DC Cabling of Large-Scale Photovoltaic Power Plants

Abstract

The development of Floating Solar Photovoltaic (FPV) systems is a sign of a promising future in the Renewable Energy field. Numerous solar modules and inverters are mounted on large-scale floating platforms. It is important to design the system so that the inverter operates in its optimum range most of the time. In order to achieve this goal on the DC side, serial and parallel connections of solar modules are used. As a result, the cabling of the PV array architecture is an important issue. Modern electrical installation design requires reducing costs in cabling materials, equipment installation, and maintenance. The reduction of losses and the amount of time required to complete the design are also significant. Therefore, the main topic of this paper is DC cabling in large-scale FPV power plants (>1 MV). The serial-parallel (SP) connection scheme of solar modules and the percentage of power loss in DC cables are considered. Furthermore, a general method for determining cable lengths for FPV power plants is defined. The temperature influence on losses in DC cables is analyzed. A new method for determining the current at the maximum power point (MPP) as a function of temperature is proposed. A case study is conducted using a hypothetical 3 MW FPV power plant, and the obtained results are presented and analyzed.