Optimization of a DC Capacitor Tank

The choice of a set of capacitors for a dc link may be very different depending on the system requirements and user constraints. This paper shows how to achieve the best choice of a hybrid association of electrolytic capacitor and higher frequency technology (polyester for instance). Maximum allowed rms current in the electrolytic capacitor is obviously taken into account. The input filter of a buck converter is chosen as example. Various constraints are considered: voltage ripple, differential-mode electromagnetic-interference level, losses, weight, volume, surface, etc. Objective function for optimization is defined by the user and may be any of the previous parameters. The optimized result consists in the number and the values of components for both capacitor technologies.