Research On Z Source Inverter Control And Application

Starting with the analysis of the limitations of traditional inverter, this paper has studied a new type inverter named Z-source inverter, which introduces a unique impedance network (Z-network) on the foundation of the traditional voltage source PWM inverter to form a new topology and get some new features lacking in the traditional inverter. The main contents are shown as following:1. On the basis of the Z-source inverter topology, this paper analyzed the working principle, commutation process and operating waveform of each unit of the three-phase voltage mode Z-source inverter in detail. Comparing with traditional inverter, the advantages and disadvantages of Z-source inverter are summarized. From above work, a comprehensive understanding of the voltage mode Z-source inverter's characteristics can be obtained.2. Multianalysis Z source inverter SPWM and the SVPWM modulation principle, and carried on the simulation experiment to each modulator approach, the simulation result has carried on the comparison.3. Switching function and duty cycle method can be used to built the mathematical model of three-phase Z-source inverter. The author used the methods and proposed the control strategy which can acquire stable Z-network capacitor voltage and decoupled d-q axis current. And the controller of Z-source inverter system for grid-connected was designed. Finally, the accuracy of theoretical analysis and the validity of control strategy have been verified by the simulation results.