Development of uninterruptible secondary battery system

This paper presents the system configuration and control schemes of a USBS (uninterruptible secondary battery system), which acts as a battery energy storage system when no fault occurs in a commercial power network and functions as a UPS in case of network faults. If a fault such as a voltage interruption occurs on the network, the USBS disconnects critical loads from it instantly, and supplies power to them as a UPS. It takes less than 2 ms to restart supply power to the loads in case of an emergency, so no damage occurs. Simulations and experimental tests are carried out to confirm the feasibility of the proposed system.