A 1-MHz Series Resonant DC–DC Converter With a Dual-Mode Rectifier for PV Microinverters

Shen, Yanfeng; Wang, Huai; Shen, Zhan; Yang, Yongheng; Blaabjerg, Frede

doi:10.1109/tpel.2018.2876346

Cited by 65 publications

(28 citation statements)

References 56 publications

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“…In particular, at medium and low load currents, E of f is mainly determined by E oss due to the small E of f,V I . This is because the two-dimensional electron gas (2DEG) conducting channel of a GaN HEMT can be fast cut off before the voltage of the nonlinear output capacitance, i.e., v ds , rises significantly [52].…”

Section: A Swtiching Loss Breakdown Of Gan Hemtsmentioning

confidence: 99%

Desynchronizing Paralleled GaN HEMTs to Reduce Light-Load Switching Loss

Shen

Shillaber

Zhao

et al. 2020

IEEE Trans. Power Electron.

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Parallel connection of GaN high-electron-mobility transistors (HEMTs) is a more cost-effective or even an unavoidable solution to achieve higher current ratings. As the load decreases, however, the switching loss of paralleled HEMTs becomes dominant over the conduction loss, and the overall power conversion efficiency drops sharply. To reduce the light-load switching loss, this paper proposes a desynchronizable paralleling scheme. The midpoint (AC terminal) of each paralleled HEMT half bridge is connected with a commutation inductor, which thus, enables two operation modes: synchronous and asynchronous modes. The synchronous mode is activated at heavy loads to share the high current; the added commutation inductors lead to better current sharing than the direct parallel. When operating at light loads, however, the paralleled devices are desynchronized to generate a circulating current flowing through the commutation inductors. The circulating current enables the lagging HEMTs to achieve the zero-voltage switching (ZVS) and allows the leading ones to turn on at a current lower than the load, thereby significantly reducing the total switching loss. In addition, a thermal balancing scheme is proposed to alleviate the thermal stress imbalance between the desynchronized GaN HEMTs. The operating principle and design guidelines of the desynchronizable paralleling scheme are detailed. Finally, experimental results from multi-pulse and continuous tests of GaN HEMTs are provided to verify the advantages of the proposed paralleling scheme in reducing light-load switching loss and improving light-load efficiency.

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Section: A Swtiching Loss Breakdown Of Gan Hemtsmentioning

confidence: 99%

Desynchronizing Paralleled GaN HEMTs to Reduce Light-Load Switching Loss

Shen

Shillaber

Zhao

et al. 2020

IEEE Trans. Power Electron.

Self Cite

View full text Add to dashboard Cite

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“…Finally, the transfer functions can be formulated from the state-space small-signal AC model presented in (11), which leads to:…”

Section: Step 4: Calculating the Small-signal Ac Models And Transfer mentioning

confidence: 99%

“…The conventional series resonant DC-DC converter offers the advantage of high efficiency as it can operate with zero-voltage switching [1]. However, it is not able to regulate a wide input voltage range with a fixed-frequency phase-shift control [11]. Coupled inductor-based DC-DC converters with a clamp circuit have some features such as high voltage gain, high efficiency, leakage inductor energy recycling, and low voltage stress on the switches.…”

Section: Introductionmentioning

confidence: 99%

Modeling and Control Design of the Symmetrical Interleaved Coupled-Inductor-Based Boost DC-DC Converter with Clamp Circuits

et al. 2019

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The symmetrical input-interleaved high-gain DC-DC converters are suitable candidates to be used as the first stage in PV microinverters and as parallel-connected power optimizers. In both applications, they are responsible for boosting the PV module DC voltage to a higher value and executing the maximum power point tracking control. However, such converters have many state variables, some of them discontinuous, and many operation stages, which make the development of the small-signal model a challenging task. Therefore, the aim of this paper is to propose a reduced-order improved average method (ROIAM) to model the family member of converters that present characteristics such as symmetry, interleaved operation, and discontinuous state-space variables. ROIAM is applied to model for the first time in the literature the symmetrically-interleaved coupled inductor-based boost (SICIBB), leading to a fourth-order mathematical model (reduced-order model). The complete eighth-order mathematical model is developed as well to prove that the reduced-order model represents correctly the dynamic behavior of the SICIBB converter by employing only four state variables, reducing considerably the effort of the modeling. Based on the reduced-order proposed model, a closed-loop control is designed and tested in a 300-W prototype of the SICIBB converter.

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“…Such an arrangement can result in efficient operation with the most typical Si PV modules containing 60-and 72-cell ( Figure 2b). Recently, the variable dc-link voltage control was applied in several state-of-the-art two-stage microinverters [17,18] and battery chargers [19]. It resulted in higher efficiencies, extended reliability, and good compatibility with different PV modules [20,21].…”

Section: Link Voltage Control In Two-stage Pv Microinvertersmentioning

confidence: 99%

Photovoltaic Energy Yield Improvement in Two-Stage Solar Microinverters

et al. 2019

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The focus in this paper is on the two-stage photovoltaic (PV) microinverters using a buck-boost dc/dc front-end converter. Wide input voltage range of the front-end converter enables operation under shaded conditions but results in mediocre performance in the typical voltage range. These microinverters can be controlled with either fixed or variable dc-link voltage control methods. The latter improves the converter efficiency considerably in the range of the most probable maximum power point (MPP) locations. However, the buck-boost operation of the front-end converter results in noticeable variations of the efficiency across the input voltage range. As a result, conventional weighted efficiency metrics cannot be used to predict annual energy productions by the microinverters. This paper proposes a new methodology for the estimation of annual energy production based on annual profiles of the solar irradiance and ambient temperature. Using this methodology, quantification of the annual energy production is provided for two geographical locations.

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A 1-MHz Series Resonant DC–DC Converter With a Dual-Mode Rectifier for PV Microinverters

Cited by 65 publications

References 56 publications

Desynchronizing Paralleled GaN HEMTs to Reduce Light-Load Switching Loss

Desynchronizing Paralleled GaN HEMTs to Reduce Light-Load Switching Loss

Modeling and Control Design of the Symmetrical Interleaved Coupled-Inductor-Based Boost DC-DC Converter with Clamp Circuits

Photovoltaic Energy Yield Improvement in Two-Stage Solar Microinverters

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