Power converter

A power converter comprising:

• a first DC terminal and a second DC terminal;
• a power converter circuit including a plurality of first switching elements and a plurality of second switching elements, the power converter circuit being implemented as a parallel connection of a plurality of switching circuits in each of which one of the plurality of first switching elements and a corresponding one of the plurality of second switching elements are connected one to one in series, the plurality of first switching elements being connected to the first DC terminal, the plurality of second switching elements being connected to the second DC terminal;
• a plurality of AC terminals provided one to one for the plurality of switching circuits, each of the plurality of AC terminals being connected to a connection node between the first switching element and the second switching element of a corresponding one of the plurality of switching circuits;
• a plurality of switches provided one to one for the plurality of switching circuits, each of the plurality of switches having a first terminal thereof connected to the connection node between the first switching element and the second switching element of a corresponding one of the plurality of switching circuits, the plurality of switches having their respective second terminals connected in common to a common connection node;
• a plurality of resonant capacitors provided one to one for the plurality of switches, each of the plurality of resonant capacitors being connected between the first terminal of a corresponding one of the plurality of switches and the second DC terminal;
• a resonant inductor having a first terminal and a second terminal, the first terminal of the resonant inductor being connected to the common connection node;
• a regenerative capacitor having a third terminal and a fourth terminal, the third terminal of the regenerative capacitor being connected to either the first DC terminal or the second DC terminal;
• and
• a controller configured to apply a PWM signal, having a potential alternating between a high level and a low level, to each of the plurality of first switching elements and the plurality of second switching elements,
• the controller being configured to perform a first control operation, the first control operation including:
• setting, with respect to each of the plurality of switching circuits, a dead time between a high-level period of the PWM signal for the first switching element and a high-level period of the PWM signal for the second switching element;
• allowing a high-level period of a control signal for each of the plurality of switches, corresponding to one of the plurality of switching circuits, to overlap with the dead time;
• and setting a beginning of the high-level period at a point in time earlier by an additional time than a beginning of the dead time, and
• the controller being configured to selectively perform, according to a potential detected at the fourth terminal of the regenerative capacitor and polarities of a plurality of output currents supplied from the plurality of AC terminals, either a second control operation or a third control operation, the second control operation including allowing respective high-level periods of control signals for two switches belonging to the plurality of switches to overlap with each other, the third control operation including prohibiting the high-level periods of the control signals for the plurality of switches from overlapping with each other.