A high-efficient LLCC series-parallel resonant converter

Abstract

Abstract-A high efficient LLCC-type resonant dc-dc converter is discussed in this paper for a low-power photovoltaic application. Emphasis is put on the different design mechanisms of the resonant tank. At the same time soft switching of the inverter as well as the rectifier bridge are regarded. Concerning the design rules, a new challenge is solved in designing a LLCCconverter with voltage-source output. Instead of the resonant elements, ratios of them, e.g. the ratio of inductances L s /L p is considered as design parameters first. Furthermore, the derived design rule for the transformer-inductor device fits directly into the overall LLCC-design. Due to the nature of transformers, i.e. the relation of the inductances L s /L p is only a function of geometry, this design parameter is directly considered by geometry. Experimental results demonstrate the high efficiency.

Two novel techniques for increasing energy efficiency of photovoltaic-battery systems

“…Tables 3 and 4 compared the PV-battery power source implemented using the proposed DC/PWM charger and decomposed PV panel with the usual PV-battery power sources implemented using the existing conventional DC/DC converters such as integrated circuit TL1510. As another comparison, the experimental results related to the maximum efficiency and converted power of the proposed DC/PWM charger and all the available DC/DC converter topologies used in grid-connected PV systems [45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60] are reported in Table 5. Comparing the experimental data explicitly verifies that the proposed DC/PWM charger has even higher efficiency compared to all the other DC/DC converters, and furthermore, there is no limitation for the maximum power converted by the proposed DC/PWM charger because it does not use inductors and capacitors that limit the converted power.…”

High efficiency high step-up DC/DC converters - a review

“…LLCC converter [25] is a good example of converters that merges the requirements of high efficiency and voltage gain.…”

A Comprehensive Review of DC–DC Converter Topologies and Modulation Strategies with Recent Advances in Solar Photovoltaic Systems

“…There are many varied approaches that were studied recently to overcome the problem of efficiency optimization when operated over the wide input voltage range. For instance, in [265] the more efficient multi-resonant DC-DC converter was designed that was illustrated in Figure 20. Though its structure is complex, during the design of the resonant tank, the converter has the minimum number of the external discrete components.…”