Battery–ultracapacitor hybrids for pulsed current loads: A review

Battery versus hybrid power sources performance is examined in the manuscript. Passive, semi-active and fully active battery–ultracapacitor hybrids show obvious superiority over battery only powered pulsed current loads. Passive hybrid is the most simple and cheap arrangement, however its uncontrolled nature results in several drawbacks during the operation. On the other hand, the fully active hybrids achieve superior performance at the expense of two DC–DC converters and the corresponding control circuitry. The trade off between the topologies is the semi-active hybrid, employing only one DC–DC converter and attaining a compromising performance. The thorough characterization of each topology and sub-topology is presented in the manuscript and design methodology is derived for a particular case of pulsed current load.