Aalborg inverter — A new type of “Buck in Buck, Boost in Boost” grid-tied inverter

This paper presents a new family of high efficiency DC/AC grid-tied inverter with a wide variation of input DC voltage. It is a kind of “Boost in Boost, Buck in Buck” inverter, meaning that only one power stage works at the high frequency to achieve the minimum switching loss. Furthermore, the minimum filtering inductance in the power loop is achieved to reduce the conduction power loss whether in “Boost” or “Buck” mode. In theory, it can achieve higher efficiency than other inverters under the same condition of input DC voltage. The principle of operation is fully illustrated through the analysis on the equivalent circuits of a “three-level” single-phase inverter. Simulations show it has good control performance.