Motor drive device

A motor drive device for an open winding type motor in which a stator winding includes three-phase windings, the motor drive device comprising:

• a plurality of single-phase inverters provided for each of the windings to individually apply a voltage to a corresponding winding;
• and
• a controller that controls each of the single-phase inverters provided for each of the windings,
• wherein the controller adjusts a 0-axis current to a predetermined value by alternately and repeatedly generating a first period in which a sum of voltages applied to the respective windings is set to a value other than zero to offset the 0-axis current and a second period in which the sum of the voltages applied to the respective windings is set to zero, the 0-axis current being an amount directly proportional to a total sum value of phase currents,
• wherein an offset amount in the first period is set such that an amplitude change of the 0-axis current from a start of the first period to an end of the subsequent second period is proportionally distributed above and below the predetermined value.