A new shade dispersion technique compatible for symmetrical and unsymmetrical photovoltaic (PV) arrays. (15th June 2021)

• Record Type: Journal Article
• Authors: Pillai, Dhanup S.; Ram, J. Prasanth; Shabunko, Veronika; Kim, Young-Jin
• Is Part Of: Energy. Volume 225(2021)
• Publication Date: 2021-06-15
• Subjects: Array reconfiguration -- Partial shade -- Shade dispersion -- Power enhancement and PV arrays; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2021.120241
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: Partial shade occurrences still prevail as a major obstacle for maximum power generation from photovoltaic (PV) power plants, particularly in urban areas. Therefore, augmenting the power output during such conditions has become a prerequisite in PV installations to guarantee reliable power conversion efficiency. In this context, PV array reconfiguration utilizing physical relocation techniques is a cost effective as well as promising solution. Though many such techniques have been developed in recent times, the applicability of those solutions to real-time power plants is questionable, predominantly due to: 1) incompatibility to unsymmetrical PV arrays, 2) impractical displacement of PV modules to distant columns, 3) necessity of large number of physical relocations, 4) need for lengthy interconnection ties and 5) non-availability of universal relocation rules. In this context, this paper proposes a new reconfiguration technique that can be applied globally irrespective of the size, type, and rating of PV arrays. In principle, the technique evolves from a mathematical concept to arrange PV modules diagonally along the opposite corners of the smallest rectangle that can be developed using squares. Graphically, the proposed technique emulates the vertical downward movement of knights in a chess board. More importantly, the relocation procedure is carefully designed such that each PV module in the array is relocated with in its respective column itself, thereby reducing the overall number of relocations required significantly. Distinctive from existing strategies, the proposed method can be applied to both unsymmetrical and symmetrical PV arrays without any arbitrary assumptions. For validation, extensive simulations considering numerous shade patterns as well as hardware experimentations have been carried out, and the results are compared with prominent techniques available in literature. The results attained show an average instantaneous power difference of 0.3 kW and 0.8 kW respectively for an 8.1 kW system, compared with its counterparts and conventional interconnection schemes. Highlights: An enhanced shade dispersion technique has been conceptualized. The proposed method is compatible for symmetrical and unsymmetrical PV arrays. No arbitrary assumptions are required for real-time implementation. Importance of row current optimization in array reconfiguration is portrayed. The technique is validated by considering six different partial shade test cases.