Based on a brushless motor

 In order to facilitate the control system modeling and single phase motor price analysis of needs, we main to control coil current by convention, rather than to control the stator magnetic field. Because we can easily detect the motor current, the magnetic flux (the actual) is difficult to get. In the brushless motor, coil current directly through the three groups produced the stator magnetic field. Because of the three group of coil is man-made according to the installation of 120 - degree Angle difference to each other, so the magnetic field generated by the three groups of coil there is also a 120 - degree Angle difference to each other. And www.dongfeng-motor.com the three magnetic field overlap with the stator magnetic field is produced. 

To flow through the stator coil magnetic field modeling, we introduced the concept of "space current vector". Fixed coil current space vector has a fixed magnetic field direction, it 3 phase induction motor is entirely by magnetic flux through a coil coil size and the current interaction. In this way, we can use the space current vector ac motor to represent the stator magnetic field, the space current vector is of three groups of coil current generated by the vector space superposition. Explain the space current vector is an intuitive way, we can assume that the stator consists of a set of coils, only this group of coil and the current generated by the magnetic field and the superposition of three groups of coil to produce magnetic field in front of is the same.