Research On Active Quasi-Switching Capacitor Inverter Based On Switching Inductance

In recent years,impedance source inverters have developed rapidly,and are widely used in the field of motor drive with their unique buck-boost characteristics.In the motor drive system,when the DC bus voltage drops,the boosting characteristic of the impedance source network can maintain the output voltage of the inverter at the original level to ensure stable operation of the system.Therefore,studying impedance source inverters is of great significance.Firstly,the traditional Z source and quasi-Z source networks are studied,mainly from the aspects of topology,working principle and parameter calculation.The Z source and quasi-Z source inverters were simulated and verified in MATLAB/Simlink,and the experimental platform was built to verify the correctness of the theoretical analysis.Secondly,a switched-inductive active quasi-switched capacitor inverter(SLSC-qSBI)is proposed.The impedance source inverter is mainly studied from the working principle,voltage gain and parameter calculation.Subsequently,the active quasi-switching capacitor inverter based on switching inductors was extended,which was extended to switched capacitor expansion and switching inductor expansion,and the working principle of the two extended types was analyzed.The simulation verification was carried out by using MATLAB/Simlink,and the experimental platform was built to verify the experiment,which proved the correctness of the analysis.Thirdly,a comparative study on the pass-through modulation strategy of the impedance source inverter is carried out.The working principle of simple boost through modulation,maximum boost through modulation and maximum constant through-boost modulation is analyzed.Based on the switching inductor active quasi-switching capacitor inverter,the voltage boost and the voltage stress of the switching tube are deduced.Finally,these three pass-through modulation strategies are applied to the switching-inductive active quasi-switching capacitor inverters,and the experimental verification is carried out,which proves the correctness of the theoretical analysis.Finally,the mathematical model of permanent magnet synchronous motor and switching inductor active quasi-switching capacitor inverter is established,and the design of closed-loop control system is completed.The whole system was built with MATLAB.The experimental results show that the DC link voltage remains stable under the condition of DC bus voltage drop,and the permanent magnet synchronous motor control system can maintain stable operation.