Research On Driving System Of Hybrid Excitation Doubly-salinet Permanent Motor Fed By T-type Three-level Converter

The Hybrid field-exciting Doubly-salient Permanent Magnet(HDSPM)machine is based on the Doubly-salient Permanent Magnet(DSPM)machine and the Doubly-salient Electro-magnet(DSEM)machine.Thus,more and more attention having been paid to this motor,it has many advantages such as simple structure,flexible control,high reliability,high efficiency,etc.The hard field adjustment of the DSPM machine and the low efficiency of the DSEM machine have been better solved by the HDSPM machine,it has great application values in many industrial fields and the military fields such as the aerospace,the ships.In this thesis,a HDSPM machine which fed by the T-type three-level converter and drived by multilevel current hysteresis controller is chosen as research object.The control strategy and the HDSPM machine drive system are deeply studied and demonstrated.The main contents include:1.The structure and working principle of the HDSPM machine are introduced.Based on FEM analysis,the mathematical model of the HDSPM machine in the natural stationary coordinate system is established.2.According to the torque equation of HDSPM machine,a torque observer which only needs to measure the three-phase current is constructed.Based on the detailed analysis of each torque component and torque ripple,a torque ripple minimization strategy is proposed.The reference current in the two-phase conducting period and commutation period is calculated considering the back EMF waveform,and three-phase conduction is applied in the commutation period.3.A current hysteresis modulation strategy based on the T-NPC three-level converter is proposed.Owing to the benefit of current hysteresis control,the system possesses the advantages of simple structure,quick response and smaller current ripple because of three-level technique.In addition,the scheme overcomes the problem associated with unbalanced neutral-point voltage.4.The characteristics of open-end winding HDSPM machine and the dual T-NPC three-level converter under open winding topology are studied.The torque ripple suppression strategy and the multilevel current hysteresis controller are extended to the dual port converter,the neutral-point voltage regulation strategy is further improved.Furthermore,the zero sequence current of the open winding system based on the current hysteresis controller is introduced5.A driving system based on DSP and FPGA is set up to demonstrate the theoretical and simulated results,and the characteristics of each hardware circuit are introduced.The C language program based on DSP chip and the Verilog language based on FPGA chip are completed,and all the control algorithms of different control strategy are realized in this paper.Combined with the experimental equipment in the laboratory,the manufacture of the experimental platform is completed.And the HDSPM prototyped machine experiments are given to verify the correctness of theoretical analysis and proposed schemes.