Study On Speed Control System Of Permanent Magnet Synchronous Motor Based On Two-stage Matrix Converter

The permanent magnet synchronous motor has wide application in the industrial field because of its simple structure,high power factor,small volume,large torque-current ratio,small moment of inertia,easy heat dissipation and easy maintenance.The two-stage matrix converter evolves from the topology of a conventional matrix converter.It has the advantages of adjustable input factor,bidirectional flow of energy,no large-capacity energy storage components,compact structure,and the like,and is compared with the conventional matrix converter.The commutation strategy and control strategy of the two-stage matrix converter are simpler,easier to implement,and have good research and development prospects.In this paper,the speed control of permanent magnet synchronous motor based on two-stage matrix converter is studied,and the precise control of the speed of permanent magnet synchronous motor is realized by using vector control algorithm.In this paper,the modulation principle and topology structure of conventional matrix converter are discussed firstly,and then the two-stage matrix converter topology which is easier to realize is deduced.Secondly,the control mode of two-stage matrix converter with zero-and no-zero vector modulation is analyzed,and the feasibility of the two-stage matrix converter is verified by software simulation combined with inverter stage SVPWM modulation technology.On this basis,the vector control simulation model of permanent magnet synchronous motor based on two-stage matrix converter is established,and the dynamic performance of speed,current and electromagnetic torque of the speed regulating system is analyzed under the conditions of starting,braking,variable speed and variable load,etc.At the same time,the energy feedback of motor braking is analyzed in detail.Based on the above research,this paper also builds a model based on DSP automatic code generation.The discrete software algorithm transforms the successfully verified software simulation model into a purely discrete control model,so that the system can automatically generate C language that can be executed by DSP chip.The code reduces the writing of a lot of cumbersome code,speeds up the cycle of system development,and finally verifies the feasibility of automatically generating a code scheme through experiments.Finally,the hardware system design of the permanent magnet synchronous motor speed control system based on two-stage matrix converter is carried out,including the drive circuit,detection circuit,control circuit and filter circuit.The function of each hardware circuit diagram is analyzed.The practical application in industry has laid a certain foundation.