Figure 2: Power electronic topologies with DC transmission [5]: (G-A) grid connection via DC-AC converter and transformer; (G-B) grid connection via DC-DC converter with medium-frequency transformer and DC-AC converter; (K-A) medium-voltage generators and AC-DC converters on kite; (K-B) low-voltage generators with low-voltage AC-DC converter and DC-DC converter with medium-frequency transformer; (K-C) the same as (K-B) but the DC-DC converter is connected to two low-voltage DC-AC converters and generators [5].