| Traditional Static inverters with high frequency link exhibit many advantages, but usually they transfer power though two stages circuit structure. As a result, conversion efficiency, power density and reliability can hardly meet the requirements of electric apparatus gradually. As switching frequency is higher, ideal conversion efficiency can be kept by soft switching. Unfortunately,the effect of soft switching is limited when switching frequency is too high. Consequently, seeking novel kind of single-stage static inverter topology to improve general system performance will be a significance work for researchers.When isolated bi-directional DC-DC converter (BDC) is employed in static inverter, it brings a lot of advantages, which not only achieves electric isolation, strengthens the ability of accommodating to varied load,but also simplify circuit topology. Based on the analysis of the circuit structure and operation principle of static inverter which employed BDC, circuit topology family of single-stage Buck type and single-stage Buck-Boost type static inverter are given in this thesis, and also their control schemes. The simplest circuit topology, single-stage Flyback static inverter is chosen as typical research object. And after carefully analyzing operation principle of the static inverter, the design formula for key circuit parameter and the control scheme with instance output voltage feedback are given.The feasibility of the static inverter and the correctness of the theory analysis are verified through computer simulation. In addition, a single-stage Flyback static inverter of 500VA 270V DC/115V400Hz AC is designed. The experiment results show that single-stage Flyback static inverter achieve single-stage power conversion, process simpler circuit topology, has high reliability, and exhibits powerful ability of accommodating to varied load, which conquers the defects of traditional inverters. |
