Standalone Solar Photovoltaic Research Articles

Modeling and Control of Solar PV with Battery Energy Storage for Rural Electrification

In rural areas where electric power grid network is rarely available, power generation from renewable energy resource such as solar photovoltaic (PV) is mostly accomplished in standalone mode. The standalone solar PV system requires energy storage device to achieve reliable power supply to the end users. This paper presents modelling and coordination control of solar PV with battery energy storage system (BESS) for rural-electrification applications. The proposed control is accomplished via a bidirectional buck-boost converter with the objective of maintaining voltage at the DC bus constant. Simulation results based-on MATLAB/Simulink platform confirms good performance of the proposed system.

Multi-Objective Optimum Design of Hybrid Renewable Energy System for Sustainable Energy Supply to a Green Cellular Networks

A hybrid solar photovoltaic (PV)/biomass generator (BG) energy-trading framework between grid supply and base stations (BSs) is proposed in this article to address the power crisis of the utility grid, to enhance energy self-reliance, and to downsize the cost. The optimal size, technical criteria, energy generation, and different types of costs have been evaluated considering the dynamic behavior of solar radiation, traffic arrival intensity, and average biomass energy potential. Additionally, the wireless network performance in terms of total achievable throughput, spectral efficiency (SE), and energy efficiency (EE) are extensively examined using the MATLAB-based Monte-Carlo simulations taking multipath fading, system bandwidth, transmission power, and inter-cell interference (ICI) into consideration. The numerical results demonstrate that the energy-trading facility can achieve net present cost (NPC) and greenhouse gas saving up to 3.20% and 65.8%, respectively. In the end, the performance of the hybrid solar PV/BG system has been thoroughly compared with the standalone solar PV, hybrid PV/wind turbine (WT), and hybrid PV/diesel generator (DG) systems under on-grid and off-grid configurations for benchmarking.

Design and Simulation of High-Gain DC-DC Converter using P&O Algorithm with Bi-Directional Converter for Minimum Voltage Standalone Solar PV System

The inexhaustible source of energy which produced from sun through radiation and it is readily available source at free of cost. Solar Photo Voltaic (PV) systems are used as a primary source to produce power. The solar PV system needs DC-DC converter with enhanced voltage gain as well as efficiency. A typical DC-DC converter provides constrained gain and productivity as increase in requirements. For organization of battery Bidirectional converter is used which allows the energy flow in both the direction. The complete working of below voltage PV system and battery that is used are worked by using various dc converters from which the efficiency and gain level can be improved. Maximum Power Point Tracking (MPPT) is employed to receive peak power from solar PV by sustaining DC line voltage and satisfy power requirements. The perturb and observe (P&O) algorithm is mostly used to obtain the high voltage from solar PV. The entire framework is designed and simulated using MATLAB-Simulink toolbox.

Optimum Design of a Standalone Solar Photovoltaic System Based on Novel Integration of Iterative-PESA-II and AHP-VIKOR Methods

Solar energy is considered one of the most important renewable energy resources, and can be used to power a stand-alone photovoltaic (SAPV) system for supplying electricity in a remote area. However, inconstancy and unpredictable amounts of solar radiation are considered major obstacles in designing SAPV systems. Therefore, an accurate sizing method is necessary to apply in order to find an optimal configuration and fulfil the required load demand. In this study, a novel hybrid sizing approach was developed on the basis of techno-economic objectives to optimally size the SAPV system. The proposed hybrid method consisted of an intuitive method to estimate initial numbers of PV modules and storage battery, an iterative approach to accurately generate a set of wide ranges of optimal configurations, and a Pareto envelope-based selection algorithm (PESA-II) to reduce large configuration by efficacy obtaining a set of Pareto front (PF) solutions. Subsequently, the optimal configurations were ranked by using an integrated analytic hierarchy process (AHP) and vlsekeriterijumskaoptimizacija i kompromisonoresenje (VIKOR). The techno-economic objectives were loss of load probability, life cycle cost, and levelized cost of energy. The performance analysis results demonstrated that the lead–acid battery was reliable and more cost-effective than the other types of storage battery.

