Voltage limitation control considering battery module balancing for serial connection UPS module system

Voltage limitation control considering battery module balancing for series connection UPS module system is proposed. The UPS modules system is consists of single master module and multi slave modules. The voltage limitation control is performed to balance the battery modules of UPS system. Firstly, the master module checks the SOC of UPS modules to make order according to SOC. And, the master module calculates points to limit output voltage to control output power of the modules. Finally, the output voltage becomes sum of output voltage of UPS modules because of the series connection. As a result, the utilization of the battery can be increased in series connection UPS system. The validity of proposed voltage limitation control considering battery modules balancing is verified by simulation results.