Low voltage DC side topology with switchable AC and DC capacity of power electronic transformer

Abstract

The invention belongs to the technical field of power electronics and especially relates to a low voltage DC side topology with switchable power electronic transformer AC and DC capacities. The low voltage DC side topology comprises an energy storage converter module, switchable half bridge modules, an inverter module, an AC and DC switching module and a common AC filter. A power electronic transformer low voltage DC side is provided with an AC port and an electric vehicle charging and discharging ports. Through the cooperation of multiple switchable half bridge modules on a low voltage DC and the AC and DC switching module, the switching between an AC capacity and an electric vehicle DC charging capacity is realized. According to AC load and charging electric vehicle number, the number of the switchable half bridge modules working at an AC or DC mode is determined, and the utilization rate of the power electronic transformer is optimized. The low voltage DC side topology has the ability to supply power to a grid from an electric vehicle reversely, the grid stability can be enhanced, the reliability of load power supply is guaranteed, and the energy storage configuration capacity is reduced.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a low-voltage DC side topology with switchable AC and DC capacity of a power electronic transformer. Background technique [0002] A power electronic transformer is a power electronic device with functions such as voltage conversion, reactive power compensation, unbalance control, and power quality management. Power electronic transformers mainly include three parts: high voltage side, intermediate stage and low voltage side. The high-voltage side is responsible for converting high-voltage power frequency AC into high-voltage high-frequency AC, the intermediate stage is responsible for voltage conversion, and the low-voltage side is responsible for converting low-voltage high-frequency AC into low-voltage power frequency AC. Among them, the low-voltage side often adopts AC / DC / AC structure, and the high-frequency AC is first rectified and filtered to DC and ...

AI Technical Summary

Problems solved by technology

[0007] The traditional power electronic transformer topology does not have DC charging and discharging ports for electric vehicles, and there is no technology for switching between DC capacity and AC capacity. The application of electronic transformers and the development of electric vehicles are of great significance

Images