MOTOR CONTROL SYSTEM AND METHOD

A highly efficient and reliable motor control system and motor control method are provided. The motor control system includes a motor having a plurality of sets of armature windings, a plurality of inverters which drive the plurality of sets of armature windings, and a plurality of control devices which control the inverters individually. In the motor control system: while a motor torque command is in a smallest-magnitude range, a first inverter is operated to energize a first set of armature windings; when the motor torque command increases into a next larger-magnitude range, the first and a second inverter are operated to energize the first and a second set of armature windings; when the motor torque command increases into a still next larger-magnitude range, the first, the second, and a third inverter are operated to energize the first, the second, and a third set of armature windings; and when the motor torque command increases into a largest-magnitude range, all inverters are operated to energize all sets of armature windings. Thus, the number of inverters driven and/or the number of sets of armature windings energized are sequentially changed according to the torque command.