Himanshu Sekhar Sahu

Bio: Himanshu Sekhar Sahu is an academic researcher from Indian Institute of Technology Guwahati. The author has contributed to research in topics: Photovoltaic system & Maximum power point tracking. The author has an hindex of 8, co-authored 14 publications receiving 236 citations. Previous affiliations of Himanshu Sekhar Sahu include Shiv Nadar University & Indian Institute of Technology Madras.

Maximizing the Power Generation of a Partially Shaded PV Array

Abstract: As per energy efficiency of a photovoltaic (PV) system is concerned, partial shading is an important issue. Under partial shading condition, the modules of a PV array receive different levels of solar irradiation, so the power generation of a PV system decreases. The power–voltage characteristic of a partially shaded PV array contains multiple local maxima, and the global maximum power point is one of them. The losses in a PV array depend on the shading pattern and the physical location of shaded modules. This paper presents the Futoshiki puzzle pattern for the arrangement of the modules of a PV array under partial shading condition, ensuring the enhancement of the power generation with respect to totally crossed tired (TCT) structure. In this method, the physical locations of modules in a TCT structure PV array are rearranged without changing the electrical connection of the modules. A comparison between the power generation in TCT and Futoshiki puzzle pattern configuration is presented. It is demonstrated that the power generated by a PV array in the Futoshiki configuration method is enhanced, and mismatch loss (ML) is minimized under different shading patterns by theoretical, simulation, and experimental results.

Extraction of Maximum Power From a PV Array Under Nonuniform Irradiation Conditions

Abstract: In this paper, a generalized algorithm for the physical relocation of the modules with a fixed electrical connection (PRM-FEC) in total cross tied (TCT) configuration of an $m\times n$ (where $m$ and $n$ are the number of rows and columns) photovoltaic array is presented for digit $m$ that is either odd or even number This rearrangement of the TCT configuration distributes the shadows over the array, and hence, it increases the power output of an array under partial shading conditions The proposed scheme is simple and cost effective The comparison of power generated by an array with the TCT, electrical array reconfiguration, and the PRM-FEC configuration is performed with MATLAB simulation and also the simulation results are validated with experimental results The performance of the PRM-FEC configuration is superior to the TCT configuration

Power enhancement of partially shaded PV array by using a novel approach for shade dispersion

Abstract: Photovoltaic (PV) arrays produce less power than the array rating due to shading on the array. Since the modules of the arrays receive different solar irradiation, the powervoltage characteristics of photovoltaic (PV) arrays contain multiple local maxima. This paper presents a novel approach to arrange the physical position of modules in Totally Cross Tied (TCT) configuration, without changing the electrical connection of the modules in the array, in such a way that there is an increase of power generation of array under partial shading condition. The modules of TCT configuration are rearranged in such a way that the shading effect is distributed over the array, and it reduces the multiple local maxima in power-voltage characteristics of PV array. Hence tracking of global maximum power point (GMPP) in the present approach is simpler. In this paper, the power generation of array with TCT and proposed configuration is compared. It is demonstrated that the power generation of array with proposed configuration is enhanced under different shading pattern.

Estimation of MPP of a Double Diode Model PV Module From Explicit I–V Characteristic

Abstract: This paper presents a novel approach for the conversion of an implicit current–voltage (I–V) expression of a double diode model (DDM) photovoltaic (PV) module to an explicit expression of current in terms of voltage. A new method is proposed for the estimation of maximum power point (MPP) of a DDM PV module using the explicit I–V expression of a PV module under uniform irradiance condition. Further, a new mathematical model of a partially shaded PV array is developed using the proposed explicit expression. Since the explicit I–V expression is used for the estimation of MPP of a DDM PV module under uniform and nonuniform irradiance conditions, the estimation of MPP is simple, accurate, and efficient. The accuracy of the explicit expression is verified considering three different PV modules. A comparison of MPP of a DDM PV module extracted using the proposed method with different existing methods under different environmental conditions (DECs) is presented. The results obtained using the proposed method are validated with the experimental results under DEC. Also, the accuracy of the estimated global MPP of a PV array under partial shading conditions is verified.

Numerical approach to estimate the maximum power point of a photovoltaic array

Abstract: This study presents a novel approach to estimate the maximum power point (MPP) of a photovoltaic (PV) array on an hourly basis using meteorological data. The estimation of MPP of a PV array based on its characteristic equation is done by using Levenberg-Marquardt (LM) method. The monthly averaged daily and hourly global solar irradiation during sunshine hours of Guwahati city is estimated by taking relative humidity and ambient temperature data using empirical relations. The actual and estimated maximum powers of a PV array of monthly averaged daily and hourly basis is calculated using MATLAB. It is demonstrated that each of the estimated maximum power of a PV array on an hourly basis is nearly equal to each of the actual maximum power. The MPP of a PV module estimated by the LM method is validated with the actual and experimental results. A comparative study of MPP of a PV module estimated from the proposed method with perturb-and-observe based on proportional-integral, genetic algorithm and Gauss-Seidel is performed. The performance of the proposed algorithm for estimation of MPP of a PV array ensures the accuracy and faster convergence.

Particle Swarm Optimization Based Solar PV Array Reconfiguration of the Maximum Power Extraction Under Partial Shading Conditions

Abstract: For large photovoltaic power generation plants, number of panels are interconnected in series and parallel to form a photovoltaic (PV) array. In this configuration, partial shade will result in decrease in power output and introduce multiple peaks in the P–V curve. As a consequence, the modules in the array will deliver different row currents. Therefore, to maximize the power extraction from PV array, the panels need to be reconfigured for row current difference minimization. Row current minimization via Su Do Ku game theory do physical relocation of panels may cause laborious work and lengthy interconnecting ties. Hence, in this paper, an alternative to physical relocation based on particle swarm optimization (PSO) connected modules is proposed. In this method, the physical location of the modules remains unchanged, while its electrical connections are altered. Extensive simulations with different shade patterns are carried out and thorough analysis with the help of I–V , P–V curves is carried out to support the usefulness of the proposed method. The effectiveness of proposed PSO technique is evaluated via performance analysis based on energy saving and income generation. Further, a comprehensive comparison of various electrical array reconfiguration based is performed at the last to examine the suitability of proposed array reconfiguration method.

A review on maximum power point tracking for photovoltaic systems with and without shading conditions

Abstract: This paper discusses maximum power point tracking (MPPT) methods of PV system for normal and partial shading conditions (PSC). The selected MPPT methods were classified as artificial intelligent, hybrid, and other MPPT methods. The comparison of researches on MPPT methods under normal condition and PSC reveals that researchers have concentrated more on shading conditions since the last few years mainly due to the need of power output and efficiency improvements. It is believed that the information contained in this piece of work will be of great use for the researchers in the field under consideration.