Due to new technological possibilities decentral structures will characterize the future electrical energy grid. To ensure the energy transport and to increase the efficiency Medium-Frequency High-Voltage (MF-HV) transformers are used. With these inductive couplers the electrical isolation between loads, sources and the AC-distribution system is possible. In this process a superposition of the MF-HV generated by power electronic circuits and the power frequency voltage occurs. Figure 1 shows the calculated voltage waveforms of these Multi-Cell Solid-State Transformers for two different power electronic topologies (3LL and 2LL), which are described in [1]. The voltage consists of a 50 Hz component and medium frequency harmonics.