Analysis of Energy Factor and mathematical modeling for power DC/DC converters

Fang Lin Luo

Mathematical modelling of power DC/DC converters is a historical problem accompanying development of the DC/DC conversion technology since 1940's. The traditional mathematical modelling is successful to describe fundamental converters but not available for complex structure converters due to a dramatic increase of the order of corresponding differential equations. We have to search an other way to establish mathematical modelling for power DC/DC converters.

Energy storage in power DC/DC converters has been paid attention to since long time ago. Unfortunately, there is no clear concept to describe the phenomena and reveal the relationship between the stored energy and the characteristics of power DC/DC converters. In this paper, we have theoretically defined a new concept - Energy Factor (EF) and investigated the relations between EF and the mathematical modelling of power DC/DC converters. EF is a new concept in power electronics and conversion technology, which thoroughly differs from the traditional concepts such as power factor (PF), power transfer efficiency (h), total harmonic distortion (THD), and ripple factor (RF). EF and the subsequential other parameters can illustrate the system stability, reference response, and interference recovery. This investigation is very helpful for system design, and DC/DC converters characteristics.

Keywords: mathematical modeling, energy factor (EF), power factor (PF), power transfer efficiency (h), total harmonic distortion (THD), ripple factor (RF), power DC/DC converters, system stability, step response and impulse response.