扩展升压Z源逆变器及其控制策略的研究

Study of the Expended-boost Z-source Inverter and Its Control Strategy

Z源逆变器的Z源升压网络以其独特的优点正逐步取代前级buck-boost电路,成为逆变器研究的热点。但Z源升压网络升压范围有限。因此,在一些需要较高电压的应用领域Z源逆变器的应用受到了一定的限制。详细分析了一种扩展升压逆变器的工作原理,并引入了3次谐波注入调制策略,通过与传统简单升压控制策略的比较,验证了3次谐波注入调制策略在相同电压增益下能有效减小直流电压应力和电容电压,调制度相同时能大大提高逆变器的输出电压。仿真分析验证了上述结论。

Now Z-source inverter is replacing buck-boost circuit for its advantages and becoming a research focus. But as all the boost circuit, Z-source boost network is limited in boosting voltage,which limit its use in some fields that need very high voltage. A kind of expended-boost Z-source inverter was analyzed in detail. What＇s more,the third harmonic injection control strategy of expended-boost Z-source inverter was investiga- ted. Compared with the simple boost strategy and show the advantages of third harmonic injection control strat- egy in boosting the output voltage and reducing voltage stress and capacitor voltage under the same voltage gain. Simulation results demonstrate the theoretical analysis.