PV Array Configuration Research Articles

Review of PV array modelling, configuration and MPPT techniques

ABSTRACT This paper reviews the existing models, connection schemes and maximum power point tracking (MPPT) methods of PV arrays. The partial shading causes significant power losses. It is very difficult to maintain uniform irradiance over the entire PV array, especially for rooftop or building-integrated PV systems. The aspects such as connection scheme of PV array, shading pattern and maximum power point tracking (MPPT) techniques, etc., decide the power generated by the PV array. The conventional MPPT methods are only capable of reaching maximum power point (MPP) in identical insolation situations. Hence, conventional MPP tracking becomes inept due to the existence of several peaks in the P-V characteristics. There are different global maximum power point (GMPP) tracking techniques available in the literature that operate in partial shading scenarios. The reconfiguration of the PV array reduces the number of multiple peaks. This reduction in several peaks makes conventional MPP tracking techniques competent even under partial shading conditions with low implementation complexity and higher tracking speed. This paper can assist scientists in choosing a precise objective-based PV module model, connection schemes and MPP tracking methods out of numerous schemes available in the literature.

An Experimental Investigation on Photovoltaic Array Power Output Affected by the Different Partial Shading Conditions

This paper presents an experimental investigation on photovoltaic array (PV array) power output affected by partial shading conditions (PSCs). An experiment setup of a PV array with a series configuration using 2 × 4 photovoltaic modules (PV modules) was built. The power output loss due to the shading effect on the first photovoltaic cells (PV cell) connected with bypass diodes of each photovoltaic module, installed in the PV array in the horizontal direction, was evaluated. Depending on the direction of the sun relative to the PV array configuration, the shading percentage was measured during the test and recorded the current and voltage of the PV array. The performance evaluation of the PV array configurations is referred to with respect to the values of maximum power voltage, the maximum power current, maximum power output, power output losses and fill factor (FF). The experimental results show that 44% shading of the first PV cells affects PV array power output loss by more than 80%.

High-efficiency swarm intelligent maximum power point tracking control techniques for varying temperature and irradiance

PV systems may suffer significant power loss caused by irregular irradiance patterns and changing temperatures. Moreover, partial shading (PS) is a major defect for existing maximum power point tracking (MPPT) controllers. This paper proposes efficient and robust MPPT controllers using novel Slime mould optimization (SMO) and improved salp swarm optimization algorithm (ISSA) to track GMPP for different PV array configurations. ISSA takes opposition based learning (OBL) and local search algorithm (LSA) to perform maximum exploration of the search space. Due to LSA, the oscillation of ISSA can be reduced to zero. Moreover, a novel SMO MPPT technique is introduced for MPPT tracking of PV systems under various weather conditions. The results of the proposed controllers are compared with those of well-known perturb and observe (P&O), particle swarm optimization (PSO), SSA, and cuckoo search optimization algorithm (CSA) MPPT techniques. Six distinct cases of varying temperature, field atmospheric data study, uniform irradiance, PS, and complex-PS are studied. Results and their analysis confirm that the proposed controllers have the highest transient and steady-state efficiency of up to 99.9% with the least tracking time of up to 130 ms while keeping the oscillation in the steady-state well below 1–2W.

Ecent Advancement on Solar Photovoltaic Energy Generation System Special Reference to Shading Condition- A Review

Design of a Solar PVEnergy Generation to harness the optimum solar energy has been a big challenge among the researcher. It is quite essential to review the latest all the availabletechnique, their advantages and disadvantages, prior to designinga new Solar PV Energy Generation system. In present paper a detail discussion is presented on various maximum power points tracking algorithms employed on Photovoltaic Energy generation system under shading condition. We have covered the various algorithms, PV modelling techniques, PV array configuration, monitoring system etc. up to till date. Impact of shading effect is reported massive on energy supply capacity. Hence, in this paper we have investigated and discussed the various type of PV module at different type of shading level. This paper provides a handy reference to undertake a mass research works on PV system in near future under shading condition

Improvement of Power Acquisition Characteristic on PV Generation System by Using Active PV Array

The PV generation system operates in maximum power of PV array by MPPT control of power conditioning system (PCS). However, there is a problem that maximum power of the PV array configuration greatly decreases by partial shadow. For this problem, the authors previously proposed the active PV array(APV) system which is able to extract total power of the maximum power of each PV panel with preset PV array voltage, equipping each panel with the buck-boost converter(Unit). This APV system is able to maintain the ideal P-V characteristics under all conditions. In this paper, the effect of this method is demonstrated by simulation and experiment. In this investigated condition, it is clarified that the generated power of the proposed APV system is 1.6 times, compared with the conventional PV array system.

