Compenstion of phase voltage error in unbalanced 3-phase at integrated ESS and UPS system

In this paper, integrated Energy Storage System(ESS) and Uninterruptible Power Supply(UPS) is suggested. Integrated ESS and UPS system not only improves the efficiency but also prevents the grid voltage error situation. Using this system, change of characteristic at the load makes unbalanced 3-phase voltage. The comparison shows considerable discrepancy between sensed phase voltage and actual phase voltage, when unbalance situation occurs. This discrepancy makes difficult to detect accurate phase voltage error, so it is hard to satisfy the standard for switching ESS to UPS system. In this paper, integrated ESS and UPS system is suggested. And also analyzed unbalanced 3-phase voltage, and compensated the error voltage to actual voltage magnitude.