BALANCING MULTILEVEL DC-DC CONVERTER APPARATUS

An apparatus includes a string of capacitors including at least two capacitors coupled in series and a switching circuit including a first port having first and second terminals connected to a first node and a second end node, respectively, of the string of capacitors, and a second port configured to be coupled to an energy storage device. The switching circuit is configured to selectively connect first and second terminals of the second port to a first end node, a second end node, and at least one interconnection node of the string of capacitors. The apparatus also includes at least one inductor configured to be coupled in series with the second port of the switching circuit and the energy storage device and a charging switch configured to directly connect the first terminal of the second port to the second terminal of the second port. The apparatus further includes a control circuit configured to close the charging switch to charge the inductor from the energy storage device in first intervals and to selectively close at least two switches of the switching circuit in second intervals to selectively charge the capacitors of the string of capacitors from the charged at least one inductor.