A three-phase multi-functional battery energy storage system

A three-phase multi-functional battery energy storage system (BESS) is designed and implemented in this paper. When the utility power is in normal condition, the proposed BESS can be arranged to shave the peak load or charge the battery bank. In either case, since the load is unbalanced, harmonic and reactive powers can be compensated through the proposed active power filtering control, the power factor is maintained near to unity and the line currents drawn from the utility are balanced and sinusoidal with very low distortion. As a utility power failure occurs, the proposed BESS can immediately supply uninterruptible power to the loads. In this case, an instantaneous control technique is developed to yield good three-phase voltage waveforms. The determination of reactive components, the dynamic modeling and the design of controllers for the proposed BESS are made. Some experimental results are provided to demonstrate the effectiveness of the proposed BESS