Design and Simulation of a Dual Conversion Transformerless Online and Line-Interactive UPS

Abstract

In this paper, a dual-conversion online static UPS and Line-Interactive UPS system was modeled and simulated using PSIM software. The components of the proposed design were specified based on pre-defined constrains, and the dynamic behavior of the system was modeled through state-space equations. With the system components characterized, a suitable controller was developed for closed-loop control of the buck and boost circuits. A battery charge management controller was also developed to ensure the robustness of the design. Overall system performance was analyzed under varying load and line conditions. Conversion bypass switching was simulated and the overall system performance was analyzed while observing the state of charge – SOC behavior of the battery.