Scalable multi-port converter for solar electric vehicles

A three-port isolated active bridge DC-DC power converter system, comprising:

• a plurality of three-port isolated active bridge DC-DC power converters, each comprising:
• a control unit;
• a primary side, comprising:
• a single first primary-side port;
• a single second primary-side port;
• two primary-side switching elements;
• a primary-side converter inductance;
• the two primary-side switching elements and the primary-side converter inductance being arranged to form a half-bridge arrangement for bidirectionally converting power between the first primary-side port and the second primary-side port;
• a primary-side transformer winding;
• wherein:
• the control unit is configured to control the two primary-side switching elements to convert power between the first primary-side port and the second primary-side port;
• a secondary side, comprising:
• a secondary-side port;
• two secondary-side switching elements;
• a secondary-side transformer winding, magnetically coupled to the primary-side transformer winding;
• the two primary-side switching elements, the primary-side transformer winding, the two secondary-side switching elements and the secondary-side transformer winding being arranged to form an isolated DC-DC converter between the primary side and the secondary side;
• a blocking switch;
• wherein:
• the control unit is configured to open the blocking switch to prevent power flow between the primary side and the secondary side and to close the blocking switch to allow power flow between the primary side and the secondary side;
• and
• the control unit is configured to control the two primary-side switching elements and the two secondary-side switching elements for converting power between the primary-side ports and the secondary-side port;
• a first system port;
• a second system port;
• wherein:
• the plurality of three-port isolated active bridge DC-DC power converters are coupled in parallel through their second primary-side ports to form the first system port;
• the plurality of three-port isolated active bridge DC-DC power converters are coupled in series through their secondary-side ports to form the second system port;
• one of the three-port isolated active bridge DC-DC power converters is designated as a master power converter, wherein the control unit of the master power converter is configured to control the output current of the master power converter based on an output current setpoint, wherein the output current of the master converter is the output current flowing to the secondary-side port of the master power converter;
• the remaining three-port isolated active bridge DC-DC power converters are designated as slave power converters, wherein the control unit of each of the slave power converters is configured to control the output voltage of its respective slave power converter to match the output voltage of the master power converter, wherein the output voltage of each slave power converter is the output voltage of the secondary-side port of the respective slave power converter and the output voltage of the master power converter is the output voltage of the secondary-side port of the master power converter, or wherein the control unit of each of the slave power converters is configured to control the output voltage of its respective slave power converter to be the inverse of the product of the number of three-port isolated active bridge DC-DC power converters of the three-port isolated active bridge DC-DC power converter system and the output voltage of the second system port.