Novel maximum-power-point-tracking controller for photovoltaic energy conversion system[edit | edit source]
Yeong-Chan Kuo; Tsorng-Juu Liang; Jiann-Fuh Chen, "Novel maximum-power-point-tracking controller for photovoltaic energy conversion system," Industrial Electronics, IEEE Transactions on , vol.48, no.3, pp.594,601, Jun 2001 doi: 10.1109/41.925586
A novel maximum-power-point-tracking (MPPT) controller for a photovoltaic (PV) energy conversion system is presented. Using the slope of power versus voltage of a PV array, the proposed MPPT controller allows the conversion system to track the maximum power point very rapidly. As opposed to conventional two-stage designs, a single-stage configuration is implemented, resulting in size and weight reduction and increased efficiency. The proposed system acts as a solar generator on sunny days, in addition to working as an active power line conditioner on rainy days. Finally, computer simulations and experimental results demonstrate the superior performance of the proposed technique
Solar photovoltaic (PV) energy; latest developments in the building integrated and hybrid PV systems[edit | edit source]
A. Zahedi, Solar photovoltaic (PV) energy; latest developments in the building integrated and hybrid PV systems, Renewable Energy, Volume 31, Issue 5, April 2006, Pages 711-718, ISSN 0960-1481, http://dx.doi.org/10.1016/j.renene.2005.08.007.
Environmental concerns are growing and interest in environmental issues is increasing and the idea of generating electricity with less pollution is becoming more and more attractive. Unlike conventional generation systems, fuel of the solar photovoltaic energy is available at no cost. And solar photovoltaic energy systems generate electricity pollution-free and can easily be installed on the roof of residential as well as on the wall of commercial buildings as grid-connected PV application. In addition to grid-connected rooftop PV systems, solar photovoltaic energy offers a solution for supplying electricity to remote located communities and facilities, those not accessible by electricity companies.
The interest in solar photovoltaic energy is growing worldwide. Today, more than 3500MW of photovoltaic systems have been installed all over the world. Since 1970, the PV price has continuously dropped [8]. This price drop has encouraged worldwide application of small-scale residential PV systems. These recent developments have led researchers concerned with the environment to undertake extensive research projects for harnessing renewable energy sources including solar energy. The usage of solar photovoltaic as a source of energy is considered more seriously making future of this technology looks promising.
The objective of this contribution is to present the latest developments in the area of solar photovoltaic energy systems. A further objective of this contribution is to discuss the long-term prospect of the solar photovoltaic energy as a sustainable energy supply.
Evaluating the limits of solar photovoltaics (PV) in electric power systems utilizing energy storage and other enabling technologies[edit | edit source]
Paul Denholm, Robert M. Margolis, Evaluating the limits of solar photovoltaics (PV) in electric power systems utilizing energy storage and other enabling technologies, Energy Policy, Volume 35, Issue 9, September 2007, Pages 4424-4433, ISSN 0301-4215, http://dx.doi.org/10.1016/j.enpol.2007.03.004.
In this work, we evaluate technologies that will enable solar photovoltaics (PV) to overcome the limits of traditional electric power systems. We performed simulations of a large utility system using hourly solar insolation and load data and attempted to provide up to 50% of this system's energy from PV. We considered several methods to avoid the limits of unusable PV that result at high penetration due to the use of inflexible baseload generators. The enabling technologies considered in this work are increased system flexibility, load shifting via demand responsive appliances, and energy storage.
An investigation of mismatch losses in solar photovoltaic cell networks[edit | edit source]
N.D. Kaushika, Anil K. Rai, An investigation of mismatch losses in solar photovoltaic cell networks, Energy, Volume 32, Issue 5, May 2007, Pages 755-759, ISSN 0360-5442, http://dx.doi.org/10.1016/j.energy.2006.06.017.
Solar photovoltaic (PV) arrays in field conditions deliver lower power than the array rating. In this paper, the sensitivity of solar cell parameters in the variation of available power from the array is investigated. The parameters characteristic of aging and fresh cells used in prototype field systems have been used for computation of reduction in the available power. It is found that in series string the fractional power loss would increase from 2% to 12% with aging of solar cells. However, this fractional power loss may be reduced to 0.4–2.4% by an appropriate series-paralleling.
