TY - GEN
T1 - Analysis of input filter interactions in cascade buck converters
AU - Iftikhar, M. Usman
AU - Bilal, A.
AU - Sadarnac, D.
AU - Lefranc, P.
AU - Karimi, C.
PY - 2008
Y1 - 2008
N2 - Many applications of switch-mode dc-dc converters require high conversion ratios (Vout/Vin), thus encouraging the use of n-stages connected in cascade. However, when an input filter is added to an existing cascade converter "black box", it can cause system instability and performance degradation due to the negative dynamic input resistance characteristic of the converter. In this paper, we investigate this interaction of input filters in cascaded buck converters. The problem is treated by using a small-signal averaged model of the converter in which natural parasitic resistances of the circuit elements are also taken into account. Based on the open-loop transfer function of the system, a design criterion is proposed for the dimensioning of input filter damping that ensures closed-loop stability of the filter-converter system without over sizing or under sizing the filter. Theoretical results of this paper are validated experimentally.
AB - Many applications of switch-mode dc-dc converters require high conversion ratios (Vout/Vin), thus encouraging the use of n-stages connected in cascade. However, when an input filter is added to an existing cascade converter "black box", it can cause system instability and performance degradation due to the negative dynamic input resistance characteristic of the converter. In this paper, we investigate this interaction of input filters in cascaded buck converters. The problem is treated by using a small-signal averaged model of the converter in which natural parasitic resistances of the circuit elements are also taken into account. Based on the open-loop transfer function of the system, a design criterion is proposed for the dimensioning of input filter damping that ensures closed-loop stability of the filter-converter system without over sizing or under sizing the filter. Theoretical results of this paper are validated experimentally.
KW - cascade dc-dc converter
KW - control loop stability
KW - Input filter interaction
KW - small-signal averaged model.
UR - https://www.scopus.com/pages/publications/54549086800
U2 - 10.1109/ICIT.2008.4608690
DO - 10.1109/ICIT.2008.4608690
M3 - Conference contribution
AN - SCOPUS:54549086800
SN - 9781424417063
T3 - Proceedings of the IEEE International Conference on Industrial Technology
BT - 2008 IEEE International Conference on Industrial Technology, IEEE ICIT 2008 - Conference Proceedings
T2 - 2008 IEEE International Conference on Industrial Technology, IEEE ICIT 2008
Y2 - 21 April 2008 through 24 April 2008
ER -