Optimal Space Vector Modulation for Enhancing Reliability of the DC-Link Capacitor in a 2 -Level Converter

In power conversion applications, the DC-link capacitor is a critical component prone to degradation and its reliability affects the whole converter lifespan. Two-levels converters are commonly operated using pulse patterns designed according to conventional modulation schemes to generate a desired AC voltage. The effect of the switching on the DC-link capacitor current is not considered in the planned pulse pattern. This work proposes an alternative modulation strategy where the patterns are optimized to minimize the RMS current and thus reduce the degradation effect of current ripples on the capacitor. A comparative performance analysis of the reliability-based modulation scheme with respect to the standard practice is carried out based on simulation. The analysis results demonstrate that the proposed method generates the desired voltage output with low levels of harmonic distortion, while significantly decreasing RMS current values and thus enhancing capacitor lifetime.