Effects of mismatch losses in photovoltaic arrays[edit | edit source]
Charles E. Chamberlin, Peter Lehman, James Zoellick, Gian Pauletto, Effects of mismatch losses in photovoltaic arrays, Solar Energy, Volume 54, Issue 3, March 1995, Pages 165-171, ISSN 0038-092X, http://dx.doi.org/10.1016/0038-092X(94)00120-3.
Experimental and modeling results on the effects of mismatch losses in photovoltaic arrays are presented. Field tests conducted on each of the 192 modules are used to describe the variation in the properties of production run photovoltaic modules. Module specific estimates of a five-parameter module model are obtained by nonlinear regression. Mathematical models of four-module parallel string and series block photovoltaic array performance based on the five-parameter module model are developed and used to evaluate the variation in maximum output power and mismatch loss of arrays with random module orderings. Module maximum output power averaged 14% below the nameplate rating and exhibited a coefficient of variation of 2.1%. Mismatch losses were very small, never exceeding 0.53%. No differences between parallel string and series block arrays in array maximum output power were observed.
Forecasting photovoltaic array power production subject to mismatch losses[edit | edit source]
D. Picault, B. Raison, S. Bacha, J. de la Casa, J. Aguilera, Forecasting photovoltaic array power production subject to mismatch losses, Solar Energy, Volume 84, Issue 7, July 2010, Pages 1301-1309, ISSN 0038-092X, http://dx.doi.org/10.1016/j.solener.2010.04.009.
The development of photovoltaic (PV) energy throughout the world this last decade has brought to light the presence of module mismatch losses in most PV applications. Such power losses, mainly occasioned by partial shading of arrays and differences in PV modules, can be reduced by changing module interconnections of a solar array. This paper presents a novel method to forecast existing PV array production in diverse environmental conditions. In this approach, field measurement data is used to identify module parameters once and for all. The proposed method simulates PV arrays with adaptable module interconnection schemes in order to reduce mismatch losses. The model has been validated by experimental results taken on a 2.2 kWp plant, with three different interconnection schemes, which show reliable power production forecast precision in both partially shaded and normal operating conditions. Field measurements show interest in using alternative plant configurations in PV systems for decreasing module mismatch losses.
How to Design and Build a Solar Battery Charger[edit | edit source]
http://web.archive.org/web/20190911094150/http://www.solarjourneyusa.com:80/installguidesmall.php
The goal of these lessons is to clearly explain how to size and build a solar battery charging system. Most PV systems are grid connected, but here we focus on small, stand-alone arrays that charge a battery using either a Maximum Power Point Tracker (MPPT) or a conventional (PWM) charge controller. It is the ideal way to learn about solar power and batteries. We include handy information about pricing, component suggestions and links to high price/quality vendors. If you follow all the lessons in this course, you will be able to build your own array for about $7-8 per Watt and use it to charge your mobile phone, iPods and run other electrical devices. As long as you're familiar with some basic terms like Volt (V), Amps (A) and Watts (W), this should be a piece of cake!
