Integrated power conversion for DC power system by flying capacitor multi-level converter

Abstract

In a modern electrical power system, most of equipments have dc terminals as an interface or inside of them, but the electric power is distributed by ac. Therefore, they have to employ a power converter suitable for their circumstances to trade the electric power. However, as the converters cannot avoid conversion losses inherently, it is important to reduce the number of power conversion from an energy source to a load. On the other hand, there is a well-known topology of flying capacitor multilevel converter which has several terminals of different dc voltage and an ac voltage terminal. This paper proposes to utilize the topology as an integrated power conversion module. Their various dc and ac terminals can provide a wide variety of interfaces with the conventional ac grid, electrical equipments requiring different dc voltages, batteries, solar cells, etc. A typical application is introduced and evaluated by simulation study.