Abstract: According to an embodiment, there is provided an apparatus which can hold down an energy loss and can avoid an increase in size. The apparatus includes a cell including a floating capacitor connected in parallel to an upper-side switching element and a lower-side switching element; an upper arm include including first switch circuits, each including a first switching element, a first diode and a first capacitor, are connected in series; a lower arm including second switch circuits, each including a second switching element, a second diode and a second capacitor, are connected in series; and a circuit which connects a low-side terminal of the cell and a low-side terminal of the first capacitor and connects a high-side terminal of the cell and a high-side terminal of the second capacitor.

Abstract: According to an embodiment, there is provided an apparatus which can hold down an energy loss and can avoid an increase in size. The apparatus includes a cell including a floating capacitor connected in parallel to an upper-side switching element and a lower-side switching element; an upper arm include including first switch circuits, each including a first switching element, a first diode and a first capacitor, are connected in series; a lower arm including second switch circuits, each including a second switching element, a second diode and a second capacitor, are connected in series; and a circuit which connects a low-side terminal of the cell and a low-side terminal of the first capacitor and connects a high-side terminal of the cell and a high-side terminal of the second capacitor.

Abstract: In a voltage adjusting apparatus connected in series to a system, an output of an AC/DC converter thereof is reduced. The apparatus includes a second serial transformer having a primary side connected in series to a secondary side of a first serial transformer having a primary side connected in series between a power supply and a load and to a secondary side of a parallel transformer having a primary side connected in parallel between the power supply and the load; and a first AC/DC converter having an AC side connected to a secondary side of the second serial transformer. The first AC/DC converter has a switching element connected between an AC terminal and a DC terminal, an antiparallel diode, and a capacitor.

Abstract: In a voltage adjusting apparatus connected in series to a system, an output of an AC/DC converter thereof is reduced. Provided are: a second serial transformer 21 having a primary side connected in series to a secondary side of a first serial transformer 13 having a primary side connected in series to the system and to a secondary side of a parallel transformer 14 having a primary side connected in parallel to the system; and a first AC/DC converter 22 having an AC side connected to a secondary side of the second serial transformer 21. The first AC/DC converter 22 has a switching element 22c connected between an AC terminal 22a and a DC terminal 22b, an antiparallel diode 22d, and a capacitor 22e.