Output filter for medium voltage converters: Characterization of its performance under fault and for different types of connection and grounding conditions

In general, the switching frequency of medium voltage converters is limited to a few hundred Hz. Therefore, the harmonic distortion of its output voltage may be inadequate for supplying electric motors, requiring the use of filters. In this work, the performance of such filters is evaluated in fault conditions and also for different connection types and grounding of the filter and/or the transformer. Issues such as displacement of voltage levels, potentially dangerous to the integrity of the filter, converter and motor, along with the behavior of the common mode quantities in the system, are also evaluated. A comprehensive case study covering such aspects was conducted in Matlab/Simulink
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through the appropriate modeling of the whole system. The results and corresponding conclusions are shown in detail throughout the paper.