An Overview of Condition Monitoring Techniques for Capacitors in DC-Link Applications

Abstract

Capacitors are widely used in dc links of power electronic converters to balance power, suppress voltage ripple, and store short-term energy. Condition monitoring (CM) of dc-link capacitors has great significance in enhancing the reliability of power converter systems. Over the past few years, many efforts have been made to realize CM of dc-link capacitors. This paper gives an overview and a comprehensive comparative evaluation of them with emphasis on the application objectives, implementation methods, and monitoring accuracy when being used. First, the design procedure for the condition monitoring of capacitors is introduced. Second, the main capacitor parameters estimation principles are summarized. According to these principles, various possible CM methods are derived in a step-by-step manner. On this basis, a comprehensive review and comparison of CM schemes for different types of dc-link applications are provided. Finally, application recommendations and future research trends are presented.

Power Electronics Reliability: State of the Art and Outlook

“…For example, on-state saturation voltage and thermal resistance between junction-to-case are widely used health precursors for IGBT modules, and they are applied for both accelerated degradation testing [53] and condition monitoring [6]. Capacitance, Equivalent Series Resistance (ESR), dissipation factor, and insulation resistance are usually used for capacitors [12,13]. Fig.…”

“…Degradation modeling is essential to predictive maintenance. The following two key challenges remain to be addressed: 1) Most condition monitoring methods are limited to a single type of component or an individual component [6,7,13], [105]. Nevertheless, at the application level, degradation could occur on multiple components concurrently.…”

“…Research activities and outcomes worldwide have increased significantly in the last decade. Many of the results are reviewed in [4][5][6][7][8][9][10][11][12][13]. In [4], the primary research activities in the power cycling tests of power modules between 1994 and 2015 are summarized, which shows the varieties in packaging technologies, control strategies, failure mechanisms Huai Wang and Frede Blaabjerg are with the Department of Energy Technology, Aalborg University, 9220 Aalborg, Denmark.…”

“…The failure mechanisms of GaN devices are discussed in [11]. In addition to active components, capacitor reliability and condition monitoring methods are discussed in [12,13], respectively. These overview papers provide a foundation to understand the state-of-the-art research on power electronics reliability.…”

“…Most of the references that will be discussed in this paper are drawn from the last five years. For a more comprehensive list of references and discussions, please refer to [1][2][3][4][5][6][7][8][9][10][11][12][13]. It should be noted that this paper has the following limited scopes:…”