Residential photovoltaic energy storage system[edit | edit source]
Chiang, S.J.; Chang, K.T.; Yen, C.Y., "Residential photovoltaic energy storage system," Industrial Electronics, IEEE Transactions on , vol.45, no.3, pp.385,394, Jun 1998 doi: 10.1109/41.678996
This paper introduces a residential photovoltaic (PV) energy storage system, in which the PV power is controlled by a DC-DC power converter and transferred to a small battery energy storage system (BESS). For managing the power, a pattern of daily operation considering the load characteristic of the homeowner, the generation characteristic of the PV power, and the power-leveling demand of the electric utility is prescribed. The system looks up the pattern to select the operation mode, so that powers from the PV array, the batteries and the utility are utilized in a cost-effective manner. As for the control of the system, a novel control technique for the maximum power-point tracking (MPPT) of the PV array is proposed, in which the state-averaged model of the DC-DC power converter, including the dynamic model of the PV array, is derived. Accordingly, a high-performance discrete MPPT controller that tracks the maximum power point with zero-slope regulation and current-mode control is presented. With proposed arrangements on the control of the BESS and the current-to-power scaling factor setting, the DC-DC power converter is capable of combining with the BESS for performing the functions of power conditioning and active power filtering. An experimental 600 W system is implemented, and some simulation and experimental results are provided to demonstrate the effectiveness of the proposed system
The vanadium redox-battery: an efficient storage unit for photovoltaic systems[edit | edit source]
Ch Fabjan, J Garche, B Harrer, L Jörissen, C Kolbeck, F Philippi, G Tomazic, F Wagner, The vanadium redox-battery: an efficient storage unit for photovoltaic systems, Electrochimica Acta, Volume 47, Issue 5, 3 December 2001, Pages 825-831, ISSN 0013-4686, http://dx.doi.org/10.1016/S0013-4686(01)00763-0.
The 'all vanadium redox flow system' is a promising candidate for the storage of photovoltaic energy. The reversible cell voltage of 1.3–1.4 V in charged state is well established at various electrode materials in particular carbon based substrate. The kinetics and mechanism were studied for the V2+/V3+ and VO++/VO2+ (V4+/V5+) couples and a one-electron transfer identified as the rate-determining step at smooth surface. The use of activation layers (carbon cloth, felt, etc.) decisively reduced the polarization. Catalysts, which are required for an increase of the reaction rate and the elimination of undesired side reactions, e.g. Ru(O)2 improved the behavior of the positive electrode. The influence of the separator material on mass transfer phenomena (diffusion, migration) and the charge–discharge characteristics were investigated. The requirements to be met as stand alone batteries for the energy supply of users in combination with photovoltaic plants considering the solar irradiation conditions in south Portugal were discussed and the future development goals defined.
Possible use of vanadium redox-flow batteries for energy storage in small grids and stand-alone photovoltaic systems[edit | edit source]
Ludwig Joerissen, Juergen Garche, Ch. Fabjan, G. Tomazic, Possible use of vanadium redox-flow batteries for energy storage in small grids and stand-alone photovoltaic systems, Journal of Power Sources, Volume 127, Issues 1–2, 10 March 2004, Pages 98-104, ISSN 0378-7753, http://dx.doi.org/10.1016/j.jpowsour.2003.09.066.
The all-vanadium redox-flow battery is a promising candidate for load leveling and seasonal energy storage in small grids and stand-alone photovoltaic systems. The reversible cell voltage of 1.3 to 1.4 V in the charged state allows the use of inexpensive active and structural materials. In this work, studies on the performance of inexpensive active materials for use in vanadium redox-flow batteries are reported. Additionally, a cost analysis for a load leveling and a seasonal energy storage system is given based on a flow battery technology well established in Zn-flow batteries.
Energy storage systems—Characteristics and comparisons[edit | edit source]
H. Ibrahim, A. Ilinca, J. Perron, Energy storage systems—Characteristics and comparisons, Renewable and Sustainable Energy Reviews, Volume 12, Issue 5, June 2008, Pages 1221-1250, ISSN 1364-0321, http://dx.doi.org/10.1016/j.rser.2007.01.023.
Electricity generated from renewable sources, which has shown remarkable growth worldwide, can rarely provide immediate response to demand as these sources do not deliver a regular supply easily adjustable to consumption needs. Thus, the growth of this decentralized production means greater network load stability problems and requires energy storage, generally using lead batteries, as a potential solution. However, lead batteries cannot withstand high cycling rates, nor can they store large amounts of energy in a small volume. That is why other types of storage technologies are being developed and implemented. This has led to the emergence of storage as a crucial element in the management of energy from renewable sources, allowing energy to be released into the grid during peak hours when it is more valuable.
The work described in this paper highlights the need to store energy in order to strengthen power networks and maintain load levels. There are various types of storage methods, some of which are already in use, while others are still in development. We have taken a look at the main characteristics of the different electricity storage techniques and their field of application (permanent or portable, long- or short-term storage, maximum power required, etc.). These characteristics will serve to make comparisons in order to determine the most appropriate technique for each type of application.
