DC-link MPPF Capacitors Online Condition Monitoring System for AC/DC power converters integrated in Converter Control System

In the realm of power electronic converters, the reliability and lifespan of DC-link capacitors play a crucial role in determining the overall system performance. This study contributes to the advancement of knowledge in the field of lifetime management and estimation for DC-link capacitors. It introduces an online estimation algorithm implemented in a 120kW PV inverter demonstrator, utilizing TDK Electronics' ultra-low inductance series B2563* capacitors. The paper demonstrates the implementation of the monitoring algorithm without the need of additional or dedicated voltage and/or current sensors during converter operation. All calculations are based on existing variables or estimates of capacitor variables. The impact of factors such as ambient temperature, managed power, and DC-Link voltage is analysed and tested in the prototype. Key words. DC-link capacitor degradation, Predictive maintenance, Smart inverters.