Research On Model Predictive Control Of Permanent Magnet Synchronous Motor Driven By Three-phase Six-switch Fault-tolerant Inverter

The unrestrained consumption of fossil energy in modern human society has brought energy crisis and serious environmental pollution problems.Therefore,electric vehicles that don’t consume fossil energy have become a research hotspot,especially the core of permanent magnet synchronous motor(PMSM),Although PMSM has a good development prospect,how to effectively control and ensure the safety and stability of the whole motor control system is still the primary problem to be solved.Control algorithm,inverter and sensor are indispensable parts of PMSM drive control system.How to increase the practicability of advanced control algorithm and reduce the failure rate of inverter and sensor is very important for the stable and high-performance operation of motor drive control system.Therefore,this paper designs and applies a new three-phase six-switch fault-tolerant inverter to the improved PMSM model predictive torque control system to achieve ideal control.The main research contents are as follows:(1)The basic principles of various control algorithms of PMSM in existing research are analyzed and introduced;different fault-tolerant topologies of traditional common fault-tolerant inverters are analyzed and compared,and their respective advantages and disadvantages are compared;basic operating principles of PMSM such as internal structure,mathematical model and coordinate transformation are analyzed,which lays a theoretical foundation for subsequent research and design.(2)The traditional MPTC weight factor adjustment and optimal voltage vector cause a large amount of calculation.To solve this problem,the traditional algorithm is improved,the minimum value function is redesigned,the vector selection scheme is improved,the computational load of the algorithm is reduced,and the algorithm practicability is increased.Secondly,aiming at the speed controller in the system,the shortcomings of traditional PI,sliding mode and other controllers are analyzed.A new type of adaptive non-singular terminal sliding mode controller(ANFTSMC)is designed from the aspects of increasing the adaptive capability and improving the approaching rate.A new ESO disturbance observer is designed for the controller.Finally,it is combined with the improved MPTC to increase the speed and stability of the system.(3)In order to overcome the drawbacks of large size,high cost and unstable output commonly used in traditional fault-tolerant inverters,a new fault-tolerant topology scheme is designed,and a new three-phase six-switch fault-tolerant inverter is obtained,which is used to drive PMSM,realize fault-tolerant control and improve the fault-tolerant efficiency and stability of the system.(4)For the speed information feedback sensor part of PMSM drive control system,in order to reduce the failure rate of the mechanical sensor and improve the fault tolerance of the system as a whole,an improved ESO algorithm is used to design the ESO speed and position observer for speed sensorless control.Finally,the MPTC speed sensorless control system for PMSM driven by three-phase six-switch fault-tolerant inverters is built.