| Abstract |
This paper presents three-level converters used in distributed power systems (DPS) applications. Three categories of converters are addressed in the paper: (1) two-stage approach, (2) quasi-single-stage solution and (3) single-stage converter. The two-stage approach is deemed the most advantageous in achieving high efficiency, while the simplicity of the single-stage topologies can reduce the cost of the DPS front-end converter. The quasi-integrated front-end converter discussed in the paper represents a tradeoff between performance and cost, since it needs the same number of switches as compared to the single-stage approach but eliminates the fluctuation of the intermediate bus voltage. The paper compares all solutions in terms of overall efficiency, harmonic distortion, intermediate bus voltage stress and size of the input filter under interleaved operation. The power level application target addressed in the paper is 3kW for single converter or 6kW when two converters are interleaved to provide input current ripple cancellation. |