Reduced partial shading effect in multiple PV array configuration model using MPPT based enhanced particle swarm optimization technique

The depletion of energy resources are increased day by day, which is the main environmental problem for today's world. Recent development uses solar energy because the photovoltaic cost is less. Nowadays, solar systems reduce the global energy demand using various novel techniques and configurations. However, multiple peaks in the power characteristics curve develop the partial shading effect in the PV array. The main objective of this proposed method is to reduce the multiple peaks in the output power characteristics and reduce the drawback in array configurations since it increases the overall system efficiency. The conventional method uses series, parallel, series to parallel, Total-Cross-Tied, Sudoku pattern and bridge linked PV configurations. All these technique effectively carried out the partial shading of PV array. In this proposed model, the reduced partial shading effect is configured through multiple PV array configurations like series, parallel, TCT, bridge linked and series-parallel. Here with enhanced PSO based MPPT technique is used to optimize the power shading effect in the PV array configurations. Here the PV cells are arranged by PV configuration model and the PV array is developed with various irradiances for knowing the effect of partial shades. The Maximum Power Point Tracking System is used to reduce the multiple peaks in the power curve with enhanced PSO technique. Based on the multiple PV array configurations, the power, voltage and current is measured and the maximum power point is tracked to provide the maximum power range. This PV array configuration is optimized by artificial bee colony algorithm. Here in the MPPT, the PI controller utilizes the controller block and PSO is used to optimize the global and local best possible values. By comparing with the conventional method, the proposed method achieves the result of output voltage, current, power and MPP power peaks. As per the experimental result, the series and series-parallel topology achieves the result upto 90% of circuitry than existing approach. The overall system is done by using MATLAB/Simulink with the adaptation of 2018a.

Performance analysis of DC type variable speed solar pumping system under various pumping heads

This paper proposes a method for the modelling, simulation and analysis of solar PV water pumping system. A submersible type variable speed DC water pump system is considered in this study under different pumping heads (50 m, 60 m and 70 m) and for 8S × 3P PV array configuration. The hourly electrical performance of the PV array was estimated from the maximum power points of the I-V curves, as the maximum power point tracking (MPPT) controller continuously optimizes the output power of the PV array. The performance equation which relates the flow rate of the pump with pump head and power input to the pump is modelled from the manufacturer’s performance curve with curve fitting technique. Using the generated equation and the calculated hourly power output data, the hourly performance of the solar driven water pump system was estimated for of different pump head. The analysis and simulation results show that a lower pump head results in higher flow rate regardless of the variation in solar irradiation level. The obtained result also indicated that an increase in solar radiation intensity resulted in an increasing of the pump flow rate, pump efficiency and system performance.

Performance analysis of PV array configurations (SP, BL, HC and TT) to enhance maximum power under non‐uniform shading conditions

AbstractPartial shading condition (PSC) causes the significant increase in power losses of solar photovoltaic arrays. Partial shading is due to the shadows of passing clouds, chimneys, trees, bird droppings, various tall building structures etc. At the PSCs, the local hotspots are formed in the partially shaded PV modules due to increase in temperature of the shaded module during its operation in reverse bias condition. The hotspots in the PV modules can be avoided by connecting bypass diodes in anti‐parallel to the modules. But due to the functioning of bypass diodes, several peaks are produced in the I‐V and P‐V characteristics. Apart from this phenomenon, the mismatch losses are also arises between the modules with significant reduction in output power from the PV array. The objective of this paper is to model, analyze, simulate and evaluate the performance of 7 × 7 PV array configurations such as Series‐Parallel, Bridge‐Link, Honey‐Comb and Triple‐Tied in the presence of various PSCs. The PSCs considered are corner, center, right side end, bottom side end, L‐shape, frame, random and diagonal shadings. The performance of these configurations under different shading patterns have been compared and analyzed with the performance parameters like open circuit voltage, short circuit current, global peak power (GPP), voltages and currents at GPP, number of local peak powers (LPPs), voltages and currents at LPP, mismatch losses, fill factor and efficiency. All the configurations are simulated by using KYOCERA‐KC200GT PV module specifications.