Dynamic life cycle economic and environmental assessment of residential solar photovoltaic systems

With the increasing implementation of solar photovoltaic (PV) systems, comprehensive methods and tools are required to dynamically assess their economic and environmental costs and benefits under varied spatial and temporal contexts. This study integrated system dynamics modeling with life cycle assessment and life cycle cost assessment to evaluate the cumulative energy demand, carbon footprint, water footprint, and life cycle cost of residential grid-connected (GC) and standalone (SA) solar PV systems. The system dynamics model was specifically used for simulating the hourly solar energy generation, use, and storage during the use phase of the solar PVs. The modeling framework was then applied to a residential prototype house in Boston, MA to investigate various PV panel and battery sizing scenarios. When the SA design is under consideration, the maximum life cycle economic saving can be achieved with 20 panels with no battery in the prototype house, which increases the life cycle economic savings by 511.6% as compared to a baseline system sized based upon the engineering rule-of-thumb (40 panels and 40 batteries), yet decreases the demand met by 55.7%. However, the optimized environmental performance was achieved with significantly larger panel (up to 300 units) and battery (up to 320 units) sizes. These optimized configurations increase the life cycle environmental savings of the baseline system byup to 64.6%, but significantly decrease the life cycle economic saving by up to 6868.4%. There is a clear environmental and economic tradeoff when sizing the SA systems. When the GC system design is under consideration, both the economic and environmental benefits are the highest when no battery is installed, and the benefits increase with the increase of panel size. However, when policy constraints such as limitations/caps of grid sell are in place, tradeoffs would present as whether or not to install batteries for excess energy storage.

Investigation of Standalone Solar Photovoltaic Water Pumping System With Reduced Switch Multilevel Inverter

Solar photovoltaic powered water pumping systems are becoming very successful in regions where there is no opportunity for connecting the grid. The photovoltaic technology converts solar energy into electrical energy for operating DC or AC motor-based water pump. In the case of a solar AC motor water pump, it engages two energy conversion stages (DC-DC and DC-AC) in the power conditioning unit. This usually resulted in increased size, cost, complexity and decreases efficiency of the entire system. In addition, the existing two-level inverter (DC-AC) stage generates higher harmonics in output voltage that deteriorates AC motor performance. As a consequence, a single energy conversion stage with more than two-level output voltage could be possible by utilizing multilevel inverters which replaces two-level inversion stage easily to get higher levels of output voltages as well for extracting best results from the motor. Moreover, they can able to operate with reduced switching frequency that certainly reduces switching losses. Still, the increased voltage levels comprise a higher number of power semiconductor switches, cumulative voltage stress and switching losses are making the system more complicated. In this paper an innovative seven-level inverter with five switches had been taken to investigate 0.5 H. P single phase induction motor water pump. This topology ensures minimum switching losses, lowering size along with less installation cost. In order to provide better insight into the working and performance of this proposed topology the simulation results performed in the MATLAB / Simulink environment and hardware implementation are depicted.

Single Stage Autonomous Solar Water Pumping System Using PMSM Drive

This article presents a single stage standalone solar photovoltaic (SPV) array fed water pumping system using a permanent magnet synchronous motor (PMSM). The vital contribution of this work includes: 1) development of the novel modified vector control, which improves the torque response of the system, 2) development of a novel single stage variable step size incremental conductance technique, which provides a fast maximum power point tracking and eliminates the need of intermediate stage dc–dc converter, and 3) introduction of SPV power feed-forward term, which accelerates the overall response of the system under dynamic conditions. This system includes a SPV array, a three-phase voltage source inverter (VSI), a PMSM and a pump. The SPV array converts solar energy into electrical energy. The VSI acts as power processing unit, which supplies desired currents to drive the PMSM. As the PMSM rotates, the pump coupled to the motor accomplishes the objective of water pumping. This system is modeled and simulated using MATLAB/Simulink with available simpower system toolbox and the behavior of the system under varying atmospheric conditions are validated experimentally on a developed prototype in the laboratory.

Design and Optimized of Solar PV System a Case Study of KIOT Administration Offices

Design and optimized of solar PV system is a leading trend in modern energy management of distribution system. In modern or currently most of the life, customers take in energy from different sources like, sunlight, wind, diesel, biomass, even batteries and from main grid of electric power and facilitate not only its conversion into electric energy, but also the demand management, storage and generation association with the system’s output. In recently distributions generations (micro grid) implementations combine loads with sources, allow for intentional islanding and try to use the available waste heat. These solutions rely on complex communication and control, and are dependent on key components and require extensive site engineering. This paper focuses on the design, optimization and simulation of 48-V rated stand-alone solar PV using HOMER software that is suppling primarily by photovoltaic (PV) panels and using battery and diesel for comparison, but which also has the capability to tie in to a main electrical grid. A system of this size should be able to supply power for KIOT administration office buildings. The most important objectives of this paper are the selections of an appropriate PV array, the selection or design of a charge controller and the design of the system’s renewable energy converter.

