Three-phase AC-to-AC series resonant power converter with reduced number of switches

An improved three phase AC to AC series resonant converter for transferring electrical power between a first, second and third phase input and a first, second and third phase output, comprising:

• a series resonant circuit including a capacitor and an inductor connected in series;
• first, second and third bidirectional input switch means connecting the first, second and third phase inputs to said series resonant circuit, respectively;
• first, second and third bidirectional output switch means connecting the first, second and third phase outputs to said series resonant circuit, respectively;
• first, second and third input capacitor means connected to the first, second and third phase inputs, respectively;
• first, second and third output capacitor means connected to the first, second and third phase outputs, respectively;
• and
• means connecting said first, second and third input capacitor means in series with said first, second and third output capacitor means, respectively, for enabling only six bidirectional switches to interconnect the first, second and third phase inputs to the first, second and third phase outputs.

An improved three phase AC to AC series resonant converter for transferring electrical power between a first, second and third phase input and a first, second and third phase output, comprising:

• a series resonant circuit including a capacitor and an inductor with said capacitor being connected in series with said inductor;
• first, second and third bidirectional input switch means
• first, second and third bidirectional output switch means;
• said first bidirectional input switch means and said first bidirectional output switch means interconnecting the first phase input with the first phase output with said series resonant circuit being interposed between the said first bidirectional input switch means and said first bidirectional output switch means;
• said second bidirectional input switch means and said second bidirectional output switch means interconnecting the second phase input with the second phase output with said series resonant circuit being interposed between the said second bidirectional input switch means and said second bidirectional output switch means;
• said third bidirectional input switch means and said third bidirectional output switch means interconnecting the third phase input with the third phase output with said series resonant circuit being interposed between the said third bidirectional input switch means and said third bidirectional output switch means;
• first, second and third input capacitor means;
• first, second and third output capacitor means;
• said first, second and third input capacitor means being connected in series with said first, second and third output capacitor means between the first, second and third inputs and the first, second and third outputs, respectively;
• and
• said first, second and third input and output capacitor means being connected in parallel to said series resonant circuit between the first, second and third inputs and outputs for enabling for enabling only six bidirectional switches to interconnect the first, second and third phase inputs to the first, second and third phase outputs.