Reliability-oriented optimization of aluminum electrolytic capacitor considering uncertain mission profile

Aluminum electrolytic capacitors (Al-Caps) are responsible for the failure of power converters on a considerable scale. To optimize the lifetime of Al-Caps under various operation conditions, this paper proposes a reliability-oriented optimization method for aluminum electrolytic capacitors (Al-Caps), which considers uncertainties of mission profiles. The Al-Cap in LED driver is taken as a case study to illustrate the optimization procedure. The uncertainties of mission profile (i.e. ambient temperature and operating time) are modelled by kernel density estimation according to historical weather data. Then, the temperature stresses of Al-Cap under various operating conditions are analyzed by both thermal simulation and experiments. Taking uncertainties of mission profile into account, Monte Carlo simulation is carried out to calculate the B₁₀ lifetime distribution of Al-Caps. Afterwards, the reliability-oriented optimization formulation is established by integrating both the average value and standard deviation of mission profile-based lifetime distributions. Finally, the particle swarm algorithm is applied to obtain an optimal solution of Al-Cap design. The proposed method could offer a robust reliability design of Al-Cap in LED driver, which improves both reliability and robustness at the same time.