Electrical fault and reliability analysis of various PV array connection types

Abstract

The increasing interest in solar energy has led to the development of various connection types designed to enhance the efficiency of photovoltaic (PV) systems under different environmental conditions. Addressing the challenges associated with these connection types is crucial for improving the reliability of solar energy utilization. Accordingly, the significance of electrical faults in PV systems with different array configurations has grown. This study aims to comprehensively evaluate Line-to-Different Line (LDL), Line-to-Line (LL), and Line-to-Neutral (LN) electrical fault types using the Series–Parallel (SP), Total-Cross-Tie (TCT), Bridge-Link (BL), Honey-Comb (HC), SP-TCT, BL-TCT, BL-HC, and HC-TCT PV array connection types on the TMS320F28338 DSP kit based Processor-in-Loop (PIL) platform. To do this, The Reliability Index (RI) and Efficiency Index (EI) are defined and calculated for all possible fault types based on the array’s fault current and generated power. Additionally, the current paths of the system under different fault conditions for eight configuration types are formalized. With this, the electrical fault states of a PV array in any dimension can be easily analyzed with the proposed method, and it will also facilitate the electrical fault analysis of a new PV configuration to be proposed in the future. The results of this work indicate that among the eight configurations, the TCT achieves the highest RI value of 3.59 under all electrical fault types. In contrast, the SP configuration has the lowest RI of 1.28. Conversely, the SP array configuration shows a significantly higher average EI of 81.86%, while the TCT configuration has the lowest EI of 56.56%. These indicate that the TCT configuration is the most reliable under electrical faults; however, the SP configuration is the most efficient. In addition, among the three electrical fault types, the LN fault causes more deterioration in the RI and EI across almost all connection types.