Research Of Space Vector Pulse Width Modulation Of The Dual Three-phase Permanent Magnet Synchronous Motor

Compared with the conventional three-phase Permanent Magnet SynchronousMotor (PMSM), multiphase motor can be widely used in industrial and military areasbecause of excellent advantages such as lower requirements for the power supplyvoltage, larger output power and higher reliability.Dual three-phase PMSM as one kind of multiphase motors has been widelyresearched at present. This kind of motor always has two sets of three-phase windingsand the phase between the windings is30electrical degrees. However, seriouscross-coupling magnetic saturation has been found between the two sets of windingsfor this kind of motor which exerts a bad effect on the motor control. When the phaseis shifted to180degrees, the cross-coupling magnetic saturation between thewindings could be reduced a lot due to the change of the winding distribution. Thispaper focuses on the study of the mathematical model and speed control system forthe dual three-phase PMSM with phase shifted by180degrees.In order to accurately reflect the running characteristics of the motor in themagnetic saturation condition, the nonlinear relationship between the inductances andcurrents obtained from the finite element method are firstly analyzed, and then amathematical model considering cross-coupling magnetic saturation has also beenestablished. Using Matlab/Simulink modeling and simulation, unsaturatedmathematical model and the saturated mathematical model are analyzed andcompared. The simulation results could prove that the mathematical modelconsidering cross-coupling magnetic saturation can accurately reflect the runningcharacteristic of the motor in the magnetic saturation condition. To control the motorspeed excellently, a double closed-loop vector control system has been designed usingcontrol method which makesid equals zero. And the speed and current PI controllerparameters of the system are also designed. Then vector control system is modeledand simulated with the Matlab/Simulink. It is also applied to the two motor models.The results of the simulation show that the speed control system has a strongadaptability with fast response, small fluctuation and good stability.