Charging module, DC charging pile and control method for DC charging pile

Abstract

The invention provides a charging module, a DC charging pile and a control method for the DC charging pile. The charging module includes a rectification module, an LLC resonance module and a chopping module; wherein, the rectification module is used to control the input DC voltage of the LLC resonance module to be stable, and the LLC The resonant module adopts a fixed switching frequency control method. Therefore, the output voltage of the LLC resonant module is fixed or has a small variation range, which optimizes the resonant inductor and transformer in the LLC resonant module, thereby reducing the design of the resonant inductor and transformer in the LLC resonant circuit. difficulty. And the chopper module is used to adjust the output voltage range of the LLC resonant module, and finally the output voltage range of the charging module is wider. Since the LLC resonant module is controlled by an open-loop control mode with a fixed switching frequency, the fixed switching frequency can be set near the resonant frequency of the LLC resonant module, thereby improving the conversion efficiency of the LLC resonant module.

Description

technical field [0001] The invention belongs to the technical field of power supplies, and in particular relates to a charging module, a DC charging pile and a control method for the DC charging pile. Background technique [0002] DC charging pile is currently the preferred method for fast charging of electric vehicles. A DC charging pile can be composed of one or more charging modules. Among them, the greater the power of the DC charging pile, the more charging modules are required. For example, a 120kW DC charging pile can be composed of six 20kW charging piles connected in parallel. [0003] At present, the charging module in the DC charging pile usually adopts a two-stage high-frequency isolation topology. Common charging module topologies include: pre-stage VIENNA rectifier + post-stage phase-shifting full bridge, pre-stage VIENNA rectifier + post-stage LLC full-bridge resonant conversion Circuit, pre-stage VIENNA rectifier + post-stage LLC half-bridge resonant convers...

AI Technical Summary

Problems solved by technology

[0004] In view of this, the object of the present invention is to provide a charging module, a DC charging pile, and a control method for a DC charging pile, so as to solve the problem that the charging module based on LLC is difficult to design a resonant inductance and a transformer, and it is difficult to achieve wide input and wide output regulation. , wherein the specific technical scheme is as follows:

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