Energy generation and flow rate prediction of photovoltaic water pumping system for irrigation

This paper aims to present future energy and flow rate generation scenario of conventionally designed photovoltaic water pumping system for irrigation using projected climate change and degradation factor. The mean monthly water flow rate from the pump was predicted for different months using expected power for 16S × 1P PV array configuration. The mean monthly expected power from solar PV system was estimated using climate change forecast of solar radiation and temperature for 30 years of lifetime period of solar PV pumping system. The estimation of expected power at predicted solar radiation and temperature also includes the yearly system components degradation rate. The water flow rates were predicted using an experimentally developed mathematical model for a given pump. The experimental model simulates the water flow rate for various solar power and heads (30 m, 40 m and 50 m). The field data were obtained using a pumping test facility located at a farm site of IIT Kharagpur (India). It was found that the flow rate increases with the increase in pump power for each head. The yearly pattern of predicted energy and flow rate for different months showed a decreasing trend as the projected temperature rise and component degradation reduces the energy yield from the PV array. The results indicated that the overall reduction in the capacity of a PV system is in the range of 25–27% for different months in which climate change (rise in temperature) showed minor effect (3%) and can be neglected. The mitigating measures for energy loss are required to fulfil future irrigation demand.

Intelligence Technique Based Design and Assessment of Photovoltaic-Battery-Diesel for Distributed Generation System in Campus Area

Several studies have discussed the optimal designing methods of distributed generation (DG) based on intelligent algorithms. However, the feasibility of an intelligent algorithm-based DG system has not been investigated further, especially for DG in the campus area. Moreover, the DG that operates in two modes (grid-connected and micro-grid mode) has unique characteristics. This paper presents a design and assessment of the PV-battery-diesel DG system in the campus area based on a powerful intelligence technique. The designed DG consists of a PV system (PV array, battery, and inverter) and a diesel generator is used as backup power supplies to cover the loads during grid blackouts. The intelligence technique is used to determine the optimal size and configuration of PV array. In this work, a new variant modified AHP with fuzzy logic is developed to solve the problem. The developed algorithm is implemented by using MATLAB software. Then, the optimal size and configuration results have been evaluated and assessed in HOMER software. HOMER simulation results show that DG can operate in both grid-connected and micro-grid mode properly. Based on the case study site data, the net present cost of DG system is $291.073,43. The energy cost of the DG system is $0,12 for E6+E8 building system and $0,06 for E11 building system. The DG system has produced some pollutants from fuel consumption.

A novel triple-tied-cross-linked PV array configuration with reduced number of cross-ties to extract maximum power under partial shading conditions

A novel triple-tied-cross-linked PV array configuration with reduced number of cross-ties to extract maximum power under partial shading conditions

Optimal PV array configuration for extracting maximum power under partial shading conditions by mitigating mismatching power loss

The grid-connected or standalone PV central inverter architecture comprises of several PV modules which are connected in different ways to form the PV array. The power generation capability of the PV array is mainly affected by partial shading conditions (PSC). Due to PSCs, the power output of the PV array reduces dramatically, and mismatching losses are induced in the PV modules. To the extent of these problems, the multiple peaks are also appeared in the power-voltage (P-V) curve, which is very complicated to track the global maximum power point (GMPP). The main objective of this research paper is to model and simulate the Series (S), Series-Parallel (SP), Bridge-Link (BL), Honey-Comb (Hc), Total-Cross-Tied (TCt) and proposed Triple-Tied (TT) solar PV array configurations under various partial shading scenarios. The performance of all PV configurations is evaluated under uniform and eight different shading scenarios. The performance of the considered PV configurations is analyzed in terms of their mismatching power losses, fill factors, efficiency, global maximum power points (GMPPs), local maximum power points (LMPPs), voltages and currents at GMPPs, open circuit voltage and short circuit current. The above-mentioned PV configurations are modelled and simulated in Matlab/Simulink environment by considering KC-200GT module parameters.

