Revista Eletrônica de Potência (Brazilian Journal of Power Electronics)

Palavras Chaves: Equalização de Tensão, Sistema de Armazenamento de Energia, Supercapacitores

Resumo

A utilização de supercapacitores como elemento de acumulação de energia tem se tornado muito popular nos últimos anos. Todavia, na maioria das aplicações é necessária a associação de vários desses elementos em série, devido às baixas tensões nominais. Nessas condições de operação, as tensões em cada elemento do banco de supercapacitores podem apresentar desequilíbrio devido a variações paramétricas. Este artigo apresenta uma topologia de circuito de equalização da tensão dos supercapacitores integrado ao conversor Buck utilizado para carga do banco. O circuito proposto realiza a equalização da tensão do banco de forma não dissipativa e sem a necessidade de circuitos adicionais de controle. Um protótipo é implementado e os resultados experimentais obtidos mostraram que desequilíbrios de tensão de até 86% foram reduzidos para apenas 5,2% durante o processo de carga do banco, sem, no entanto, exceder o máximo valor nominal de tensão de cada supercapacitor.

Title: Buck-flyback converter for charging and voltage equalizer on supercapacitor bank

Keywords: Energy Storage Systems, supercapacitor, Voltage Equalizer

Abstract

The application of supercapacitors as energy storing devices became very popular in the last years. However, typically the supercapacitors are connected in series because its low nominal voltages. In this operating conditions, the voltages in each supercapacitor may be unbalanced due their parametric variations. This paper presents a new voltage equalization circuit. The proposed circuit is integrated with the Buck converter used to charge the supercapacitor bank. This is a non-dissipative circuit and do not requires any specific control circuit. A prototype is implemented and experimental results show that unbalances up to 86% in the supercapacitors voltages, were reduced to only 5.2% during the bank's charge process. Nevertheless, each supercapacitor maximum voltage remained within its nominal value.

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