Single‐phase transformerless bi‐directional inverter with high efficiency and low leakage current

Lee, Sungho; Kim, Kyu-Tae; Kwon, Jung-Min; Kwon, Bong-Hwan

doi:10.1049/iet-pel.2013.0074

Cited by 37 publications

(18 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, the conversion efficiency of bipolar SPWM inverter is lower because of the high switching losses and magnetic inductor losses. Therefore to solve the problem of leakage current and low efficiency, many DC-AC inverter topologies based on full-bridge inverter have been proposed [6,8,[15][16][17][18][19][20][21][22][23][24][25]. Gonzalez et al [8] proposed full-bridge with DC bypass topology, in which two switches and two diodes are added with a full-bridge inverter.…”

Section: Introductionmentioning

confidence: 99%

H6‐type transformerless single‐phase inverter for grid‐tied photovoltaic system

Islam

Mekhilef

2015

IET Power Electronics

123

View full text Add to dashboard Cite

There has been an increasing interest in transformerless inverter for grid-tied photovoltaic (PV) system because of the benefits of lower cost, smaller volume as well as higher efficiency compared with the ones with transformer. However, one of the technical challenges of the transformerless inverter is the safety issue of leakage current which needs to be addressed carefully. In addition, according to the international regulations, transformerless inverter should be capable of handling a certain amount of reactive power. In this study, a new H6-type transformerless inverter for grid-tied PV system is proposed that can eliminate the threat of leakage current. The proposed topology has also the capability to inject reactive power into the utility grid. Three-level output voltage employing unipolar sinusoidal pulsewidth modulation can be achieved with the proposed topology. The proposed topology structure and detail operation principle with reactive power control are investigated. The relationship among the existing topologies and their reactive power control capability are also discussed. The proposed topology is simulated in MATLAB/Simulink software to initially verify the accuracy of theoretical explanations. Finally, a universal prototype rated 1 kW has been built and tested. The experimental results validate the theoretical analysis and simulation results.

show abstract

Section: Introductionmentioning

confidence: 99%

H6‐type transformerless single‐phase inverter for grid‐tied photovoltaic system

Islam

Mekhilef

2015

IET Power Electronics

123

View full text Add to dashboard Cite

show abstract

“…Semi-Z-source inverter winding losses includes the conduction losses of DC resistance R DC and AC resistance R AC . Core losses of the inductor can be calculated from the data sheet [47] at applied switching frequency by calculating the peak-to-peak flux density by the following equation DB = Vt NA e (27) where ΔB, V, t, N and A e are flux density in Tesla, applied voltage to the winding in volts, time of applying voltage in seconds and cross-section area of core in square metre. The conducting losses for DC and AC resistance of the inductors L 1 and L 2 can be calculated by using (28)- (31), respectively…”

Section: Inductor Power Losses Of Semi-z-source Invertermentioning

confidence: 99%

“…To improve the performance and lessen the cost, many transformerless inverter topologies based on traditional inverter and Z-source or quasi-Z-source inverters have been presented and analysed for renewable energy distributed generators especially for PV application in [14,[24][25][26][27][28][29][30][31][32][33][34][35]. Doubly grounded features are not included in most of these topologies.…”

Section: Introductionmentioning

confidence: 99%

Semi‐Z‐source inverter topology for grid‐connected photovoltaic system

Ahmed

Mekhilef

2015

IET Power Electronics

View full text Add to dashboard Cite

Transformer-less inverters are necessary parts for grid-connected renewable energy resources. Owing to its cost effectiveness, downsize and less weight, great attention has been paid to these inverters development. With these aforementioned advantages, these inverters have limitations like the flow of leakage current through photovoltaic arrays, high total harmonic distortion (THD) at inverter's output and DC current injection to the grid. This study presents coupled inductor-based single-phase transformer-less semi-Z-source inverter topology to lessen those limitations. Since the DC input and AC output voltage share a common ground, the presented inverter system is categorised under doubly grounded topologies. For the purpose of handling, the non-linearity of the voltage gain of semi-Z-source inverter, a non-linear sinusoidal pulse-width modulation technique has been employed. The prototype of the suggested inverter has been constructed. The performance and compatibility of modulation technique are verified under different loading conditions. The feasibility of the configuration is ensured based on the mitigated common-mode leakage current, the substantially lower THD as well as DC current injected to the grid. Moreover, the presence of coupled inductor significantly contributes in reducing input current ripple, installation area of the inverter and enhancing the efficiency. Finally, this topology exhibits appreciable performance to operate synchronously and transfer power to the grid.

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

Revista 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

Single‐phase transformerless bi‐directional inverter with high efficiency and low leakage current

Cited by 37 publications

References 18 publications

H6‐type transformerless single‐phase inverter for grid‐tied photovoltaic system

H6‐type transformerless single‐phase inverter for grid‐tied photovoltaic system

Semi‐Z‐source inverter topology for grid‐connected photovoltaic system

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

Contact Info

Product

Resources

About