Optimised full‐bridge transformerless photovoltaic grid‐connected inverter with low conduction loss and low leakage current

Xiao, Huafeng; Liu, Xipu; Lan, Ke

doi:10.1049/iet-pel.2013.0404

Cited by 41 publications

(32 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…3(b). The inductor voltage is neglected, and the inverter output voltage is considered equal to the grid voltage [9]- [19].…”

Section: A Zero-crossing Distortionmentioning

confidence: 99%

“…To suppress the leakage current, new freewheeling paths are constructed to separate the PV array from the grid [2], [9]- [19]. According to the position of freewheeling switches, the topologies can be divided into the DC bypass ones [9]- [12] and the AC bypass ones [2], [13]- [19].…”

Section: Introductionmentioning

confidence: 99%

“…According to the position of freewheeling switches, the topologies can be divided into the DC bypass ones [9]- [12] and the AC bypass ones [2], [13]- [19]. In H5 topology, an active switch is introduced to the DC bus to decouple the PV module [10].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Optimized Hybrid Modulation Strategy for AC Bypass Transformerless Single-Phase Photovoltaic Inverters

Deng¹,

Sun²,

Yang³

et al. 2016

Journal of Power Electronics

View full text Add to dashboard Cite

The full-bridge inverter, widely used for single-phase photovoltaic grid-connected applications, presents a leakage current issue. Therefore, an AC bypass branch is introduced to overcome this challenge. Nevertheless, existing modulation strategies entail drawbacks that should be addressed. One is the zero-crossing distortion (ZCD) of the AC current caused by neglecting the AC filter inductor voltage. Another is that the system cannot deliver reactive power because the AC bypass branch switches at the power frequency. To address these problems, this work proposes an optimized hybrid modulation strategy. To reduce ZCD, the phase angle of the inverter output voltage reference is shifted, thereby compensating for the neglected leading angle. To generate the reactive power, the interval of the negative power output is calculated using the power factor. In addition, the freewheeling switch is kept on when power is flowing into the grid and commutates at a high frequency when power is fed back to the DC side. In this manner, the dead-time insertion in the high-frequency switching area is minimized. Finally, the performances of the proposed modulation strategy and traditional strategies are compared on a universal prototype inverter. Experimental results validate the theoretical analysis.

show abstract

“…3(b). The inductor voltage is neglected, and the inverter output voltage is considered equal to the grid voltage [9]- [19].…”

Section: A Zero-crossing Distortionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Optimized Hybrid Modulation Strategy for AC Bypass Transformerless Single-Phase Photovoltaic Inverters

Deng¹,

Sun²,

Yang³

et al. 2016

Journal of Power Electronics

View full text Add to dashboard Cite

show abstract

“…De modo geral, o objetivo final das pesquisas é o mesmo: extrair a máxima potência possível dos painéis. Porém, este o objetivo pode ser alcançado de diversas maneiras diferentes, como focar no rendimento dos conversores usando topologias com baixas perdas [3], utilizar componentes de melhor qualidade, incluindo os materiais magnéticos e semicondutores [4], aprimorar técnicas de comutação e modulação [5], [6], atuar na redução da corrente de dispersão ocasionada pela tensão de modo comum dos conversores [7], [8].…”

Section: Introductionunclassified

Inversores Comutados pela Rede Associados a um Autotransformador Multipulsos para a Geração Fotovoltaica