Steady-state performance of a grid-connected rooftop hybrid wind-photovoltaic power system with battery storage[edit | edit source]
Giraud, F.; Salameh, Z.M., "Steady-state performance of a grid-connected rooftop hybrid wind-photovoltaic power system with battery storage," Energy Conversion, IEEE Transactions on , vol.16, no.1, pp.1,7, Mar 2001 doi: 10.1109/60.911395
This paper reports the performance of a 4-kW grid-connected residential wind-photovoltaic system (WPS) with battery storage located in Lowell, MA, USA. The system was originally designed to meet a typical New-England (TNE) load demand with a loss of power supply probability (LPSP) of one day in ten years as recommended by the Utility Company. The data used in the calculation was wind speed and irradiance of Login Airport Boston (LAB) obtained from the National Climate Center in North Carolina. The present performance study is based on two-year operation. (May 1996-Apr 1998) of the WPS. Unlike conventional generation, the wind and the sunrays are available at no cost and generate electricity pollution-free. Around noontime the WPS satisfies its load and provides additional energy to the storage or to the grid. On-site energy production is undoubtedly accompanied with minimization of environmental pollution, reduction of losses in power systems transmission and distribution equipment, and supports the utility in demand side management. This paper includes discussion on system reliability, power quality, loss of supply and effects of the randomness of the wind and the solar radiation on system design
Energy analysis of batteries in photovoltaic systems. Part I: Performance and energy requirements[edit | edit source]
Carl Johan Rydh, Björn A. Sandén, Energy analysis of batteries in photovoltaic systems. Part I: Performance and energy requirements, Energy Conversion and Management, Volume 46, Issues 11–12, July 2005, Pages 1957-1979, ISSN 0196-8904, http://dx.doi.org/10.1016/j.enconman.2004.10.003.
The technical performance and energy requirements for production and transportation of a stand alone photovoltaic (PV)-battery system at different operating conditions are presented. Eight battery technologies are evaluated: lithium-ion (Li-ion), sodium–sulphur (NaS), nickel–cadmium (NiCd), nickel–metal hydride (NiMH), lead–acid (PbA), vanadium-redox (VRB), zinc–bromine (ZnBr) and polysulfide-bromide (PSB). In the reference case, the energy requirements for production and transport of PV-battery systems that use the different battery technologies differ by up to a factor of three. Production and transport of batteries contribute 24–70% to the energy requirements, and the PV array contributes 26–68%. The contribution from other system components is less than 10%. The contribution of transport to energy requirements is 1–9% for transportation by truck, but may be up to 73% for air transportation. The energy requirement for battery production and transport is dominant for systems based on NiCd, NiMH and PbA batteries. The energy requirements for these systems are, therefore, sensitive to changes in battery service life and gravimetric energy density. For systems with batteries with relatively low energy requirement for production and transportation (Li-ion, NaS, VRB, ZnBr, PSB), the battery charge–discharge efficiency has a larger impact. In Part II, the data presented here are used to calculate energy payback times and overall battery efficiencies of the PV-battery systems.
