Research on Shoot-through Zero Vector of Impedance Source Linearization Control Strategy

摘要

Z-source inverter takes advantage of a distinctive impedance source network and modulation method of shootthroughvector, and achieves the function of buck/boost DC - AC inverter in the single stage system at the same time,which is suitable for grid-connected PV systems with large input voltage variations. The purpose of this study is to draw aunified method of shoot-through vector and grid inverter of the z-source inverter, apply the method of state-space averagingfor the modeling analysis of the z-source inverter and give a complete mathematical model. Based on which and accordingto the nonlinear control theory and making use of the linearization of affine nonlinear model of the z-source inverter,we can get the specific derivation of equation. The results of the simulation and experiment show that according tothe linearization of the shoot-through vector with affine nonlinear model for the z-source, we can make the system havethe characteristics of fast and accurate tracking, small overshoot, small DC voltage, AC current ripple and small THD, andit has a certain practical value.