Feedback control circuit for staged charging of vehicle-mounted charger and implementation method

Abstract

The invention provides a feedback control circuit for staged charging of a vehicle-mounted charger and an implementation method. Voltage loop and current loop double closed-loop control is adopted, aresistance voltage-dividing network is connected with a battery pack in parallel, sampling of the charger is performed and a sampling value is inputted into a constant-voltage control loop or a constant-current control loop; the MCU is connected with the constant-voltage control loop and the constant-current control loop and outputs two paths of duty ratios, only a constant-voltage control or constant-current control working mode is adopted at the same time, and only feedback signals of voltage feedback or current feedback are outputted through the OUT end. The charging process is enabled to follow the 'Mass curve' of the battery pack so that the charging efficiency is improved, the service life of the battery pack is protected, adjustment is made according to different vehicle-mounted charging environments, complex operation of the user is not needed, and the flexibility and the convenience of the vehicle-mounted charger of the electric vehicle are improved.

Description

technical field [0001] The invention relates to the field of power electronic power conversion, in particular to a control circuit for a charging process, which is mainly used to realize staged charging of a vehicle-mounted charger. Background technique [0002] With the continuous development of electric vehicles, the charging and discharging of power battery packs has become a bottleneck restricting its breakthrough. The electric vehicle charger can convert the mains power into the electric energy required by the electric vehicle, which improves the convenience of people's travel. At present, the charging methods used by electric vehicle chargers mainly include: constant current charging method, constant voltage charging method, staged (two-stage or three-stage) charging method. The constant current charging method is to keep the charging current constant during the charging process of the lithium battery, and the charging voltage continues to increase. If the charging c...

AI Technical Summary

Problems solved by technology

Aiming at the charging problem of vehicle-mounted chargers, the present invention proposes a feedback control loop for completing staged charging in order to avoid the overcharging phenomenon before and after charging by constant voltage charging method and constant current charging method, and also solves the problem of traditional staged charging at the same time. The problem that the voltage reference value and current reference value of the charging control circuit are fixed

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