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This paper develops a novel single-switch resonant power converter for renewable energy generation applications. This circuit topology integrates a novel single-switch resonant inverter with zero-voltage switching (ZVS) with an energy-blocking diode with zero-current switching (ZCS). The energy-blocking diode with a direct-current output filter filters the output stage of the novel single-switch resonant inverter. Only one active power switch is used for power energy conversion to reduce the cost of active power switches and control circuits. The active power switch is controlled by pulsewidth modulation at a fixed switching frequency and a constant duty cycle. When the resonant converter is operated at discontinuous conduction mode, the inductor current through the resonant tank could achieve ZCS of the energy-blocking diode. Accordingly, a high energy conversion efficiency is ensured. Operating principles are derived, and analyses are carried out based on the equivalent circuits for the proposed power converter under different operating modes. The operating principles of the converter were verified using a 32.4-W 70-kHz experimental photovoltaic-powered load system. Given appropriately chosen circuit parameters, the active power switch can be operated with ZVS, and a measured energy conversion efficiency of the proposed topology of 97.3% can be achieved. Experimental results demonstrate a satisfactory performance of the proposed topology, which is particularly suited to the energy conversion applications in renewable energy generation systems. [ABSTRACT FROM PUBLISHER]

In this paper, analysis of circulating currents of paralleled single-phase boost converter systems is presented. The dc loop and ac loop circulating currents are clearly explained. In order to eliminate the dc loop circulating currents and reduce switching losses, a simplified pulsewidth modulation strategy is adopted in a paralleled single-phase boost converter. Based on the analysis of circulating currents, common-mode circulating current (CMCC) and differential-mode circulating current (DMCC) are defined. Then, CMCC and DMCC compensators are proposed in a centralized control scheme to reduce the common-mode and differential-mode circulating currents in a parallel system operated in both rectifier and inverter modes with different power sharing for microgrid applications. Converter-paralleled system stability analysis is also presented. Finally, a prototype system is constructed to facilitate the theoretical results as verification. From the experimental results, the proposed control scheme can indeed reduce the circulating currents under equal and/or different power rating conditions in the parallel system. [ABSTRACT FROM PUBLISHER]

Among the many advantages that resonant power conversion has over conventionally adopted pulse-width modulation include a low electromagnetic interference, low switching losses, small volume, and light weight of components due to a high switching frequency, high efficiency, and low reverse-recovery losses in diodes owing to a low di/dt at switching instant. This work presents a novel loaded-resonant converter for direct currennt (dc)-to-dc energy conversion applications. The proposed topology comprises a half-bridge inductor-capacitor-inductor (L-C-L) resonant inverter and a bridge rectifier. Output stage of the proposed loaded-resonant converter is filtered by a low-pass filter. A prototype dc-to-dc energy converter circuit with the novel loaded-resonant converter designed for a load is developed and tested to verify its analytical predictions. The measured energy conversion efficiency of the proposed novel loaded-resonant topology reaches up to 88.3%. Moreover, test results demonstrate a satisfactory performance of the proposed topology. Furthermore, the proposed topology is highly promising for applications of power electronic productions such as switching power supplies, battery chargers, uninterruptible power systems, renewable energy generation systems, and telecom power supplies. [ABSTRACT FROM AUTHOR]

A novel microprocessor-controlled electronic ballast with a class-E resonant inverter for illumination applications is employed to link a photovoltaic (PV)-powered battery energy storage system (BESS) as a main power source with a utility ac power as a complementary source. The proposed strategy aims to control power flow either from the PV-powered BESS or from the utility ac power line to the electronic ballast. This novel design has lower loss, easier control, and higher efficiency than traditional PV panel has. A 27-W fluorescent lamp is ignited by electronic ballast with a class-E topology to validate the proposed theoretical analyses. When the electronic ballast is driven by the PV-powered BESS and the utility ac power, overall efficiency of the proposed system is 94.2% and 91.1%, respectively. Experimental results demonstrate the functionality of the overall system, indicating that it is a good solution for several hybrid-source applications. [ABSTRACT FROM PUBLISHER]

This paper presents a novel application of half-bridge series–parallel resonant converter (HBSPRC) for dc source and secondary battery interface. The converter practically eliminates both low- and high-frequency current ripple on the battery, thus maximizing battery life without penalizing the volume of the charger circuit. Moreover, operation above resonance is preferred, because the power switches turn on at zero current and zero voltage; thus, the freewheeling diodes do not need to have very fast reverse-recovery characteristics. The proposed battery charger circuit has few components and low-energy conversion loss, which enhance the system's overall efficiency. Circuit operation modes are determined from the conduction profiles. Operating equations and an operating theory are also developed. Experimental results based on a 12-V 48-Ah battery charger are proposed to validate the analysis and to demonstrate the performance of the proposed approach. The maximum charging efficiency of the proposed topology during the overall charging period is 93.98%. Satisfactory performance is obtained from the measured results. [ABSTRACT FROM AUTHOR]