Impact Of Partial Shading Research Articles

Effect of Partial Shading on a PV Array and Its Maximum Power Point Tracking Using Particle Swarm Optimization

The maximum power point (MPP) of a Solar Photovoltaic (SPV) array varies with temperature and irradiation. Shadow of various objects falling on a certain portion of the SPV array causes partial shading condition (PSC) which results in the formation of hot spot. Thus, reducing the power (output) by 33% on a single cell in addition to the occurrence of various peaks on a P-V curve. To detect global maxima among the multiple peaks is a challenge for researchers. Hence, different Maximum Power Point Tracking (MPPT) techniques are used to overcome this challenge. In this paper, the impact of partial shading on SPV array has been analysed and the Particle Swarm Optimization (PSO) based MPPT technique is used to obtain global maxima under partial shading conditions. The MPPT controller is incorporated with a converter (boost) to vary the input voltage as per the duty cycle of the switch generated by PSO algorithm-based controller.

Impact of Partial Shading on Various PV Array Configurations and Different Modeling Approaches: A Comprehensive Review

Since the last decade, partial shading conditions (PSCs) and its adverse influences on photovoltaic (PV) system performance have received due attention. It motivates researchers to explore methods to diminish/disperse the shading effects and/or novel PV array configurations to sustain under PSCs. To diminish the effects of PSCs, this article presents a comprehensive review of various PV array configuration models for PV systems and metaheuristic approaches for shade dispersion effectively. Different PV array modeling approaches are identified, emphasizing their benefits, inadequacies and categorized according to vital features such as shade dispersion and improved performance in terms of efficiency; fill factor (FF), and maxima power, minimized power losses (PL) primarily. Besides these various PV array configurations such as hybrid, reconfigured, mathematical/game puzzle based advanced configurations are uniquely discussed with the existing configurations. In the current scenario, the metaheuristic algorithms are explored and widely accepted by researchers due to the less wire length requirement for PV array reconfiguration. This article discusses and deliberates recent developments in methods of solar PV performance enhancement that deserves further study. Overall, the present study is helpful for academicians and researchers in the committed solar power installation area.

Comparison of Half-Cell and Full-Cell Module Hotspot-Induced Temperature by Simulation

The impact of partial shading on cell operating current, voltage, and temperature is simulated, for a half-cell module with series–parallel–series connections and for the conventional full-cell module. When shaded, we find the half-cell modules comprising two parallel 60-half-cell strings benefit from a reduced heat dissipation compared to a 60-full-cell series connected design. The maximum hotspot cell temperature of the shaded half-cell module is 28 °C lower than that of the full-cell module. Our result suggests that half-cell module design could mitigate hotspot degradation or failure in crystalline-silicon photovoltaic modules.

Identification of partial shading in solar panels using genetic algorithms, simulated annealing, and particle swarm optimisation

The paper presents an optimisation-based methodology to identify the partial shading condition in solar panels feeding voltage-source inverter (VSI) induction motor drives. Performance characteristics of the panel are used to determine the shading factor and number of shaded modules. An optimisation problem is formulated and solved independently by genetic algorithms (GA), simulated annealing (SA), and particle swarm optimisation (PSO) techniques. The proposed method is able to distinguish between partial shading operation and uniform reduction of solar irradiation on the whole panel. Results show the effectiveness of the proposed method to identify partial shading of solar panels. A comparison study shows that PSO obviously outperforms both GA and SA in partial shading identification, especially in robustness and convergence time. The impact of partial shading on the operation of the induction motor drive and water pump load is found minor.

Improvement in Energy Harvest of Solar Photovoltaic Systems under Partial Shaded Conditions

Partial shading is the major contributing factor for reduced energy harvest in building integrated or rooftop photovoltaic (PV) systems. The architecture of the PV array is altered dynamically in accordance with shade intensity to alleviate the impact of partial shading. However, this technique demands more number of sensors, switches and a sophisticated control algorithm. In small urban residential installations, the shade is often caused by trees and structures in the same or nearby buildings and is inevitable due to space limitations. The shape and intensity of the shade does not vary rapidly in these cases and hence dynamic reconfiguration is not necessary. The paper addresses the issue by proposing a simple tailored architecture to enhance the output under shaded conditions without using additional sensors and switches. The location of the panels in an array is predetermined in the proposed work in such a way that the shade is evenly distributed all over the array. This reduces the mismatch losses and enhances the output. For utility purposes, asymmetric multilevel inverter controlled by FPGA (Field Programmable Gate Array) is employed and the results are presented.

The Impact Mitigation of Partial Shading on PV Array Power Generation

The impact of partial shading on photovoltaic (PV) array is discussed in this paper. The partial shading on PV array can significantly decrease the power generation of PV array. This study examines the modeling of PV module which relates with solar irradiation, temperature, and shading pattern. There are different shading patterns on PV array, such as one-string shading, two-strings shading, and much more. The characteristics of current-voltage (I-V) and voltage-power (V-P) curves for each individual the PV array can be different dependent on the multiple MPPs, maximum power points (MPPs). These multiple MPPs are basically lower than the MPP in case of no shading. Therefore, the total generated energy in an interested time period is usually reduced. As a result, this paper proposes the appropriate arrangement of PV modules in a PV array in order to mitigate the impact of partial shading. Finally, the proposed arrangement of PV modules is tested in a testing system. All the obtained results confirms that the proposed arrangement of PV modules is effective and can be applied in practice.

Adaptive-fuzzy detection and assessment of partial shading in solar panels feeding induction motor drives

The paper presents a methodology based on adaptive neuro-fuzzy inference systems (ANFIS) for the detection and assessment of partial shading conditions in solar photovoltaic (PV) panels. The impact of partial shading on the operation of the induction motor drive load is also studied. The solar panel is modelled under normal and partial shading conditions for performance comparison. Three ANFIS agents are designed, trained, and tested for full identification of the partial shading condition. One ANFIS agent detects the initiation of partial shading, another agent determines the shading factor, and a third agent infers the number of shaded modules of the panel. Results show excellent performance of ANFIS on the detection and assessment of partial shading. Impact on the induction motor drive operation is found insignificant.

Impact of partial shading on the output power of PV systems under partial shading conditions

A major challenge in the photovoltaics (PV) systems is to make it energy efficient. Partial shading reduces the energy yield of PV systems and introduces multiple peaks in the P - V characteristics. The maximum power point trackers (MPPTs) work in conjunction with the boost converter and track the global peak in the P - V characteristics. The boost converter used for MPPT is generally designed to operate with high efficiency at the maximum power point (MPP) voltage of the array by assuming a single peak power point on the P - V characteristics. However, the efficiency of the boost converter varies with the input voltage, and the MPP of the load when the converter efficiency is considered is different from the MPP of the PV array. Since the maximisation of power in the load is ultimately desirable, this study focuses on the maximisation of power to the load. The power transferred to load under different shading patterns is analysed and the results of the study are demonstrated through simulation and experimental results.