Three winding coupled inductor based high boost inverter with increased gain control

Renewable sources like solar PV, fuel cell, etc., needs high boost inversion in order to connect to utility supply due to their low output voltage nature. Apart from high gain, some other desirable features of the inverter are low component count, high efficiency, low footprint, immunity to spurious signals like EMI. In this paper a three winding coupled inductor based inverter topology is presented which can provide a very high voltage boost by utilizing the shoot through of its inverter legs. The proposed inverter uses only one coupled inductor, one capacitor as passive components in its structure which makes it suitable for renewable applications. Generally coupled inductor based topologies provide increased gain at the expense of increased coupled inductor turns ratio beyond unity, but the gain of the proposed inverter can be made higher by increasing the tertiary to primary winding turns ratio from zero to unity. The gain can be also increased by increasing tertiary to secondary winding turns apart from increasing shoot-through duty and modulation index. Thus the proposed inverter provides more variables to control gain. The paper presents the detailed steady-state analysis of the proposed inverter and establishes the relation between their input-output variables. The operation of the inverter is validated by the experimental results.