, the DC distribution network has higher flexibility, reliability and economy, and has independent power regulation capabilities, and has become an efficient...

AI Technical Summary

Problems solved by technology

However, such a solution still has many deficiencies

First of all, in order to ensure the reliability of the system, it is necessary to ensure the redundant backup of the system, and the module cost of the system under this scheme is relatively high, so the difficulty of backup is increased

Secondly, each module contains magnetic components with large volume and weight. At the same time, in order to ensure a high insulation level of the system, a large module spacing is required, which greatly limits the improvement of system power density.

At the same time, in terms of control: the voltage equalization problem at the input end of the module, the current equalization problem at the output side, and the response speed problem on the control all greatly limit the further optimization and development of this solution.

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