Juan Antonio Aqui-Tapia

Current source topologies have several advantages compared to conventional voltage systems. Their inherent voltage-boosting function, intrinsic short-circuit protection, no electrolytic capacitor, direct-current control, continuous input current, and high reliability make them exceptional candidates for power generation systems, particularly for photovoltaic applications. This study provides an overview of the current source topologies for multi-stage photovoltaic grid-connected systems by comparing the number of components, performance, power-decoupling techniques, efficiency, and frequency operation. The overview reveals gain, performance, energy quality and lifetime improvements, thereby providing current source systems as an attractive alternative for renewable applications.

The study of this article mainly focuses on the assessment and performance of current and voltage inverters in ozone generation, applying power density modulation (PDM) and typical operation. The topologies designed were a voltage-source full-bridge inverter (VSFBI), a current-source full-bridge inverter (CSFBI), and a CSFBI without considers the PDM. The inverters were analyzed and implemented considering an inductor-capacitor-capacitor (LCC) series-parallel resonant tank for the VSFBI and an LC parallel resonant tank for the CSFBI. The duty cycle impact ( D _m ) of the modulation signal was analyzed, and all inverters were compared. Based on the results, the decrease in D _m allows increasing the ozone generation because of avoiding the dissociation of the ozone molecules. The maximum concentration and efficacy presented by the VSFBI in ozone production were 620 gr/m ³ and 0.155 gr/min. Also, the maximum electrical efficiency was 91%; it was presented by the CSFBI without PDM.

In this article, a novel high-power-factor electrolytic-capacitorless light-emitting diode (LED) driver based on the use of a ripple port is presented. The ripple port consists of adding an extra power processing circuit at the output of the converter that injects energy to compensate for the output current and voltage ripples. In this work, the main converter is built by using a flyback converter operating in the discontinuous conduction mode (DCM). The ripple port is implemented by adding an extra winding to the flyback coupled inductors, together with an extra switch, a capacitor, and an inductor. The additional switch is used to inject energy to the output in the time intervals, in which the flyback output current is low, thus reducing the output current ripple. The proposed converter is analyzed in detail, and a design methodology is proposed. A design example for a 27-V/1-A LED lamp is presented. Simulation and laboratory experiments have also been carried out. It is demonstrated that the proposed solution can achieve a reduction on the output current ripple of around 65% compared to the solution without ripple port for the same total capacitance and maintain a high power factor of 0.994.