Transformerless Photovoltaic Grid-Connected Inverters

Xiao, Huafeng; Wang, Xiaobiao

doi:10.1007/978-981-15-8525-8

Cited by 6 publications

(4 citation statements)

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“…The filter is LCL-type, which consists of the NPC-side inductor L 1 , the filter capacitor C f and the grid-side inductor L 2 . C dc1 , C dc2 are split DC capacitors, and point-N is linked to the neutral-point of the clamping diode D 1 , D 2 [14]. u g is the grid voltage, and L g is the grid impedance.…”

Section: Conventional Active Damping Scheme Of Lcl-filtered Invertermentioning

confidence: 99%

Control scheme based on capacitor voltage second-order complex-vector feedforward for LCL-filtered inverter

Yang

2021

E3S Web Conf.

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For an inverter with LCL filter, voltage at the point of common coupling (PCC) is equivalent to the filter capacitor voltage in practical applications. However, the PCC voltage background harmonics will cause the distortion of grid current. Some problems exist in the traditional methods for harmonics suppression, such as insufficient phase margin, increasing design complexity and computation burden. Thus, a scheme of second-order complex-vector feedforward (SOCVF) of capacitor voltage is proposed in this article. First, based on the vectorial principle, the active unit vectors of capacitor voltage were calculated. Then, its fundamental component was obtained by the SOCVF-function. Furthermore, the references of the grid current were obtained with the instantaneous power theory. Hence, the proposed scheme helps effectively dampen the LCL resonance to make the system stable, and works well at suppressing the injected grid current distortion simultaneously. Simulation and experimental results validated the effectiveness of the proposed scheme.

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Section: Conventional Active Damping Scheme Of Lcl-filtered Invertermentioning

confidence: 99%

Control scheme based on capacitor voltage second-order complex-vector feedforward for LCL-filtered inverter

Yang

2021

E3S Web Conf.

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“…However, the lack of electrical isolation leads to the problem of leakage current. The leakage current increases system loss, causes electromagnetic interference, affects normal operation of other equipment, and even endangers personal safety [2], [3].…”

Section: Introductionmentioning

confidence: 99%

Topology Optimization Analysis of Leakage Current Suppression in Three-Level Four-Leg Photovoltaic Grid-Connected Inverter

Yang

Gao

2023

IEEE Access

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The grid-connected non-isolated photovoltaic inverter system suffers from the leakage current, which increases the loss of the system, and the grid-connected current harmonics impact the normal operation of the equipment. To this end, first, the leakage current mechanism in a conventional three-phase three-level four-leg grid-connected inverter is analyzed and two circuit topology improvement schemes are proposed. Second, mathematical modeling of different circuit topologies is carried out. With the leakage current and the harmonic distortion rate of the grid-side current as the main suppression indicators, the advantages and disadvantages of each topology are analyzed. Finally, the optimal leakage current suppression circuit topology is proposed for the three-level four-leg grid-connected inverter. Meanwhile, the corresponding objective function and constraints are constructed to solve the problem of selecting key components parameter by non-linear programming. Without additional control strategy, the proposed optimal circuit topology has a significant leakage current suppression performance compared to the other three topologies, only 10.24% of the conventional topology, and ensures that the grid-connected current total harmonic distortion rate meets the highest relevant standards.INDEX TERMS Three-phase four-leg inverter, three-level inverter, photovoltaic system, topology optimization, leakage current.

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“…Inversores sem transformador do tipo fonte de tensão, com filtro de saída do tipo LCL (indutor-capacitor-indutor), vêm sendo amplamente empregados para a obtenção de baixas perdas de conversão, redução de volume, peso e custo (RUAN et al, 2018), (BIERHOFF;SOLIMAN;ESPINOZA C, 2020), (KHAN et al, 2020), (XIAO;WANG, 2021), (XIAO, 2021), (BOLSI et al, 2021).…”

Section: Motivação E Objetivosunclassified

“…A expansão da geração distribuída de energia elétrica utilizando geradores JUNG et al, 2002), (KEREKES; TEODORESCU; BORUP, 2007), (GUBÍA et al, 2007), (GONZALEZ et al, 2007), (GONZALEZ et al, 2008), (ARAUJO; ZACHARIAS; MALLWITZ, 2010), (XIAO; XIE, 2010), (KEREKES et al, 2011), (XIAO et al, 2011, (YANG et al, 2012), (ZHANG et al, 2013), (KOUTROULIS; BLAABJERG, 2013), (GERARDO; RAYMUNDO; MIGUEL, 2015), (LI et al, 2015), (SHAYESTEGAN et al, 2018), (KHAN et al, 2020), (XIAO, 2021), (XIAO;WANG, 2021).…”

Section: Fotovoltaicos Conectados à Rede Elétricamentioning

confidence: 99%

Metodologia de projeto integrada para filtro LCL (modo comum e diferencial) e controlador de corrente aplicada à inversores fotovoltaicos monofásicos sem transformador conectados à rede elétrica.

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Transformerless Photovoltaic Grid-Connected Inverters

Cited by 6 publications

References 0 publications

Control scheme based on capacitor voltage second-order complex-vector feedforward for LCL-filtered inverter

Control scheme based on capacitor voltage second-order complex-vector feedforward for LCL-filtered inverter

Topology Optimization Analysis of Leakage Current Suppression in Three-Level Four-Leg Photovoltaic Grid-Connected Inverter

Metodologia de projeto integrada para filtro LCL (modo comum e diferencial) e controlador de corrente aplicada à inversores fotovoltaicos monofásicos sem transformador conectados à rede elétrica.

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