Evaluation of Interconnection Configuration Schemes for PV Modules with Switched-Inductor Converters under Partial Shading Conditions

Kamran Ali Khan Niazi,Mashood Nasir,Yongheng Yang,Dezso Sera

doi:10.3390/en12142802

Kamran Ali Khan Niazi, Mashood Nasir + Show 2 more

Open Access

https://doi.org/10.3390/en12142802

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Abstract

Partial shading on photovoltaic (PV) arrays reduces the overall output power and causes multiple maximas on the output power characteristics. Due to the introduction of multiple maximas, mismatch power losses become apparent among multiple PV modules. These mismatch power losses are not only a function of shading characteristics, but also depend on the placement and interconnection patterns of the shaded modules within the array. This research work is aimed to assess the performance of 4 × 4 PV array under different shading conditions. The desired objective is to attain the maximum output power from PV modules at different possible shading patterns by using power electronic-based differential power processing (DPP) techniques. Various PV array interconnection configurations, including the series-parallel (SP), total-cross-tied (TCT), bridge-linked (BL), and center-cross-tied (CCT) are considered under the designed shading patterns. A comparative performance analysis is carried out by analyzing the output power from the DPP-based architecture and the traditional Schottky diode-based architecture. Simulation results show the gain in the output power by using the DPP-based architecture in comparison to the traditional bypassing diode method.

Highlights

Solar energy is free and abundant [1]
The output power produced by PV arrays is remarkably reduced due to partial shading conditions [5,6]
The current from the PV array is constrained by the shaded PV modules, which in turn is detrimental for the other healthy PV modules connected in the series [10]

Summary

Introduction

Solar energy is free and abundant [1]. Environmental concerns are widely reduced by using solar energy for power generation. In addition to developing advanced MPPT algorithms, an alternative is to directly mitigate the local peaks under partial shading. Differential power processing (DPP) converters [20,21,22,23,24,25] are typical local peaks under partial shading. Differential power processing (DPP) converters [20,21,22,23,24,25] are typical representatives, that enable each PV module to produce maximum output power. DPP converters representatives, that enable each PV module to produce maximum output power. Working principle of the PV–PV DPP is shown in Figure 3b,c, where the PV module M1 is shaded. Switched-inductor (SL)-based voltage balance converter [20]:

Switched-inductor

Configurations and Shading Pattern Designs

Long Narrow Shading

Results and Discussion

Conclusions