Study On Intelligent Charger For Power Battery And Charging Strategy Of Ni-MH Battery

Electric Vehicle (EV) has become a kind of fast-developing vehicle in recent years as the problems of energy and environment are becoming increasingly serious. Charging facility is one of the most important parts of EV. It is significant to develop an efficient, low-consumption and rapid strategy for the application and development of EV.In this paper, an intelligent charger is introduced, which adopts half-bridge DC/DC as main charging circuit, MCS-51 single chip as controller of the panel and digital signal processor (DSP) as controller of charging procedure. During the charging process, the battery parameters, charging state and faults information could be displayed on the LCD. Both manual and automatic modes could be applied to three kinds of power batteries.After summarizing the charging strategy of mainly used power batteries, the rapid charging scheme for Nickel-Metal Hydride battery (Ni-MH) is studied. A novel charging method is proposed, which uses graded charging current, and takesΔv /Δt, voltage curve inflexion, small current charging-discharging as sign of switching current grade, terminating condition and intermission mode, respectively.The panel design based on MCS-51 is described in detail, including function design, operating instruction, hardware and software design. The charging controller design based on DSP includes sampling, communicating, faults detecting and control programs. A few software and hardware anti-jamming measures are used to enhance the reliability of the system.As for the rapid charging method of Ni-MH battery, a circuit topology with DC/DC converter is proposed, which uses large current discharging pulse and small current charging-discharging in order to depolarize. The value selection of inductance and capacitor is analyzed.The intelligence of this charger can be described as follows: different batteries application, battery information sampling, battery manage system communication for details, recent parameters saving for batch charging, experienced data acceptance and automatic failure detection. It could realize the function of efficient charging, mending and protecting for battery.