Redundant, High Density, High Efficiency Double Conversion Uninterruptible Power System

This paper presents a novel design for double conversion UPS systems that results in higher power density, higher efficiency and more flexible parallelism for higher reliability. This design comprises a three-level circuit topology, a customized power semiconductor module and a cross current sensorless parallel control. The innovative circuit topology results in an UPS with higher efficiency and dramatic size/weight reduction and confirms the advantages of three-level circuits in low-voltage applications. Higher reliability uninterruptible power system using parallel redundant UPS modules employs a novel cross current sensorless control without compromise the performance in comparison with single-module systems. Test results using a single and a multiple module system confirm the improvement in efficiency and the high performance of this UPS.