Research On Enhanced Quasi-Z Source Inverter

With the shortage of global energy and environmental pollution is becoming more and more serious,more and more countries pay attention to the development and utilization of new energy,such as wind and solar energy.As a new type of inverter,the Z source inverter overcomes the limitations of the traditional voltage source inverter and has a good application prospect in the field of new energy sources.However,the Z-source inverter also has some problem such as insufficient boosting capacity and the high voltage of the capacitor.Improving the performance of Z-source inverter is beneficial to the promotion and application of Z-source inverter.In view of the problems existing in the Z source inverter,this paper improves the topology of the inverter,and studies the improved Z source inverter.The work and the research results are as follows.The high boost capability is an important prerequisite for the Z-source inverter to be applied to the low-voltage input situations.Based on the analysis of the topology of the Z-source inverter and its boosting ability,this paper proposes a method of cascade switching inductance to improve boost ability of Z-source inverter.On the basis of the switching inductor quasi Z source topology,cascade type I and type II switched inductor to be enhanced I/II quasi Z source inverter.Compared with the switched inductor quasi Z source inverter,under the same direct duty cycle,the DC link voltage of enhanced quasi Z source inverter is higher,which can effectively improve the boost capability of the inverter.At the same time,on the basis of the same number of devices,the type II enhanced quasi Z source topology has more advantages in improving the boost factor of the inverter,So select type II enhanced quasi Z source inverter as the following focuses on "enhanced quasi Z source inverter".Then,this paper studies the characteristics of the enhanced quasi Z source inverter,and points out that under the same boost factor,the superiority of the enhanced quasi Z source inverter in capacitor voltage stress and inductor current ripple,the correctness of theoretical analysis is verified by simulation.At last,this paper builds the experiment platform of enhanced quasi Z source inverter,designed the main circuit and control circuit,introduces the design process of the controlsoftware,The experimental results verify the feasibility and superiority of the enhanced quasi Z source inverter..