Design and Development of Standalone Solar Photovoltaic Battery System with Adaptive Sliding Mode Controller

In this paper, a solar photovoltaic-battery located standalone system is proposed. The configuration of bidirectional buck-boost converter has been proposed for charging (buck) and discharging (boost) the battery storage system. Due to solar energy sources irregular nature and variations in load demand, DC micro grids mostly depend on control methods to overcome with DC link voltage variations and power stability. Adaptive sliding mode controller with washout filter is applied due to its good strength for unexpected change of energy resources and loads. This system includes a solar photovoltaic array basis on maximum power tracking from PV, boost converter to maximize power from the PV. A bidirectional DC-DC buck-boost converter is proposed being charging battery in buck mode and discharging battery in boost mode. Incremental conductance implemented to obtain maximum power from photovoltaic array. In this paper, study of comparison between proportional-plus integral method and sliding mode control method with washout filter has been also simulated in the MATLAB using Simulink and the Sim Power System toolbox.

Power Quality Performance Evaluation of Multilevel Inverter With Reduced Switching Devices and Minimum Standing Voltage

Multilevel inverters (MLIs) have been extensively employed to improve the power quality of the photovoltaic (PV) systems. However, the need for large number of components, higher standing voltage, and high harmonic content in the output of a conventional MLI greatly affects the system efficiency. Asymmetrical MLIs have been therefore developed as a suitable alternative to address these issues. This article aims at developing such a hybrid asymmetrical structure suitable for PV application that has a high level per component ratio and minimum standing voltage. The proposed MLI is assembled using a reduced switch H-bridge-based (RSHB) MLI structure with n asymmetrical repeating units and different level doubling circuit (LDC) combinations. The two dc sources used in the repeating units are in the ratio of 1: n voltage ratio, and using n such units, the proposed MLI structures, i.e., PS1 and PS2 can synthesize 4 n + 5 and 4 n + 7 levels, respectively, at the output instead of 2 n + 3 levels with only RSHB MLI. Comparative analysis reveals that both PS1 and PS2 have fewer switches, low standing voltage, less power loss, and lower cost. A 3.9-kW standalone solar PV system is considered for performance evaluation of the PS1 structure applying both the selective harmonic elimination and carrier-based pulsewidth modulation control schemes. In light of this, dc-link voltage balancing and self-voltage balancing mechanism of the LDC are warranted. Extensive simulation of the proposed MLI is performed in MATLAB/Simulink platform under a change in modulation index, sudden load change, frequency change, and step change in solar insolation. Furthermore, theoretical and simulation findings are validated experimentally by performing similar tests on a prototype of the proposed 17-level MLI.

Design and Modeling of Solar Photovoltaic System Using Seven-Level Packed U-Cell (PUC) Multilevel Inverter and Zeta Converter for Off-Grid Application in India

DOI : 10.26650/electrica.2019.18053 In the present study, standalone operation of the solar photovoltaic system with storage is evaluated with the recently introduced seven-level packed U-cell (PUC) multilevel inverter. Zeta converter is used to regulate the output voltage of the photovoltaic (PV) array with the help of the MPPT algorithm. Level-shifted modulation scheme is applied for the PUC inverter. The standalone operation is taken into consideration keeping in view the application/penetration of the solar PV system in remote areas. The Ministry of New and Renewable Energy (MNRE), Government of India has set up the plan to establish the standalone solar PV system for off-grid application in the regions to meet the power requirement of those communities and regions that are difficult to connect with the grid. The climatic condition in the central and western parts of India is conductive for solar PV generation. In contrast to the other well-known inverter topologies, such as neutral point clamped, flying level capacitors, and cascaded H-bridge, among others, PUC inverter requires the least number of switches and capacitors for the same output levels. The system is modeled in the MATLAB®/Simulink using the Waaree Energies WSM-315 modules to supply a load of 2 kW. To optimize the solar PV-based system, incremental conductance optimization technique is used. Cite this article as : Azeem A, Ansari MK, Tariq M, Sarwar A, Ashraf I. Design and Modeling of Solar Photovoltaic System Using Seven-Level Packed U-Cell (PUC) Multilevel Inverter and Zeta Converter for Off-Grid Application in India. Electrica, 2019; 19(2): 101-112.

