Vehicle-mounted charger control circuit and method, charger and electric vehicle

Abstract

The invention provides a vehicle-mounted charger control circuit and method, a charger and an electric vehicle. The vehicle-mounted charger control circuit comprises a filtering and rectification module, a power factor correction module, a half-bridge LLC resonant conversion module and a main control module, wherein the filtering and rectification module is used for converting an input alternating-current electric signal into a direct-current signal after filtering out an electromagnetic interference signal; the half-bridge LLC resonant conversion module is used for enabling switching tubes tooperate in a zero-voltage state so as to realize zero-voltage switching when the charger is charged; and the main control module is used for acquiring a resonant current zero-crossing point of the half-bridge LLC resonant conversion module and a voltage zero-crossing point of mid-point voltage of the half-bridge LLC resonant conversion module in real time. By comparing the potential difference between the two zero-crossing points, resonant network input impedance of the half-bridge LLC resonant conversion module is detected to ensure that the half-bridge LLC resonant conversion module works in an inductive area, and it is ensured that the charger works in a zero-voltage working area no matter load changes or the input voltage changes, thereby reducing harmonic pollution during charging ofthe charger.

Description

technical field [0001] The present disclosure relates to the technical field of electric vehicles, in particular to a control circuit and method for a vehicle charger, a charger and an electric vehicle. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. [0003] Facing the addition of new energy, the safety and reliability of the power grid has been greatly tested, and strict requirements have been put forward for the safety and reliability of new energy joining the power grid, especially when the electric vehicle on-board charger is charging the electric vehicle, it is easy to generate Larger harmonic pollution, therefore, the resonant converter is generally used in the on-board charger to achieve zero-voltage startup and zero-current shutdown, but the general resonant converter has a phenomenon that the shutdown current is too large when the input...

AI Technical Summary

Problems solved by technology

[0003] Facing the addition of new energy, the safety and reliability of the power grid has been greatly tested, and strict requirements have been put forward for the safety and reliability of new energy joining the power grid, especially when the electric vehicle on-board charger is charging the electric vehicle, it is easy to generate Larger harmonic pollution, therefore, the resonant converter is generally used in the on-board charger to achieve zero-voltage start-up and zero-current shutdown, but the general resonant converter has a phenomenon that the shutdown current is too large when the input voltage is high. And there will be problems of high conduction loss and switching loss when the input voltage is wide, these limitations limit the further improvement of switching frequency and converter efficiency

[0004] The inventors of the present disclosure found in research that the half-bridge LLC resonant converter can realize ZVS in the full load range and wide input voltage range, which is very suitable as the power topology of the car charger. However, (1) the current common LLC resonant converter (2) The current LLC resonant converter cannot guarantee that the charger can work in the zero-voltage working area regardless of the load change or the input voltage change, so as to realize the new energy Electric vehicles can reduce harmonic pollution while charging with high efficiency in the grid; (3) The current LLC resonant converter cannot be adjusted in real time to ensure that the half-bridge LLC resonant conversion module works in the inductive region

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