Analysis and evaluation of charge balancing circuits on performance, reliability and lifetime of supercapacitor systems

Supercapacitors, also known as ultracapacitors or electric double layer capacitors (ELDC), are electrical energy storage devices, which offer high power density, extremely high cycling capability and mechanical robustness. Due to their electrical performance, supercapacitors have a high potential to be used in industrial applications. To improve the performance, reliability and lifetime of these capacitors, charge balancing circuits are employed. In this paper, different equalization concepts are analyzed and evaluated. In addition, a simulation approach for the design of supercapacitor systems is proposed. As an example, results from an automotive application are presented.