Sizing a 3 kWp Retrofitted Grid-Connected Photovoltaic System: a Case Study in Tropical Malaysia

The work presents a tropical case study of sizing 3 kWp retrofitted grid-connected photovoltaic system (GCPV) installed in Klang, Malaysia. The sizing was based on customer’s budget requirement of RM 22, 500 and conducted through a designated mathematical approach. The mathematical approach involved technical aspects which aligns the voltage and current specifications of both PV array and inverter. Besides, this approach includes possible severe climatic condition of solar irradiance and ambient temperature variations. By implementing the sizing mathematical approach in this study, the final PV array configuration is 1 x 9 (1 parallel x 9 series). This study was also conducted to compare between the actual and the predicted energy yield to reflect customer satisfaction. Based on the result, the percentage differences are acceptable for February and March 2018. Interestingly, the percentage difference for January 2018 was over-predicted and the abnormality was suggested to be resulted from the inaccuracy of the Peak Sun Hour (PSH) estimation. In conclusion, this study is significant as an overview on the sizing and performance reliability of GCPV system in tropical Malaysia to meet up the customer satisfaction.Â

Performance Analysis of Conventional, Hybrid and Optimal PV Array Configurations of Partially Shaded Modules

In this paper, modeling and performance analysis of conventional configurations are Series-Parallel (SP), Bridge-Linked (BL), Honey-Comb (HC), Total-Cross-Tied(TCT) and proposed hybrid configurations are SP-TCT, BL-TCT, HC-TCT, BL-HC and modified BL(MBL), modified HC(MHC), proposed optimal interconnection type configurations of a 5x5 size solar PV array under ten different partial shading cases it causes shading losses and compare the best configuration with respect to array power, number of interconnections or ties required between shaded modules in the array. The proposed optimal interconnection method reduces the number of ties required between modules and these ties are based on the position of number of shaded modules in the entire solar PV array. For the performance analysis of above 11 configurations, total ten shading cases are considered and compare the result with one un-shaded case-U of an irradiance 1000 W/m2. The PV module parameters of Vikram Solar ELDORA 270 are used for modeling of above 11 conventional and proposed PV array configurations and simulate the models in MATLAB/ Simulink software.

Enhancement of maximum power output through reconfiguration techniques under non-uniform irradiance conditions

Partial shading is one of the major drawback which diminishes the power output of the PV array. One of the effective methodologies is reconfiguration strategies, namely shifting the location of PV modules from one place to different places so as to distribute shading effects over the array to increase maximum power output under PSCs. This paper proposed two novel puzzle arrangements followed by Ken-Ken (KK) and Skyscraper (SS) for 4×4 total-cross-tied (TCT) PV array and increase maximum power under PSCs. In this approach, the PV modules in the TCT array is arranged according to Ken-Ken and Skyscraper arrangements without changing the electrical connections. Further, the performance of the proposed arrangements are investigated with different existing PV array configurations by comparing the global maximum power point (GMPP), the voltage at global maximum power point (VGMPP), mismatch losses (ML), fill-factor (FF), efficiency (η) and possible local peaks (PLP) under different shading patterns using Matlab-Simulink. An extensive simulation study is carried out on these configurations under different shading patterns as well as temperatures. Also, a comprehensive comparison has done for various reconfiguration schemes presented in literature. The result shows that the proposed arrangements are enhancing the global maximum power as compared to the other existing configurations.

