Estimation of the lifetime consumption of power semiconductors due to power cycling in a photovoltaic inverter

This paper deals with the estimation of the lifetime consumption of power semiconductor modules due to power cycling with regard to a 125 kW photovoltaic inverter. The described calculation model takes into account a demanding photovoltaic mission profile, the operating point dependent behavior of the photovoltaic inverter, the amount of parallel semiconductor chips and the cooling system design. Different packaging technologies including state-of-the-art and new technologies with improved power cycling capability are considered based on power cycling diagrams published by semiconductor module manufacturers and the possible influence of the usage of silicon carbide instead of silicon chips is discussed. As a result, the calculated lifetime consumption as a function of the maximum junction temperature of the inverter design is presented.