Space-vector-modulated three-level Z-source hybrid direct AC-AC power converter

The addition of Z-source components into the "source" of standard converters enables a boost functionality without the need for additional switch. This relatively recent conversion concept can be extended to the three-level two-stage matrix converter by inserting a single Z-source network into its intermediate dc-link. The topology formed is, therefore, physically not very different. However, its modulation is not very straightforward if advantages like voltage buck-boost flexibility, minimum commutation count, and sinusoidal supply and load quantities are to be achieved simultaneously. This paper presents the principles of operation and the modified space vector modulation strategy that can achieve the above-mentioned advantages of the three-level Z-source hybrid direct ac-ac power converter as an attractive topological alternative for ac-ac buck-boost energy conversion. The findings presented here have been verified in simulations while experimental validation is currently under development.