Six phase Synchronous Motor

These six phase motors are designed based on permanent magnetsynchronous brushless servo motors, using a dual three-phase winding asymmetricphase shift design of 30 ° (with a 30 degree intervalbetween the two sets of windings). All intermediate nodes of the six phasemotors (dual three-phase windings) are led out, with a total of 12 motor leadsand a built-in 2500 wire photoelectric encoder or rotary converter. It can bewidely used in ship propulsion systems, automotive power systems, power controlsystems, and other high-end power systems.

The phase band angle of the asymmetric six phase motor is consistentwith that of the symmetric twelve phase motor, which is 30 °. Therefore, its magnetic potential spatial distribution isconsistent with that of the symmetric twelve phase motor, that is, theasymmetric six phase motor eliminates the 5th and 7th harmonic magneticpotentials internally, thereby eliminating the 6th torque ripple. The minimumnumber of torque pulsations has been increased to 12, thus it has a greateradvantage in suppressing torque pulsations.

A six phase motor can achieve high power output at low voltage. Asthe number of phases in the motor increases, the permanent magnet flux or backelectromotive force of each phase winding will decrease proportionally,resulting in a decrease in the supply voltage, which can achieve high poweroutput at low voltage.

When one or more phase faults occur in the stator winding of a sixphase motor, it can be operated at reduced capacity without the need for aneutral line, and there is no need to stop and reassemble. In this case, byadopting an appropriate fault-tolerant control strategy, the remaining motorwindings can be recombined into a circular rotating magnetic potentialtrajectory, allowing the motor to continue stable operation. Therefore,multiphase motors are very suitable for high reliability requirements where midstop is strictly prohibited.

As the number of motor phases increases,the number of spatial harmonics increases, and the frequency of torque rippleincreases

High amplitude reduces the noise and vibration during motoroperation. The more phases a motor has, the higher the frequency of torqueripple generated by the fundamental current.

For a six phase motor, constant torque can be generated by injectinga suitable ratio of low order harmonic current and corresponding harmonicmagnetic field, thereby increasing the power density of the motor. The spatialvoltage vector of multiphase inverters increases exponentially, providingabundant control resources for the control of multiphase motors, such as PWMmodulation, direct torque control, and predictive current control. Multiphasemotors can achieve decoupling of fundamental torque components and harmonic componentsthrough vector space decoupling; By controlling the harmonic sub planecomponents, dead zone compensation and asymmetric compensation can be achieved;Overmodulation and parameter identification can also be achieved by injectingharmonic components.