Micro-Decoupling Control Of Five-Phase Hybrid Stepping Motor

Five-phase hybrid stepping motor has a unique application prospect in the field of low-speed positioning due to its advantages such as small size,low cost,high positioning accuracy and no accumulative error.However,in the traditional full-step operation mode,the larger step angle will cause obvious torque ripple and loud noise.In addition,the mutual inductance between stator windings makes its mathematical model complex,and the difficulty of further reducing step angle is greatly increased.In view of the above problems,this paper studies a five-phase hybrid stepping motor micro-decoupling control algorithm,which can effectively reduce the motor step angle.The following jobs are achieved.Firstly,the operating principle and mathematical model of five-phase hybrid stepping motor are studied in depth.Accurate inductance parameters are obtained by magnetic circuit method,and a highprecision mathematical model is established,which provides theoretical basis for stator current ripple analysis and micro-decoupling control algorithm under different main circuits.Secondly,based on the establishment of high-precision mathematical model and the maximum value of absolute value of current rate of change as the index,the stator current ripple of three main circuits is analyzed quantitatively.Combining the two angles of current ripple and feasibility of differential operation,the scheme of five-phase half-bridge star connection to the main circuit is selected,and a micro-decoupling control algorithm based on current hysteresis vector control is studied under the main circuit,which can effectively reduce the step angle of five-phase hybrid stepping motor.Thirdly,the simulation model of the system is established by MATLAB/Simulink,and the current ripple sizes of stator windings under different main circuits are simulated,analyzed and compared,as well as the simulation verification of the micro-decoupling control algorithm under the five-phase halfbridge star connection main circuit.Finally,the hardware system and software system of the differential drive system of the five-phase hybrid stepping motor are described.At the same time,the experiment verifies that the microdecoupling control algorithm studied in this paper can effectively reduce the step angle of the motor,suppress the torque ripple and significantly reduce the rotational noise.