Power conversion device

A power conversion device comprising:

• a power converter including an arm in which a plurality of converter cells are connected in series, each of the plurality of converter cells including at least two switching elements, a power storage element, and a pair of output terminals;
• and
• a control device to control the power converter,
• the converter cell including a switch to have the converter cell bypassed, wherein
• when the control device senses failure of a converter cell, the control device has a failed converter cell within the arm bypassed and controls a normal converter cell within the arm to suppress a ratio of a harmonic component in an arm current that increases due to the failure,
• the control device controls the normal converter cell within the arm based on a harmonic suppression control output value for suppressing the harmonic component in the arm current that increases due to the failure.