Motor drive device
View Patent ↗Provided is a motor drive device capable of adjusting a 0-axis current to a desired value. A motor drive device (inverter device 100 ) for an open winding type motor 200 in which a stator winding wire includes three-phase independent winding wires 210, 220 , and 230 includes a plurality of single-phase inverters 160, 170 , and 180 provided for each of the winding wires 210 to 230 to individually apply a voltage to a corresponding winding wire, and a controller 150 that controls each of the single-phase inverters 160 to 180 . The controller 150 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 independent winding wires 210 to 230 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 winding wires 210 to 230 is set to zero.
1. A motor drive device for an open winding type motor in which a stator winding wire includes three-phase independent winding wires, the motor drive device comprising:
a plurality of single-phase inverters provided for each of the winding wires to individually apply a voltage to a corresponding winding wire; and
a controller that controls each of the single-phase inverters provided for each of the winding wires,
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 winding wires 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 winding wires is set to zero.
2. The motor drive device according to claim 1 , wherein an offset amount in the first period is set such that an amplitude of the 0-axis current is smaller than an amplitude of a 0-axis current standing wave corresponding to a case in which the sum is set to zero.
3. The motor drive device according to claim 2 , wherein the offset amount in the first period is set to a value obtained by assigning a minus symbol to an amplitude value of the 0-axis current standing wave.
4. The motor drive device according to claim 1 , 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.
5. The motor drive device according to claim 4 , wherein the controller controls a d-axis current and a q-axis current in the second period.
6. The motor drive device according to claim 4 , wherein the controller generates a control period in which the first period and the second period are repeated in a predetermined period.
7. The motor drive device according to claim 1 , wherein when a voltage of a direct current (DC) power source supplied to each of the single-phase inverters is set to Ed,
the controller performs a control operation such that all voltages applied to U-phase, V-phase, and W-phase winding wires in the first period correspond to +Ed or −Ed.