Three-Level T-Type DC-DC Converter with DC Link Voltage Balancing Algorithm for Battery Energy Storage Systems Applications

The article presents a control system for a three-level DC-DC converter with a DC link voltage balancing algorithm, as applied to battery energy storage systems (BESS). Recently, the use of BESS for low-voltage networks has been increasing everywhere. As a rule, the BESS consists of a battery, a DC-DC converter, a grid inverter and a grid filter. Advanced grid inverters are built to a three-level topology to increase efficiency and improve the quality of the consumed current. Thus, the DC-DC converter must also have a three-level topology. The main disadvantage of three-level topology is the disbalance of the DC link voltages. The authors propose a control method for aT-type DC-DC converter with a DC link voltage balancing algorithm. An electrical model of the BESS was developed for testing the algorithm. The simulation results showed that the proposed algorithm allows balancing the voltage in four quadrants of the device operating mode.