Dc/dc converter

A DC/DC converter comprising:

• a terminal group including a first terminal and a second terminal on a low-voltage side, and a third terminal and a fourth terminal on a high-voltage side;
• a first smoothing capacitor connected between the first terminal and the second terminal;
• a second smoothing capacitor connected between the third terminal and the fourth terminal;
• a switching element series circuit which includes a first switching element, a second switching element, a third switching element, and a fourth switching element connected in series in this order, and in which a connection point of the second and third switching elements is connected to the first terminal via a reactor, a terminal of the fourth switching element on a side opposite to a connection point of the third switching element and the fourth switching element is connected to the third terminal, and a terminal of the first switching element on a side opposite to a connection point of the first switching element and the second switching element is connected to the second terminal and the fourth terminal;
• a charge/discharge capacitor connected between the connection point of the first and second switching elements and the connection point of the third and fourth switching elements;
• and
• a control device for generating gate signals for driving the first, second, third, and fourth switching elements such that the gate signals for the first switching element and the fourth switching element have a complementary relationship, and the gate signals for the second switching element and the third switching element have a complementary relationship,
• the DC/DC converter performing conversion of DC voltage between:
• the first terminal and the second terminal on the low-voltage side;
• and the third terminal and the fourth terminal on the high-voltage side, wherein
• the control device includes:
• a duty command calculation unit for calculating duty command values for the first, second, third, and fourth switching elements on the basis of difference voltage between a high-voltage-side voltage command value which is a voltage command value for the high-voltage side, and a high-voltage-side voltage detection value which is a voltage detection value on the high-voltage side;
• and a phase shift duty command calculation unit for calculating a phase shift duty command value corresponding to a phase difference between the gate signals for the first and fourth switching elements and the gate signals for the second and third switching elements, on the basis of difference voltage between a voltage target value for the charge/discharge capacitor and a voltage detection value of the charge/discharge capacitor, and
• the control device generates the gate signals for driving the first, second, third, and fourth switching elements, on the basis of the duty command values and the phase shift duty command value.