Devices such as power MosFETs and IGBTs cannot be used. Symmetric voltage should be used to block GTO and thyristor.
Equipment. Of course, series forward diodes can also be used to solve this problem.
The above is what I got from reading the literature. As can be seen from the above, if GTO and thyristor with symmetrical voltage blocking are used, series diodes are not needed, while power MosFETs and IGBTs need series diodes. The specific document is the doctoral thesis "Research on Z-source Inverter" of Zhejiang University. In the introduction, voltage source inverter, current source inverter and Z source inverter are compared. For reference, hope to adopt!