A power conversion device to convert power between an AC circuit and a DC circuit, the power conversion device comprising: a plurality of positive-side arm circuits (6au, 6av, 6aw) connected between a plurality of AC connections (Nu, Nv, Nw) connected to the AC circuit and a positive-side DC terminal (Np) connected to the DC circuit; a plurality of negative-side arm circuits (6bu, 6bv 6bw) connected between the plurality of AC connections (Nu, Nv, Nw) and a negative-side DC terminal (Nn) connected to the DC circuit; and a bypass circuit, each of the positive-side arm circuits (6au, 6av, 6aw) and each of the negative-side arm circuits (6bu, 6bv 6bw) each including a plurality of converter cells (21F, 21H, 21HYB) connected in series, each of the converter cells (21F, 21H, 21HYB) including: an energy storage; and a bridge circuit (28H, 28F, 28HYB) to switch connection between the energy storage and outside, the bypass circuit including: a full-wave rectification circuit connected between the plurality of AC connections (Nu, Nv, Nw), a positive-side intermediate node (Npd), and a negative-side intermediate node (Nnd) to convert AC voltages generated at the plurality of AC connections (Nu, Nv, Nw) into a DC voltage across the positive-side intermediate node (Npd) and the negative-side intermediate node (Nnd) and output the DC voltage; a positive-side connection arm connected between the positive-side intermediate node (Npd) and the positive-side DC terminal (Np), the positive-side connection arm blocking a current in a direction from the positive-side DC terminal (Np) toward the positive-side intermediate node (Npd); and a negative-side connection arm connected between the negative-side intermediate node (Nnd) and the negative-side DC terminal (Nn), the negative-side connection arm blocking a current in a direction from the negative-side intermediate node (Nnd) toward the negative-side DC terminal (Nn). a plurality of positive-side arm circuits (6au, 6av, 6aw) connected between a plurality of AC connections (Nu, Nv, Nw) connected to the AC circuit and a positive-side DC terminal (Np) connected to the DC circuit; a plurality of negative-side arm circuits (6bu, 6bv 6bw) connected between the plurality of AC connections (Nu, Nv, Nw) and a negative-side DC terminal (Nn) connected to the DC circuit; and a bypass circuit, each of the positive-side arm circuits (6au, 6av, 6aw) and each of the negative-side arm circuits (6bu, 6bv 6bw) each including a plurality of converter cells (21F, 21H, 21HYB) connected in series, each of the converter cells (21F, 21H, 21HYB) including: an energy storage; and a bridge circuit (28H, 28F, 28HYB) to switch connection between the energy storage and outside, an energy storage; and a bridge circuit (28H, 28F, 28HYB) to switch connection between the energy storage and outside, the bypass circuit including: a full-wave rectification circuit connected between the plurality of AC connections (Nu, Nv, Nw), a positive-side intermediate node (Npd), and a negative-side intermediate node (Nnd) to convert AC voltages generated at the plurality of AC connections (Nu, Nv, Nw) into a DC voltage across the positive-side intermediate node (Npd) and the negative-side intermediate node (Nnd) and output the DC voltage; a positive-side connection arm connected between the positive-side intermediate node (Npd) and the positive-side DC terminal (Np), the positive-side connection arm blocking a current in a direction from the positive-side DC terminal (Np) toward the positive-side intermediate node (Npd); and a negative-side connection arm connected between the negative-side intermediate node (Nnd) and the negative-side DC terminal (Nn), the negative-side connection arm blocking a current in a direction from the negative-side intermediate node (Nnd) toward the negative-side DC terminal (Nn). a full-wave rectification circuit connected between the plurality of AC connections (Nu, Nv, Nw), a positive-side intermediate node (Npd), and a negative-side intermediate node (Nnd) to convert AC voltages generated at the plurality of AC connections (Nu, Nv, Nw) into a DC voltage across the positive-side intermediate node (Npd) and the negative-side intermediate node (Nnd) and output the DC voltage; a positive-side connection arm connected between the positive-side intermediate node (Npd) and the positive-side DC terminal (Np), the positive-side connection arm blocking a current in a direction from the positive-side DC terminal (Np) toward the positive-side intermediate node (Npd); and a negative-side connection arm connected between the negative-side intermediate node (Nnd) and the negative-side DC terminal (Nn), the negative-side connection arm blocking a current in a direction from the negative-side intermediate node (Nnd) toward the negative-side DC terminal (Nn).