CALCE Prognostics Approach for Multilayer Ceramic Capacitors
Capacitors exhibit a variety of behaviors during degradation, including parametric drift, intermittent, and self-healing. Traditional methods of monitoring and data analysis are not good at identifying signs which signal imminent failure. In applications such as power supplies, waiting until a capacitor has completely failed, especially in short circuit mode, can be disastrous. Circuit performance is dependent on several electrical characteristics; chiefly including capacitance, dissipation factor, and insulation resistance. Thus, a method is desired which can simultaneously monitor multiple electrical parameters for indications of impending failure. CALCE is working towards developing a prognostics approach using PHM techniques and precursors to failure in multilayer ceramic capacitors in actual operating conditions. Approaches considered are Mahalanobis Distance method and Multivariate State Estimation Techniques.