Study on Effect of Installation Location on Lifetime of PV Inverter and DC-to-AC Ratio

The reliability improvement of a PV inverter is one of the important aspects to decrease the cost of PV energy. Furthermore, oversizing the PV arrays is a commonly applied strategy to achieve the cost of PV energy reduction but it may also have a negative impact on the cost of PV energy since it accelerates the wear-out of the PV inverter. Therefore, the lifetime of the PV inverter has to be considered to find a safe limit for the oversizing of the PV arrays but there is a lack of study on this effect. This paper studies the effect of the installation location on the lifetime of the PV inverter together with DC/AC ratio. The lifetime evaluation of NPC inverter is carried out with three installation locations inclusive of the effect of the cooling capacity. Furthermore, the impact of DC/AC ratio on the lifetime of the PV inverter is investigated by taking into account the influence of the installation location to show the importance of the lifetime of the PV inverter to select the optimum DC/AC ratio to minimize the cost of PV energy.