Series formation constant-voltage charging circuit

Abstract

The invention discloses a series formation constant-voltage charging circuit. The circuit is used for charging a power battery pack, and the power battery pack is provided with a plurality of single batteries. The circuit comprises: a power supply module; a plurality of charging units which are connected in series with the positive pole and the negative pole of the power supply module, wherein each charging unit is provided with a main circuit MOS and a bypass MOS connected in parallel with the main circuit MOS, each main circuit MOS is provided with two main circuit diodes, the two main circuit diodes are in forward bias connection with the series formation constant voltage charging circuit, each bypass MOS is provided with two bypass diodes, and the two bypass diodes are reversely biased and connected in the series formation constant-voltage charging circuit; and a PWA drive which is used for controlling a main circuit diode and a bypass diode to connect or disconnect the series formation constant-voltage charging circuit.

Description

technical field [0001] The invention relates to the field of electric vehicle charging systems, in particular to a series-connected constant-voltage charging circuit. Background technique [0002] With the country building a low-carbon environment-friendly economy and the development of new energy strategies and the increasingly mature technology of electric vehicles, major cities are currently increasing the promotion and application of electric vehicles, and how to make electric vehicles can be conveniently and quickly charged has become It is a decisive and important link in its promotion and application. [0003] At present, the mainstream charging method in the charging pile market is constant current and constant voltage charging (CC-CV, constant current constant voltage), that is, stage 1 uses a larger current for constant current charging, and the battery voltage rises rapidly, and when it reaches the cut-off voltage, it is transferred to stage 2. Constant voltage c...

AI Technical Summary

Problems solved by technology

Then, if the above-mentioned constant current and constant voltage charging method is adopted at this time, the entire battery pack is subjected to constant current charging in stage 1 and constant voltage charging in stage 2. The state and performance decay are different, resulting in some single batteries with more than 85% power in stage 1, and some single batteries with less than 85% power. In stage 2, the time for each single battery current to reach the preset value is also different The same, so the above-mentioned overall constant current and constant voltage charging method cannot achieve the maximum charging efficiency of the battery pack, which greatly reduces the service life of the battery pack

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