Second law analysis of the 160 Wp standalone solar photovoltaic system

ABSTRACTThe demand for solar photovoltaic (SPV) systems is growing all over the world due to the continuous increase in the cost of conventional means of power. India has the advantage of around 300 clear sunny days in a year. However, the biggest problem is conversion efficiency. In this paper, an attempt has been made for evaluating the second law efficiency of 160 Wp stand-alone SPV systems installed in RKGIT Ghaziabad premises. The performance of a SPV system depends on climate conditions like temperature, air velocity and a number of sunny days. The solar energy striking the solar panels gets converted into electric and thermal energy. In this work, we have considered the effect of ambient temperature and air velocity on the efficiency of solar panels. The average second law efficiency of SPV systems was found to be 10.7%, whereas maximum second law efficiency was 13.8% at 9am on the same day. The efficiency of the SPV system can be improved by maintaining the temperature of the module.

Modeling of Energy Performance of Stand-Alone SPV System Using HOMER Pro

Stand-alone solar photovoltaic (SA-SPV) systems are attractive option for rural electrification programs in many countries. These systems are invariably provided with battery energy storage (BES) for using stored electricity during nighttime. Availability of bi-directional power electronic converter promises to enhance application of these SA-SPV systems for generating, storing and feeding electricity to local micro-grids. Further, the advantages of such systems can be maximized by minimizing energy losses at different sub-system levels in the system. In the present work, we demonstrate use of HOMER Pro simulation software for simulation of energy performance of SA-SPV (6.75 kWp) system installed in Renewable Energy Systems Laboratory in our Institute, aiming at quantitative estimation of energy losses due to stand-alone mode of operation. The system is provided with battery energy storage (800 Ah) that is used for supplying electricity for night time street lighting on campus up to eleven hours per day. The results of simulation show that when the existing SA-SPV system is upgraded to grid-tied SPV system, by incorporating bi-directional converter, the system will produce total 11086 kWh annually at the site, out of which 4536 kWh will be fed to the local single-phase micro-grid, which accounts for energy lost if the system continues to operate as SA-SPV system.

Experimental Implementation of an APC With Enhanced MPPT for Standalone Solar Photovoltaic Based Water Pumping Station

In this paper, a new active power control (APC) with enhanced maximum power point tracking (MPPT) algorithm are implemented to improve the performances of a solar photovoltaic system (SPV) based standalone water pumping station. The APC uses proportional resonant controller with antiwindup (AWPRC) for ac voltage regulation without saturation phenomena and with high power quality at the point of common coupling. Furthermore, the proportional resonant controller design method for optimal gains to achieve high performance during transition period in terms of phase margin and desired settling time is analyzed. To achieve the MPPT with less oscillation while protecting the battery energy storage system from overvoltage, an enhanced power ratio variable step based perturbation and observation algorithm is used. The effectiveness of the developed control strategies are validated through simulations and experimental results.

Modelling the impact of market imperfections on farm household investment in stand-alone solar PV systems

Abstract Access to electricity in rural Sub-Saharan Africa, where livelihoods are predominantly based on small scale farming, is significantly low. Extending centralised national electricity grids to these rural areas faces significant technical and financial constraints. As a result, many see household-financed decentralised technologies such as small standalone solar photovoltaic (PV) systems as being important for achieving greater electricity access. However, rural farm households typically face a range of market imperfections including lack of access to credit, investment irreversibility (or absence of second-hand markets) and farm production/income risk which act as barriers to their ability and/or willingness to invest. This paper examines how these market imperfections impact on the adoption of standalone solar PV systems for small scale farm households in Uganda. We consider how temporary or permanent these barriers to adoption are when farm production/income is uncertain. We do so by using a dynamic programming model which captures household investment in small scale solar PV systems where significant positive benefits arise through assumed improved farm productivity or income effects, while allowing for credit constraints, investment irreversibility and income risk. Although strong positive incentives exist in the model to adopt a solar PV system, the results show that adoption rates are substantially lower for credit constrained households, with only 40% of these households adopting immediately, compared with over 70% of credit unconstrained households. While these adoption rates do increase over time, only 60% of credit constrained households have adopted within 5 years compared with nearly all credit unconstrained households adopting within the same time period. In the longer term for almost 30% of households the credit constraints act as a permanent barrier to adoption. The presence of a well-functioning second-hand market does increase household consumption and welfare but the impacts on overall adoption rates are rather small.

