Comparison of PV systems with maximum DC voltage 1000V and 1500V

The purpose of this work is the comparison of two different photovoltaic (PV) arrays with different maximum permissible voltage from a technical point of view. In addition, inverter input specifications are taken into account since they affect the PV array design. The comparative cases include PV arrays with inverters of 1000 and 1500 V maximum input voltage. The most commonly used are those with 1000V maximum voltage, but it is claimed that by using those with 1500 V maximum voltage there is potential for more cost effective PV systems. One of the PV array design parameters that are affected by the inverter´s maximum voltage rating is the number of PV modules that can be connected in series. In this study it is shown how the ratio of number of PV modules per string (Nms ratio) between the two comparative cases is related to the reduction of the PV array cabling and number of combiner boxes (CB). In addition the comparison was iterated for various Nms ratios and for three inverter power ratings of 800kW, 1.5MW and 3MW. Finally, the savings in conductor mass and number of CB of the PV array with respect to the Nms ratio of the two comparative studies are presented.