A novel PV array reconfiguration approach to mitigate non-uniform irradiation effect

Abstract

The extraction of power at global maximum power point (GMPP) has been affected due to non-uniform row-current generation leading to the formation of multiple peaks in power-voltage (P-V) curve. This issue booms out due to set of factors referred to as partial shading condition (PSC). To root-out this issue, puzzle-game based strategies were developed based on physical relocation of shaded modules with the unshaded one. This has a limitation when considering the size as a parameter which is non-effective for larger shade-dispersion. Thus, to alleviate this issue, this research paper intends to execute a novel reconfiguration topology based on idea of permutation and combination (P-C). This novel metaheuristic approach is focussed on building a fitness function in terms of efficiency (Ƞ), fill-factor (FF) and power loss (PLOSS). A connection list has been prepared to evaluate for optimal combination of solar modules. Hence, this approach excels in providing an optimum solar array attenuating the complexity of the photovoltaic (PV) system. The effectiveness of this approach has been validated through MATLAB tool on 4 × 4, 6 × 4 and 9 × 9 solar array size under various shading patterns. To bring out more efficacy, this suggested novel approach has been elaborately compared with traditional Total cross tied (TCT) topology and two other puzzle-based topology Ken-Ken (K-K) and L-shape (L-S) topology for 4 × 4 solar array size on the basis of 16 performance parameters; maximum voltage (VMAX), maximum current (IMAX), GMPP, local maximum power point (LMPP; its values and number of peaks generated on the P-V curve), misleading power loss (MLPL), mismatch loss (MLOSS), current and voltage loss (ILOSS, VLOSS), PLOSS, execution ratio (ER), Ƞ, FF, %power improvement (%PI), thermal voltage (TV) and power enhancement ratio (PER). Results for 4 × 4 solar array size portray that P-C has enhanced GMPP by 5.64 W, 5.64 W and 6.61 W reducing PLOSS by 7%, 6% and 8.26% respectively over L-S, K-K and TCT under border shading. Validation of the novel P-C for 6 × 4 solar array size has been done with TCT and L-S. Its results conclude that GMPP of P-C is incremented by 12.99 W and 0.70 W reducing the PLOSS by 11.16% and 0.99% respectively over TCT and L-S under corner shading. Further, the novel P-C for 9 × 9 solar array size has been validated with TCT, K-K, L-S, Ancient Chinese (A-C) and Skyscraper (S-S) topologies. GMPP of the novel P-C is improved by 16.19 W, 12.34 W, 12.34 W, 12.11 W and 2.75 W minimizing the PLOSS by 5.80%, 5.75%, 5.75%, 5.73% and 4.23% over TCT, K-K, L-S, A-C and S-S under zigzag shading. The comparative results under all the three considered solar array size strongly suggests the increased ability of the proposed novel P-C approach in enhancing the performance parameters and an effective shade dispersion over the entire PV array under PSC as compared to other considered reconfigurations.