Grid-connected Battery Test System with AC regenerating capability

In this paper, battery test system with AC regeneration capability is proposed. The proposed 5kW battery test system consists of 32 channels of battery module, two three-phase bi-directional isolated interleaved dc-dc converters and three-phase inverter. In discharge mode, energy from batteries is delivered to grid and energy is delivered to battery from grid in charge mode. Grid currents are sinusoidally controlled with low THD and unity power factor, and average current sharing control is implemented for balanced parallel operation in three-phase dc-dc converters. By using this method, unbalance factor is maintained within 1%. Two 5kW battery test system are built and the proposed several control methods are verified through experiments.