Single stage high-frequency non-isolated step-up sinusoidal inverter with three ground-side power switches

Abstract

Conventional high-frequency non-isolated inverter is generally composed of two stages, the step-up stage and the voltage inversion stage, and independent control strategy must exert on each stage. In order to solve the shortcoming, a topological solution (L3 topology) is proposed in this letter, combining the structure of the boost topology and the improved Watkins-Johnson topology to a single stage, realizing voltage step-up and inversion with only three ground-side power switches and single control signal. Theoretical analysis and experimental results validate the feasibility. The merits include ease of driving, small port current ripple, high efficiency, simple control strategy and so forth.

Active PFC stage based on synchronous inverse Watkins-Johnson topology

“…Unbalanced winding of inductor ( ≠ ) has been discussed in paper [3], which makes the transfer ratio curve deviates from the median asymptote. One more control dimension can be therefore added for possible fine control.…”

Synchronous High Step-Down Ratio Non-Isolated LED Constant Current Driver Based on Improved Watkins-Johnson Topology

“…Nevertheless, several shortcomings include drive difficulty of the float switch, high input noise level, and complexity of primary inductor, hampers its applying. In order to overcome limitations of the WJ topology, the author of this paper have been proposed two approaches to improve the original WJ topology in recent previous works [12], [13], to realize dc/ac inverter, which will be collected and re-demonstrated in next section.…”