This paper proposes a design method for a secondary battery system using an active-neutral point clamped (A-NPC) inverter. The
proposed system consists of a secondary
battery, 3-level DC/DC converter, DC-link capacitor, and bi-directional A-NPC
inverter,
respectively. The conventional neutral
point clamped (NPC) inverter has limitation on switching the switching loss of
IGBT into a
particular element to increase the
switching frequency. This paper proposes a modulation method for implementing
the A-NPC
converter instead of the existing NPC
converter to address the loss of the unbalances. The simulation verifies the
validity of the analysis
results and the validity of the secondary
cell charging system by suggesting the analysis results of the IGBT according
to the
modulation method.