Research On Vector Control Of Double Y Shift 30° Six-phase Permanent Magnet Synchronous Motor And Its Fault Tolerant Technology

With the rapid development of electric drive technology,inverter power supply is adopted in most motor control systems,which limits the number of phases of the motor not to be a limitation.Compared with three-phase motors,multiphase motors are widely used in applications with high reliability,low voltage,high power and precise transmission due to their small torque ripple and good fault-tolerant performance.In this paper,the dual-Y shift 30° six-phase permanent magnet synchronous motor is taken as the research object,and its vector control technology and fault-tolerant control strategy are deeply studied.Firstly,the mathematical model of the motor is established.The mathematical model of the motor under the six-phase stationary coordinate system is analyzed.According to the vector space decoupling principle,the transformation matrix of the motor under different coordinate systems is derived and the motor model is decoupled.Secondly,focus on the vector control system of the motor.The correctness of the model is verified by traditional current hysteresis control.Although the voltage modulation factor of two-vector SVPWM is higher than that of four-vector SVPWM,it can not control the current component in the harmonic plane,which leads to a large amount of harmonic in the output current wave.In this paper,a four-vector SVPWM algorithm based on the intermediate voltage vector is used to vector control the six-phase motor.The waveform is symmetrically processed centrally to reduce the switching frequency of the power tube under the premise of minimizing the stator copper loss.Thirdly,the paper analyzes the magnetic potential and torque of the two states of normal operation and Z-phase open-circuit operation,and studies the fault-toleranttechnology based on the principle of the same magnetic potential.When phase Z is open,the residual phase current is optimized for the minimum stator copper loss and the maximum output torque,and the relationship between the harmonic planar currents is obtained through Matlab Optimal Toolbox.In order to improve the current tracking characteristics,an improved digital current hysteresis mode.The use of digital signal processor programmable features,so that the motor running under normal operation and lack of phase operation of two different states to select the corresponding control mode to achieve the motor in the event of phase failure can continue without stopping the steady operation.Finally,the article designs the control system of six-phase permanent magnet synchronous motor,proposes the hardware design scheme,draws the software flow chart according to the working principle of the system,and builds the experimental platform to verify the feasibility of the system.