Balancing stacked capacitor converters

An AC-DC power conversion system comprising:

• a first stacked half bridge converter coupled across an AC input of the AC-DC power conversion system, the first stacked half bridge converter further comprising:
• a first half bridge including two switching devices in a half bridge configuration and a first capacitor coupled thereacross;
• and
• a second half bridge further comprising two switching devices in a half bridge configuration and a second capacitor coupled thereacross;
• a transformer having a primary winding coupled to the first stacked half bridge converter by a blocking capacitor and a secondary winding;
• a second stacked half bridge converter coupled between the secondary winding of the transformer and an output of the AC-DC power conversion system, the second stacked half bridge converter further comprising:
• a first half bridge further comprising two switching devices in a half bridge configuration and a first capacitor coupled thereacross;
• and
• a second half bridge further comprising two switching devices in a half bridge configuration and a second capacitor coupled thereacross;
• and
• control circuitry that operates the switching devices of the first and second stacked half bridge converters so that the first stacked half bridge converter acts a flying capacitor to equalize charge between the first and second capacitors using the blocking capacitor as a flying capacitor to equalize charge between the first and second capacitors.

A DC-DC power conversion system comprising:

• a stacked half bridge converter coupled across a DC input of the DC-DC power conversion system, the stacked half bridge converter further comprising:
• a first half bridge including two switching devices in a half bridge configuration and a first capacitor coupled thereacross;
• and
• a second half bridge further comprising two switching devices in a half bridge configuration and a second capacitor coupled thereacross;
• a transformer having a primary winding coupled to the stacked half bridge converter by a blocking capacitor and a secondary winding;
• a full bridge converter coupled between the secondary winding of the transformer and an output of the DC-DC power conversion system, the full bridge converter comprising four switching devices in a full bridge configuration;
• and
• control circuitry that operates the switching devices of the stacked half bridge converter and the full bridge converter so that the stacked half bridge converter acts a switched capacitor converter to equalize charge between the first and second capacitors.