Research On Control And Application Methods Of New Matrix Converter

The matrix converter is a new type of direct AC-AC converter,which overcomes the shortcomings of the traditional back-to-back converter and has many advantages.However,matrix converter has problems such as low voltage transfer ratio and complicated modulation methods,which limits its industrial application.Therefore,research on control strategies of new matrix converters in different applications has become a hot topic in recent years.The multilevel matrix converter has a lower output total harmonic distortion rate,which can reduce the common mode voltage and improve the power density;the quasi-Z source matrix converter can improve the voltage utilization rate and reduce the difficulty of commutation.In view of the above two new matrix converters,this paper mainly studies related control strategies used in different applications.Firstly,the working principle of three level direct matrix converter and its indirect space vector modulation method are introduced in detail,and the simulation model is established to verify the correctness of the modulation method.Secondly,according to the topology of the three-level direct matrix converter,the input side of the three-level direct matrix converter is mathematically modeled.Combining input power and output voltage compensation methods under unbalanced input voltage,an input current control system with voltage compensation based on sliding mode control is proposed.At the same time,a simulation model was established and compared with the traditional PID control method to verify the superiority of the proposed method.Then,the circuit topology and voltage boost principle of the quasi-Z source two-stage matrix converter are introduced.Meanwhile,its indirect space vector modulation method with shoot through state is analyzed.Simulation results show that the two-stage matrix converter with quasi-Z source network structure has higher voltage utilization than the traditional two-stage matrix converter.Finally,the vector control system of quasi-Z source two-stage matrix converter-permanent magnet synchronous motor system based on passivitybased controller is studied.The principle of PID vector control of quasi-Z source two-stage matrix converter-permanent magnet synchronous motor system is briefly introduced,and a passivity-based control method based on interconnection and damping distribution is proposed to improve the dynamics performance of the system when given speed and torque changed.Comparative simulations are established to verify that the designed system can effectively improve system control performance.