A DVR built with a 5-level cascade asymmetric multilevel converter

The power quality (PQ) in distribution systems is principally affected by the pollution introduced by the customers. It is necessary to protect the sensitive loads from disturbances such as sags, swells, source voltage imbalances, etc. The actual solution for this case is to employ a dynamic voltage restorer (DVR) device. The use of multilevel inverters in medium voltage applications is a good solution. In particular, the cascaded asymmetric multilevel converter (CAMC) appears as a very attractive alternative among the 5-level converters for this application. The design of the CAMC as a DVR in a medium voltage distribution power system is presented in this paper. The model and the control strategy are discussed in d-q coordinates synchronous with the source voltage. The performance of the proposed compensator is tested with SPICE simulations.