Operational Testing of Rooftop SA-SPV System in Coastal Tropical climate of India

In the present work, we report results of operational testing of a rooftop stand-alone solar photovoltaic (SA-SPV) system of capacity 6.75 kWp over a period of one year. The performance is measured in terms of daily energy yield from SPV array, daily energy output from the battery energy storage (BES) and the inverter. The system's gross annual energy yield is 6069.68 kWh, and corresponding daily average energy yield is 16.58 kWh/day. The annual average reference yield, array yield and final yield of the system are 5.47 h/d, 2.44 h/d and 2.38 h/d, respectively. The annual performance ratio (PR) and capacity utilization factor (CUF) of the system are computed as 43.58% and 10.24%, respectively. The PR of the SA-SPV system is compared with other SA-SPV systems located in different climatic regions.

Performance Evaluation of a Standalone Solar PV System for Electricity Generation in an Estate

This work focuses on the performance evaluation of a Standalone Solar Photovoltaic (PV) system for electricity generation in an estate requiring a daily power consumption of 50KW. This was achieved through a solar tracker software/hardware – embedded programme control system. A programmable microcontroller (PIC16F877A), light detection sensors (CDS NORP 12), motor driver IC (L293D), power relays (NTE-R22-5) and a dc gear motor with linear actuator (HARL-3618) were used. MikroC Pro compiler from Mikro Electroniker was used to programme the PIC16F877A. A fixed PV panel of same size was placed side by side and tested with the solar tracking system. The test results obtained showed that the solar tracking system produced 14.3W at 8:00am, increases to a maximum of 25.83W at 1:00pm and decreased to 16.28W at 6:00pm while the fixed PV panel produced 5W at 8:00am, increased to a maximum of 25.62W at 1:00pm and decreased to 10.6W at 6:00pm. These results gave the solar tracking system an efficiency increase of 33 percent over the fixed system. The designed system installed in residential homes has capacity to guarantee sustainable, durable and improved power supply.

Energy Balance Control of a Cascaded Multilevel Inverter for Standalone Solar Photovoltaic Applications

This paper presents a clock phase-shifting (CPS) energy balance control (EBC) method for cascaded half-bridge multilevel inverters in standalone solar photovoltaic (PV) systems. It is based on the conservation of energy in each cascaded unit. By shifting the phase of the clock pulse of each cascaded unit, a staircase-like output voltage is obtained. The CPS EBC not only regulates the staircase-like output voltage of the cascaded multilevel inverters accurately under static conditions, but also suppresses the fluctuations of DC sources and improves its dynamic responses to load steps. Thus, the problems existing in solar PV systems using the cascaded multilevel inverters are avoided. Results obtained from simulations and experiments are presented to verify the feasibility and advantages of the proposed control method.

Daily Clearness Index Profiles Cluster Analysis for Photovoltaic System

Due to various weather perturbation effects, the stochastic nature of real-life solar irradiance has been a major issue for solar photovoltaic (PV) system planning and performance evaluation. This paper aims to discover clearness index (CI) patterns and to construct centroids for the daily CI profiles. This will be useful in being able to provide a standardized methodology for PV system design and analysis. Four years of solar irradiance data collected from Johannesburg (26.21 S, 28.05 E), South Africa are used for the case study. The variation in CI could be significant in different seasons. In this paper, cluster analysis with Gaussian mixture models (GMM), K -Means with Euclidean distance (ED), K -Means with Manhattan distance, Fuzzy C -Means (FCM) with ED, and FCM with dynamic time warping (FCM DTW) are performed for the four seasons. A case study based on sizing a stand-alone solar PV and storage system with anaerobic digestion biogas power plants is used to examine the usefulness of the clustering results. It concludes that FCM DTW and GMM can determine the correct PV farm rated capacity with an acceptable energy storage capacity, with 36 and 46 rather than 1457 solar irradiance profiles, respectively.

Modelling Of Next Generation Standalone Solar Powered Micro Grid

French physicist “Edmund Becquerel” first discovered solar energy harnessed by the use of photovoltaic (PV) cells in 1839. This technology can be a single panel, or a string of PV panels, or a multitude of parallel strings of PV panels. Solar PV has no emissions and it is reliable and requires less maintenance. This project work is to model a standalone solar powered micro grid with an intelligent controller for controlling a hydraulically operated Solar PV System, which helps in unfolding the PV panels at site to where, the standalone Solar PV Power plant is transported and placed for power generation. The materials used for manufacturing PV cells include amorphous silicon, polycrystalline silicon, cadmium telluride, microcrystalline silicon and copper indium selenide.