DC-DC converter with modular stages

An apparatus for electric power conversion, said apparatus comprising:

• a converter having a path for a power flow between a first terminal and a second terminal;
• said converter comprising
• a regulating circuit on the path for the power flow, said regulating circuit having one or more ports, the regulating circuit including
• one or more inductors, and
• one or more switching elements connected to said one or more inductors, said one or more switching elements being controllable to switch between switching configurations,
• wherein, said regulating circuit is controllable to maintain a current through each of the one or more ports according to currents in the one or more inductors;
• and
• said converter further comprising
• a switching network on the path for the power flow, the switching network having a plurality of ports at least some of said ports being coupled to the one or more ports of the regulating circuit, said switching network including
• a plurality of charge storage elements, and
• switching-network switching elements connected to said charge storage elements, said switching-network switching elements being controllable to switch between switch configurations,
• wherein, in one switch configuration in operation, said switching-network switching elements form a first arrangement of the plurality of charge storage elements in which
• a first charge storage element of the plurality of charge storage elements is charged at a rate determined by a current through at least a first port of the one or more ports of the regulating circuit and
• a second charge storage element of the plurality of charge storage elements is discharged at a rate determined by a current through at least a second port of the one or more ports of the regulating circuit,
• wherein in another switch configuration of the switching-network switching elements in operation, said switching-network switching elements form a second arrangement of charge storage elements in which the first charge storage element is discharged at a rate determined by a current through at least a third port of the one or more ports of the regulating circuit and the second charge storage element is charged at a rate determined by a current through at least a fourth port of the one or more ports of the regulating circuit.