Brighenti¹,

Batschauer²,

Mezaroba³

2016

Eletrônica de Potência

View full text Add to dashboard Cite

Resumo -Conversores não isolados aplicados a sistemas fotovoltaicos normalmente possuem algumas vantagens em relação aos conversores isolados como redução de custos e melhor eficiência devido, principalmente, à ausência de um transformador. Neste contexto, uma alternativa para o processamento da energia obtida pelos painéis fotovoltaicos é o uso de um autotransformador multipulsos associado a retificadores controlados com ângulo de disparo entre 90°-180° (inversores comutados pela rede). Esta solução possui algumas vantagens como robustez, baixa manutenção, alta confiabilidade e baixo custo, além de ser muito adequada para geração fotovoltaica em locais remotos onde estas vantagens são mais importantes que a redução de volume. Outra importante característica é que a associação dos enrolamentos do autotransformador gera sistemas trifásicos defasados entre si, reduzindo a quantidade do conteúdo harmônico das correntes injetadas na rede. Este artigo apresenta um conversor de 18 pulsos usando um autotransformador com conexão Y-diferencial fechada. A potência processada pelo autotransformador é apenas 21,9% da potência total fornecida ao sistema, aumentando a eficiência e reduzindo o custo total. Palavras-Chave LINE-COMMUTATED INVERTERS ASSOCIATED TO A MULTI-PULSE AUTOTRANSFORMER FOR PHOTOVOLTAIC GENERATIONAbstract - Non-isolated converters applied in photovoltaic (PV) systems usually have some advantages over the isolated converters, like reduced cost and better efficiency mainly due to the absence of a transformer. In this context, one alternative for the processing of energy acquired by PV modules is the use of non-isolated multipulse autotransformers associated to controlled rectifiers with a firing angle between 90°-180° (line-commutated inverters). This solution has some advantages like robustness, low maintenance, high reliability and low cost and it is very suitable to PV generation in remote areas when these advantages are more important than the size reduction. Another important feature is that the association of the autotransformer's windings generates three-phase systems displaced each other, reducing the amount of the harmonic content in the currents injected into the grid. This paper will present an 18-pulse converter using an autotransformer with Y-differential connection. The power processed by autotransformer is only 21.9% of the total power provided to the system, increasing the efficiency and reducing the overall cost. Em sistemas fotovoltaicos é muito importante fazer o rastreamento da máxima potência, pois parâmetros como temperatura do painel e irradiação solar variam durante o dia, mudando os valores de tensão e corrente em que os painéis fotovoltaicos fornecem a potência máxima ao sistema. Neste contexto, estão as técnicas para efetuar este rastreamento de forma eficiente. Comparações entre as principais técnicas são apresentadas em [9] e [10]. KeywordsO principal objetivo deste trabalho é propor um sistema de geração fotovoltaica usando tecnologias robustas e consolidadas para obter uma boa...

show abstract

“…In [16], a novel H6 topology is proposed, which constructs a new direct power passing path in a half cycle to reduce the conduction loss. The highly efficient reliable inverter concept (HERIC) topology applies a bidirectional switch to realize the disconnection of the converter and the grid during zero-voltage vectors [17]. Due to the reduction of switches, the ac-decoupling method can provide lower power losses in the conduction path.…”

Section: Introductionmentioning

confidence: 99%

A Modified Single-Phase Transformerless Z-Source Photovoltaic Grid-Connected Inverter

Liu¹,

Li²,

Yan³

et al. 2015

Journal of Power Electronics

View full text Add to dashboard Cite

In a grid-connected photovoltaic (PV) system, the traditional Z-source inverter uses a low frequency transformer to ensure galvanic isolation between the grid and the PV system. In order to combine the advantages of both Z-source inverters and transformerless PV inverters, this paper presents a modified single-phase transformerless Z-source PV grid-connected inverter and a corresponding PWM strategy to eliminate the ground leakage current. By utilizing two reversed-biased diodes, the path for the leakage current is blocked during the shoot-through state. Meanwhile, by turning off an additional switch, the PV array is decoupled from the grid during the freewheeling state. In this paper, the operation principle, PWM strategy and common-mode (CM) characteristic of the modified transformerless Z-source inverter are illustrated. Furthermore, the influence of the junction capacitances of the power switches is analyzed in detail. The total losses of the main electrical components are evaluated and compared. Finally, a theoretical analysis is presented and corroborated by experimental results from a 1-kW laboratory prototype.

show abstract

Optimised full‐bridge transformerless photovoltaic grid‐connected inverter with low conduction loss and low leakage current

Cited by 41 publications

References 19 publications

Optimized Hybrid Modulation Strategy for AC Bypass Transformerless Single-Phase Photovoltaic Inverters

Optimized Hybrid Modulation Strategy for AC Bypass Transformerless Single-Phase Photovoltaic Inverters

Inversores Comutados pela Rede Associados a um Autotransformador Multipulsos para a Geração Fotovoltaica

A Modified Single-Phase Transformerless Z-Source Photovoltaic Grid-Connected Inverter

Contact Info

Product

Resources

About