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Deterioration analysis of
aluminum electrolytic capacitor for DC-DC converter
Lifeng Wu*, Yong Guan, Yinyu
Du, Shihong Zhou and Wei Pan
Beijing Engineering Research Center of High Reliable
Embedded System, Capital Normal University, Beijing 100048,
People’s Republic of China.
*Corresponding author. E-mail:
wooleef@gmail.com.
Accepted 25 January, 2011 |
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Aluminum electrolytic capacitor is one of the key components
that restrict the life of DC-DC converter. Studying its
deterioration analysis has advanced to realizing the
prognostics and health management (PHM) technology of DC-DC
converter. The main deterioration modes of aluminum
electrolytic capacitor include the capacitance decrease and
the equivalent series resistance (ESR) increases. These
cause the ripple voltage to increase and eventually lead to
the DC-DC converter failure. Some parameters of DC-DC
converter (such as the ripple voltage, the ripple current,
etc.) are selected as the feature signals of the aluminum
electrolytic capacitor deterioration. By monitoring the
changes of the feature signals, the aluminum electrolytic
capacitor deterioration degree can be measured indirectly.
Through theoretical analysis, this paper proposed a new idea
to predict the remaining useful life (RUL) of DC-DC
converter, that is, establishing the curve of the ripple
voltage as the aluminum electrolytic capacitor deterioration
and setting a warning point in the curve. When the change
rate of the ripple voltage reached the warning point, the
life of the DC-DC converter will come to an end. So, the RUL
of the DC-DC converter can be predicted. In this paper, the
buck converter is verified by simulation and physical
experiments amid good agreements with the theory.
Key words: Aluminum electrolytic capacitor, DC-DC converter,
deterioration, capacitance, equivalent series resistance
(ESR), ripple voltage, remaining useful life (RUL),
prognostics and health management (PHM). |
