Research On Direct Torque Control Method Of Six-phase Induction Motor Based On SVPWM

In recent years,China has made many achievements in all walks of life.The research on multi-phase motors is also in-depth.Compared with three-phase motors,multi-phase motors have many advantages and have received widespread attention.The main research object of this paper is a six-phase induction motor.The direct torque control method is used to control the motor,and the observation part of the stator flux linkage is improved,and a sliding mode observation model of the stator flux linkage is designed.For the six-phase SVPWM algorithm,the synthesis method of the intermediate vector is optimized,and the simulation analysis and experimental analysis are carried out in combination with the direct torque control method.Firstly,combined with the theoretical basis of the motor,the mathematical model of the six-phase induction motor is established in simulink.According to the stator winding structure of the six-phase induction motor,a dual-three-phase grouped SVPWM scheme is proposed,and the entire six-phase system is divided into two three-phase subsystems to be designed respectively,and its feasibility is verified.Because the traditional six-phase SVPWM algorithm considers too few factors,unnecessary harmonic losses are generated,and the SVPWM algorithm of the intermediate vector is proposed,but the calculation amount of this synthesis method is too large.The improved intermediate vector SVPWM algorithm uses two vectors with opposite directions on the same horizontal line to synthesize the intermediate vector,so as to reduce the calculation of the angle in the synthesis process and further reduce the harmonic content.The three SVPWM algorithms are respectively combined with the direct torque control to realize the system combination.Through the comparison and analysis of the simulation results,it is concluded that the SVPWM direct torque control method with the improved intermediate vector can obtain the optimal harmonic suppression effect.In the direct torque control system,the stator flux linkage observation part and the sliding mode variable structure theory are combined to construct a reasonable sliding mode surface and control law,design the stator flux linkage sliding mode observer,and simulate it with the traditional voltage model Compared.Finally,use CCS3.3(Code Composer Studio 3.3)software to write the experimental program of SVPWM direct torque control system.On the motor platform,a comparative experiment between the traditional six-phase SVPWM algorithm and the improved intermediate vector SVPWM algorithm is carried out.The experimental verification shows that the improved intermediate vector SVPWM algorithm has better suppression effect on harmonics,and it has certain values in the industry.