Analysis of external dynamic loads influence to photovoltaic module structural performance

Abstract

Efficiency of modern photovoltaic (PV) systems decreases significantly when the crystalline structure of PV modules is damaged due to climatic factors, such as wind and mechanically similar dynamic effects. General certifications of PV modules consist of only static tests (according to Photovoltaic standard IEC 61215 and IEC 61646), however in reality, PV modules are operating in a dynamic environment. The purpose of the article is to show that for the certification of PV modules the dynamic characteristics of PV modules must be accounted also. Nowadays PV modules are used in different dynamic objects like cars, boats etc., where dominant loads are of dynamic environment. This paper presents theoretic and experimental studies. For the investigation of dynamic loads acting on PV modules, a testing stand has been designed. PV modules were loaded with cyclic dynamic loads. During the experiment, the PV modules were loaded with external excitation, the excitation amplitude is not exceeding more than 7 mm. During the experiment, the PV modules were excited, in the frequency range of 0 to 40 Hz and the sweep generating mode was used. The aim of this excitation to simulate different weather conditions. Experimental and theoretical results showed the reaction of PV modules in different weather conditions (which means that the effect of different wind speeds is evaluated). The proposed assessment methodology can be applied successfully when designing PV modules and accounting for mechanical dynamic effects. In conclusion, it is not accurate and appropriate to evaluate the safety and stability of PV modules just through the existing static analysis in IEC 61215. The dynamic effects of the loading on PV module also need to be paid attention to. The attention needs to be paid to the dynamic effects of the loading on PV module.