Research On Fault Compatible And False Control Of Six-phase Permanent Magnet Synchronous Motor

Permanent magnet synchronous motors have the advantages of high precision,small size,and good speed control performance.Compared with traditional multi-phase motors,they have the advantages of high efficiency and high power factor.Therefore,they are widely used in high power level and high reliability occasions of industrial,military and national life.In some special applications,the system cannot be downed and has certain fault tolerance.Therefore,research on fault-tolerant control of multi-phase permanent magnet synchronous motors will having practical value.In this paper,six-phase permanent magnet synchronous motor is taken as the research object,the mathematical model of the six-phase permanent magnet synchronous motor is built,and analysis the change of the magnetic motive force when one phase open circuit.After the fault,adopt the principle of equal magnetic motive force to implement fault compensation,so that the motor continues to run.Firstly,the structure and working principle of the six-phase permanent magnet synchronous motor are introduced,and the transformation relationship between the six-phase stationary coordinate system and the two-phase rotating coordinate system is explained,simultaneously,obtain the transformation matrix.Use the control method of i_d=0 based on the Field Oriented Control,establishing the proportional relationship between the electromagnetic torque and the quadrature-axis current component i_q.The system adopts the double closed-loop PI control of the speed loop and the current loop,and the six-phase permanent magnet synchronous motor control system is built in MATLAB/Simulink and a simulation experiment is conducted.Secondly,analysis and research on the single-phase open-circuit fault of six-phase permanent-magnet synchronous motor.Analyze the distribution of magnetic motive force after the failure,and establish the principle that the stator magnetic motive force of the motor is unchanged before and after the fault.By controlling the phase and amplitude of the remaining phase winding currents after the fault,the total magnetic motive force of the remaining stator is equal to the magnetic motive force before the fault.After the fault,the current hysteresis control method is adopted so that the system can quickly track the set current to achieve the effect of rapid compensation,and fault tolerant simulation is built in MATLAB/Simulink.Finally,a six-phase permanent magnet synchronous driver take TMS320F28335 chip as the core is designed.The driver includes an inverter module,a PWM driver module,a switching power supply module,a current detection and a protection circuit module.