A power supply system includes first and second DC power supplies and a power converter. The power converter includes first and third semiconductor elements electrically connected between respective nodes of a first node and a second node and a power line, second and fourth semiconductor elements electrically connected between respective nodes of the first node and the second node and a second power line, a fifth semiconductor element electrically connected between the first and second nodes, and first and second reactors. The first reactor is electrically connected in series with the first DC power supply, between the first node and the second power line. The second reactor is electrically connected in series with the second DC power supply, between the second power line and the second node. A control device controls on and off of the switching element included in the semiconductor element.