Design and Simulation of a PV System under Different Operating Conditions

Over the past few years, the installed power of wind and photovoltaic power plants in Bulgaria has been significantly increased. The aim of this article is to proposes a methodology for the design and construction of a stationary 75kWp photovoltaic power plant, connected to the public grid at the MV level through a CSS (0.4/21 kV). The proposed design methodology is convenient and easy to implement, and the results of practical construction show that the difference between the estimated and the obtained electricity production is less than 5%. It has been found that two main factors have the strongest impact on the electricity production - the pollution of the surface of the modules (i.e. field dust, bird droppings etc.) and the ambient temperature. Reducing their impact can be achieved by using a cleaning and cooling system with temperature feedback, which would lower the operating temperature of the modules from 80-85°C to 47°C /NOCT/. The results of the simulation studies performed show that this would increase electricity production by about 20%, which would compensate for the degradation of the photovoltaic modules.