Abstract: Disclosed is a pole-change type motor that provides a variable-speed (two-pole or four-pole type) operation system capable of reducing the load of the motor of the normal operation system and improving the cooling efficiency. In case of a quick operation, the motor switches over to the two-pole type according to the control of a relay section. At this time, the load of the motor is reduced by offsetting an abnormal magnetic field distribution formed due to the same polarity of adjacent main windings using compensation windings of an opposite polarity. If the quick operation is needed, the motor switches over to the two-pole type, and operates at a high speed to achieve the quick cooling. Then, if a standard operation is possible with the lapse of the predetermined time, the motor switches over to the four-pole type, and operates at a low speed to achieve an effective cooling.

Abstract: Disclosed is a pole-change type motor that provides a variable-speed (two-pole or four-pole type) operation system capable of reducing the load of the motor of the normal operation system and improving the cooling efficiency. In case of a quick operation, the motor switches over to the two-pole type according to the control of a relay section. At this time, the load of the motor is reduced by offsetting an abnormal magnetic field distribution formed due to the same polarity of adjacent main windings using compensation windings of an opposite polarity. If the quick operation is needed, the motor switches over to the two-pole type, and operates at a high speed to achieve the quick cooling. Then, if a standard operation is possible with the lapse of the predetermined time, the motor switches over to the four-pole type, and operates at a low speed to achieve an effective cooling.