Dual active bridge optimization with triple phase shift and variable inductor

A converter comprising:

• a high-voltage (HV) H-bridge connected to a HV voltage and including first and second HV legs;
• a low-voltage (LV) H-bridge connected to a LV voltage and including first and second LV legs;
• a transformer connecting the HV and the LV H-bridges;
• and
• a variable inductor connected between the HV H-bridge and the transformer;
• and
• a controller configured or programmed to:
• operate in low, medium, and high power modes;
• control switching of switches in the HV and the LV H-bridges using triple-phase-shift control;
• control an inductance of the variable inductor such that the converter is operated in the medium power mode near a boundary between the low and the medium power modes using a first proportional-integral (PI) controller based on a comparison of:
• a parameter x based on a comparison of a reference voltage and a measured voltage corresponding to either the HV voltage or the LV voltage;
• and
• a first boundary value corresponding to the boundary between the low and the medium power modes.

A method of controlling a converter, the converter including:

• a high-voltage (HV) H-bridge connected to a HV voltage and including first and second HV legs;
• a low-voltage (LV) H-bridge connected to a LV voltage and including first and second LV legs;
• a transformer connecting the HV and the LV H-bridges;
• a variable inductor connected between the HV H-bridge and the transformer;
• and
• switches in the first and second HV legs and in the first and second LV legs, the method comprising:
• operating the converter in low, medium, and high power modes;
• switching the switches using triple-phase-shift control;
• and
• controlling an inductance of the variable inductor to control current in the switches in the second HV leg at turn off and at turn on such that the converter is operated in the medium power mode near a boundary between the low and the medium power modes using a proportional-integral (PI) control based on comparing:
• a parameter x based on comparing a reference voltage and a measured voltage corresponding to either the HV voltage or the LV voltage;
• and
• a first boundary value corresponding to the boundary between the low and the medium power modes.