Bi-directional multi-port applications

A bi-directional power converter, comprising:

• at least two phase legs each connected to a respective phase line of a first port;
• each said phase leg comprising two fully bidirectional switching devices, so that the line connected to that phase leg can either source or sink current to either terminal of a link inductor which is paralleled by a capacitor;
• at least two other phase legs each connected to a respective line of a second port;
• each said phase leg comprising two fully bidirectional switching devices, so that the line connected to that phase leg can either source or sink current to either terminal of said link inductor;
• wherein said lines of said second port provide three phase lines and a neutral line;
• at least two other phase legs each connected to a respective phase line of a third port;
• each said phase leg comprising two fully bidirectional switching devices, so that the line connected to that phase leg can either source or sink current to either terminal of said link inductor;
• and,
• control circuitry which is connected to drive said switches so that said link inductor is coupled to each said phase line of said first and second ports at least twice, with opposite polarities, during each full cycle of AC oscillation of said link inverter;
• and
• wherein said control circuitry is also connected to detect drift of the neutral line of said second port, and configured to apply drive to said neutral line.