Revista Eletrônica de Potência (Brazilian Journal of Power Electronics)

Palavras Chaves: capacitor ativo, celula de desalojamento de potencia, ondulação de potencia

Resumo
Este artigo apresenta uma célula ativa de desacoplamento de potência aplicada à mitigação da ondulação de tensão de um microinversor fotovoltaico de dois estágios. Essa célula é projetada para ser acoplada ao barramento CC principal do microinversor e desviar a ondulação de 120 Hz para um barramento secundário, configurando uma alternativa viável ao uso de capacitores eletrolíticos, usualmente empregados com esse propósito. O artigo traz uma revisão bibliográfica que aponta para as principais topologias e estratégias de controle normalmente utilizadas em células de desacoplamento de potência, detalha o equacionamento voltado ao seu dimensionamento e apresenta resultados experimentais considerando duas estratégias de controle distintas. Tais resultados comprovam a habilidade da célula de desacoplamento em mitigar a componente de 120 Hz da tensão do barramento CC, reduzindo-a de 7,2% para apenas 1,1%.

Title: POWER DECOUPLING CELL FOR PHOTOVOLTAIC MICROINVERTERS

Keywords: active capacitor, dc bus voltage, power decoupling cell, power ripple

Abstract
This paper presents an active power decoupling cell applied to mitigate the voltage ripple in a two-stage photovoltaic microinverter. This cell is designed to be coupled to the main DC bus of the microinverter and to divert the 120 Hz ripple to a secondary bus, providing a useful alternative to the use of electrolytic capacitors, currently applied for this purpose. The paper brings a literature review that points to the main topologies and control strategies normally used in power decoupling cells, details the sizing equations and presents experimental results considering two different control configurations. These results prove the ability of the decoupling cell in mitigating the 120 Hz component of the DC bus voltage, which is reduced form 7.2% to 1.1%.

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