Serial and parallel switching and charging method and charging device for lithium dynamic battery unit

Abstract

The invention discloses an Li traction battery series parallel change-over charging method and a charging device. The charging device comprises a power main loop comprising a rectifier circuit, a DC filtering capacitor, a pre-charging circuit, a voltage sensor, a switch bridge circuit, a charging current sensor and a series parallel change-over switch, a control circuit board comprising a parallel branch signal unit, a switch signal drive control unit, a coil signal circuit, a voltage current signal circuit, a control processor and a signal display unit, a serial charging circuit comprising a filter inductor, a filter capacitor and an output voltage sensor, and a parallel charging circuit comprising a primary coil, a feedback coil, an iron core, a plurality of secondary coils of a multi-winding transformer and a plurality of series parallel charging unit. The pre-charging, serial charging and parallel charging are carried out by the charging method according to a set pre-charging voltage value and an end voltage value. The method and the device provided by the invention reduce the cost and volume of charging devices, maintain the balance of charging capacity of every Li traction battery electrical core, ensure adequate protection and best working status for each battery unit and improve safety and service life cycle of Li traction battery.

Description

1. Technical field [0001] The invention relates to a charging method and a charging device for a lithium power battery pack in the field of electric vehicles including hybrid vehicles. 2. Background technology [0002] Lithium-ion battery packs have attracted close attention in the field of electric vehicles including hybrid vehicles due to their high energy density, high specific power, and long cycle life. More and more electric vehicles begin to use lithium power batteries as power sources. In particular, lithium-ion and lithium-polymer batteries are widely used because of their light weight, large capacity, and low internal resistance. However, it is easy to be damaged. If it does not follow its charging characteristics, the number of charging times will be greatly reduced, which will greatly reduce its service life. Therefore, how to charge the lithium power battery pack is an important issue to be solved at present. [0003] The breakdown voltage of the electrolyte o...

AI Technical Summary

Problems solved by technology

Although the charging voltage of each single lithium power battery is low in the parallel charging method, due to its many charging branches, the current of each charging branch is relatively large, and the total charging current of each branch of the charger is relatively high. The volume is very large, so the cost is quite high, which makes the charging device of lithium power battery very expensive and difficult to realize

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