THE DC MICRO-GRID CHARGING AND DISCHARGING SYSTEM FOR SERIAL CONNECTED SECONDARY BATTERIES

摘要

The present invention relates to a DC micro-grid charging and discharging system. According to the present invention, secondary batteries are connected in series so as to substantially increase charging and discharging voltages during a charging or discharging process, when compared to one battery. The required voltage of the DC micro-grid is twice, more or less, as high as the maximum voltage of a battery array. Therefore, efficiency of power conversion of a DC-DC converter for controlling charging and discharging power is increased. A linear constant current source is added to the system; thus, a charging or discharging process can be stably performed even when the battery array is changed. An electricity storing device, used for both charging and discharging process, is composed of combination of a common electrolyte condenser, a super condenser, or a secondary battery array; thus, power conversion efficiency of the charging and discharging system is increased. The present invention relates to: an algorithm that simplifies the system, and the DC micro-grid charging and discharging system to which the algorithm is applied.