大功率变流技术与应用（四）——升-降压逆变器

采用一级电路结构的阻抗源逆变器（Z-源逆变器），可以克服电机调速系统或分布式发电联网接口中的许多实际问题。阻抗源逆变器除了实现一级变换外，还能够做到：（1）不管输入电压多高，都能产生任一所希望的、甚至比网压高的输出交流电压，从而减少电机的额定电流；（2）在网压下陷期间无需任何附加电路，就能提供“安度难关”的能力；（3）改善功率因数，减少电流谐波和共模电压。阻抗源变流器将为太阳能发电和燃料电池提供简单、便宜、可靠的单级变换装置，也就是为传动系统提供了另一种选择。

High Power Converter Technology and Application(4)——Buck-Boost Inverter

Impedance Source Inverter (Z-source Inverter) with primary circuit structure is applied to eliminate the defects of motor speed-modulation system and distributing power generation network interfaces. Moreover,Z-source Inverter has the advantages of (1) producing anticipative output AC voltage even higher than net voltage to reduce rated current for motors;(2) breaking through the difficulty without any circuit during net voltage drop;(3)improving power factor,reducing current harmonics and common-mode volta...