A new algorithm to determine the magnitudes of dc voltage sources in asymmetric cascaded multilevel converters capable of using charge balance control methods

In this paper, a new algorithm is proposed to determine the magnitudes of dc voltage sources used in asymmetric cascaded multilevel converters. Using this algorithm, it is possible to generate the maximum number of output voltage levels and maximum output voltage amplitude using the minimum number of dc voltage sources. The magnitudes of dc voltage sources are determined in a way considering which it is possible to use charge balance control methods to all dc sources except the minimum amplitude dc voltage source (first bridge). Therefore, the lifetime of dc voltage sources used in different bridges of cascaded asymmetric multilevel converter except the first bridge are the same, considering which the system´s low maintenance cost can be noted as a result. The simulation results in PSCAD/EMTDC confirm the abilities of the proposed method.