Research On Control Stratege For IPMSM Based On Electrolytic Capacitor-less

With the development of variable-frequency speed regulation technology,variable-speed AC motor system is widely used in household appliances.The traditional IPMSM drive and control system generally uses large electrolytic capacitor to compensate the voltage fluctuation of the bus.However,large electrolytic capacitors not only increase the difficulty of power converter miniaturization,but also limit the life of the system.In addition,in order to meet the power factor requirements of household appliances and the input current harmonics standard,the traditional drive system also includes PFC circuit,which increases the cost of the system.Therefore,the topology and control strategy of IPMSM control system with small capacitance thin film capacitance in bus link have become the research hotspot of many home appliance enterprises and universities.Firstly,this thesis aims to improve the grid-side power quality of the electrolytic capacitor-less control system,analyzes the characteristics of the busbar capacitance capacity and busbar voltage of the uncontrolled rectifier circuit,and obtains the relationship between the busbar voltage and the grid-side input power factor through theoretical analysis.Aiming at the problem of system power fluctuation,a closed-loop control method for the output power of the inverter is proposed.The controller combining proportional integral and proportional resonance is used to accurately follow the power signal,and the difficulty of adjusting the controller parameters is reduced by improving the controller,and the ideal control effect is achieved.Secondly,to solve the complex problem of power controller parameter tuning,a current setting strategy based on current tracking was proposed.The power control loop was removed,and the power of the inverter was controlled indirectly by controlling the current of the q-axis,so as to achieve a higher grid-side input performance.Aiming at the problem of insufficient output voltage margin of inverter,based on the premise of voltage limit and current limit,a d-axis current set scheme was designed.At the same time,voltage compensation strategy of dq axis based on bus voltage was adopted to reduce the bus voltage fluctuation and reduce the harmonic distortion rate of current on the grid side.Finally,the topology and control strategy of electrolytic capacitor-less system were verified by the Matlab/Simulink simulation platform and the motor towing experiment platform,and the simulation and experimental results were analyzed.There are 53 figures,2 tables and 86 references in this dissertation.