A Real Time Predictive Maintenance System of Aluminium Electrolytic Capacitors Used in Uninterrupted Power Supplies

Abstract

Abstract-This paper presents a low cost method to realize a real time condition monitoring and a predictive maintenance system of an electrolytic capacitor used in Uninterrupted Power Supplies (UPS). This method consists in detecting the changes on real time in equivalent series resistance (ESR) and the capacitance C values of the electrolytic capacitors. Simulation and experimental results are presented to illustrate the proposed monitoring technique. The proposed method can be used in UPS where waveforms are continuously varying in amplitude, frequency and versus temperature. The proposed on line failure prediction method has the merits of using only the existent resources in UPS and with the use of knower algorithms.

Online monitoring of power extraction efficiency for minimizing payback period of solar PV system

“…The value of capacitance falls linearly with time [10], as given below, 0 C = C + A .t (6) where, C 0 = initial value of capacitance (mF) A = parameter depends on type of capacitor It is specified in the datasheet [14] that if ESR becomes twice of initial ESR, the capacitance value falls to 80% of initial value. For a given operating temperature, ESR and capacitance value can be calculated at any instant of time by using (5) and (6).…”

“…Several approaches for online health monitoring of electrolytic capacitor is proposed in literatures [5]- [10]. In [9], online monitoring technique for ripple voltage across capacitor is suggested.…”

Degradation model and maintenance strategy of the electrolytic capacitors for electronics applications

“…An equivalent circuit model for a typical electrolytic capacitor is shown in Fig.l, in which CAK is the ideal capacitance between anode and cathode, Rp is the parallel resistance which represents all the losses in the dielectric and the leakage between the two electrodes, R/ is the connection and electrodes equivalent series resistance and L is connection and winding equivalent series inductance [3]. ESR and ESL represent capacitance, all the components losses and equivalent serial inductance due to the wound structure respectively.…”

“…Unfortunately, it is reported that the electrolytic capacitors are the weakest components in power electronic circuits. According to the statistics data of failure cases, the electrolytic capacitors are responsible for the failure of power electronics system in more than 50% cases [1 ]- [3]. Therefore, the research of its failure and degradation characteristic to avoid the unanticipated fault has a great practical value.…”

“…In fact, prediction model and maintenance decision-making are equally important for improvement of power electronic system reliability. Based on the method proposed by [3], the ESR and capacitance are monitored, and then the prediction model and maintenance strategy are researched in this paper.…”