Power acquisition effect for appropriate placement of MPPT units in a PV array

The PV generation system operates in maximum power point of PV array by MPPT control of power conditioning system (PCS). However, there is a problem that maximum power of the PV array configuration greatly decreases by partial shadow. For this problem, the authors previously proposed the method which connects MPPT unit to every PV panel between PCS and PV array. Moreover, the effect of this method was demonstrated by simulations and experiments. In the present day, this method is in practical use. However, the appropriate placement of MPPT units was still not clear. The authors previously investigated the appropriate placement of MPPT units from the viewpoint of acquisition of electric power and system stability, simulating P-V and I-V characteristics of some representative patterns connected MPPT unit to each PV panel in the PV array configuration. In this paper, power increase rate of the proposed PV array system is evaluated in experiment, compared to the conventional PV array system. It is clarified that maximum power of the proposed PV array system is 1.26 times, compared with maximum power of the conventional PV array system.

Interpretation of MPPT Techniques in Grid Connected Solar PV Array System

Solar energy is one of the most used and readily available renewable energy sources among the other energy sources. The power generated by PV systems is dependent on solar irradiance and temperature parameters. In the literature, many researchers and studies are interested in estimating true maximum efficiency point for the PV systems. Due to that fact, MPPT applications and techniques become an important issue for PV systems under both uniform and non uniform conditions. Although, PV system under uniform environment has only one maxima point on P-V curve which is simple to estimate correctly by conventional MPPT techniques, it is not as simple as under non-uniform condition such as partial shading and mismatch effects. To overcome the drawbacks of the conventional MPPTs under non uniform condition, researchers has been investigated new soft computing MPPTs, PV array configurations, system architectures and topologies.

System-level reliability enhancement of DC/DC stage in a single-phase PV inverter

This paper studies the impact of modulation scheme, mission profile and PV array configuration on the reliability of a double-stage single-phase PV inverter. A single-phase double-stage inverter with two boost-based Maximum Power Point Tracker (MPPT) is considered and the reliability of dc/dc stage is estimated under different mission profiles. Furthermore, two types of PV panels with different output characteristics are considered to demonstrate the impact of PV array design on the PV converter reliability. Moreover, a phase shifted-switching scheme for the dc/dc converters and inverter is proposed to improve the overall reliability. The outcome is the PV converter reliability enhancement through suitable PV panel selection and proposed phase-shifted modulation scheme, which can be a system-level design for reliability guideline for PV converter and PV system designers.

Line losses reduction techniques in puzzled PV array configuration under different shading conditions

The SuDoKu puzzled (SDKP) configuration is a technique to magnify the execution of PV array due to the occurrence of partial shading conditions (PSCs) but more wiring losses exit in this array. This paper focuses on both in terms of power enhancement and wiring loss reduction of PV arrays under PSCs. Moreover, performance of the existing SDKP configuration is contrasted with the proposed Latin Square puzzled (LSP) and Ken-Ken Square puzzled (KKSP) based configurations to moderate the effects of shading situations. An investigation is carried out based on considered various ranges of shading situations such as short narrow, long narrow, short wide and long wide in terms of power generation, power dissipated, execution ratio and fill factor of PV arrays. Further, it is shown that power generation in the proposed configuration is 6.81% more as compared to SDKP configuration. The wiring loss is found to be 18.86% minimum while power loss is 771 W less in the proposed configuration as compared to SDKP configuration under the considered shading situations. Overall, execution of the proposed KKSP configuration is found to be superior to the SDKP configuration.

Mathematical puzzle based PV array configuration for GMP enhancement under non-uniform irradiation

The performance exploration of the proposed PV array configurations is analysed during the shadowing conditions. The performance evaluation of total-cross-tied (TCT) and symmetric matrix-total-cross-tied (SM-TCT) pattern based electrical connections are assessed according to distinguish shadow test cases. The PV system's non-linear conduct is noted in terms ofI-V and P-V curves. During partial shading conditions (PSCs), multiple power points (MPP) are observed such as local MPP and global MPP. Both TCT and SM-TCT configurations are compared in terms of parameters Global MPP, fill factor (FF) and performance enhancement (PE) under the three distinct shadow test cases as (i) lamp post (ii) three cornered shading or structure shadow (iii) single vertex shading respectively.