Optimum photovoltaic array size for a hybrid wind/PV system[edit | edit source]
Borowy, B.S.; Salameh, Z.M., "Optimum photovoltaic array size for a hybrid wind/PV system," Energy Conversion, IEEE Transactions on , vol.9, no.3, pp.482,488, Sep 1994 doi: 10.1109/60.326466
A methodology for calculation of the optimum size of a PV array for a stand-alone hybrid wind/PV power system is developed. Long term data of wind speed and irradiance recorded for every hour of the day for 30 years were used. These data were used to calculate the probability density functions of the wind speed and the irradiance for each hour of a typical day in a month. The wind speed and irradiance probability density functions and manufacturer's specification on a wind turbine and a PV module were used to calculate the average power generated by the wind turbine and the PV module for each hour of a typical day in a month. The least square method is used to determine the best fit of the PV array and wind turbine to a given load. On the basis of the energy concept an algorithm was developed to find the optimum size of the PV array in the system
A battery management system for stand alone photovoltaic energy systems[edit | edit source]
Duryea, S.; Islam, S.; Lawrance, W., "A battery management system for stand alone photovoltaic energy systems," Industry Applications Conference, 1999. Thirty-Fourth IAS Annual Meeting. Conference Record of the 1999 IEEE , vol.4, no., pp.2649,2654 vol.4, 1999 doi: 10.1109/IAS.1999.799211
This paper outlines the development of a battery management system (BMS) for stand alone photovoltaic (PV) energy systems. The BMS calculates the state of charge (SOC) of a lead acid battery to determine the capacity over time. This enables intelligent control schemes to be implemented. A fully functioning prototype was constructed that involved both hardware and software design. Several tests were performed to evaluate the operation of the BMS. The effect of measurement errors on the SOC calculation were subsequently investigated
A stand-alone photovoltaic supercapacitor battery hybrid energy storage system[edit | edit source]
Glavin, M.E.; Chan, P.K.W.; Armstrong, S.; Hurley, W.G., "A stand-alone photovoltaic supercapacitor battery hybrid energy storage system," Power Electronics and Motion Control Conference, 2008. EPE-PEMC 2008. 13th , vol., no., pp.1688,1695, 1-3 Sept. 2008 doi: 10.1109/EPEPEMC.2008.4635510
Most of the stand-alone photovoltaic (PV) systems require an energy storage buffer to supply continuous energy to the load when there is inadequate solar irradiation. Typically, Valve Regulated Lead Acid (VRLA) batteries are utilized for this application. However, supplying a large burst of current, such as motor startup, from the battery degrades battery plates, resulting in destruction of the battery. An alternative way of supplying large bursts of current is to combine VRLA batteries and supercapacitors to form a hybrid storage system, where the battery can supply continuous energy and the supercapacitor can supply the instant power to the load. In this paper, the role of the supercapacitor in a PV energy control unit (ECU) is investigated by using Matlab/Simulink models. The ECU monitors and optimizes the power flow from the PV to the battery-supercapacitor hybrid and the load. Three different load conditions are studied, including a peak current load, pulsating current load and a constant current load. The simulation results show that the hybrid storage system can achieve higher specific power than the battery storage system.
Optimal capacity of the battery energy storage system in a power system[edit | edit source]
Tsung-Ying Lee; Nanming Chen, "Optimal capacity of the battery energy storage system in a power system," Energy Conversion, IEEE Transactions on , vol.8, no.4, pp.667,673, Dec 1993 doi: 10.1109/60.260979
This paper investigates the optimal capacity of a battery energy storage system in a power system. The Taiwan Power Company System is used as an example system to test this algorithm. Results show that the maximum economic benefit of battery energy storage in a power system can be achieved by this algorithm.
Influence of Battery/Ultracapacitor Energy-Storage Sizing on Battery Lifetime in a Fuel Cell Hybrid Electric Vehicle[edit | edit source]
Schaltz, E.; Khaligh, A.; Rasmussen, P.O., "Influence of Battery/Ultracapacitor Energy-Storage Sizing on Battery Lifetime in a Fuel Cell Hybrid Electric Vehicle," Vehicular Technology, IEEE Transactions on , vol.58, no.8, pp.3882,3891, Oct. 2009 doi: 10.1109/TVT.2009.2027909
Combining high-energy-density batteries and high-power-density ultracapacitors in fuel cell hybrid electric vehicles (FCHEVs) results in a high-performance, highly efficient, low-size, and light system. Often, the battery is rated with respect to its energy requirement to reduce its volume and mass. This does not prevent deep discharges of the battery, which are critical to the lifetime of the battery. In this paper, the ratings of the battery and ultracapacitors are investigated. Comparisons of the system volume, the system mass, and the lifetime of the battery due to the rating of the energy storage devices are presented. It is concluded that not only should the energy storage devices of a FCHEV be sized by their power and energy requirements, but the battery lifetime should also be considered. Two energy-management strategies, which sufficiently divide the load power between the fuel cell stack, the battery, and the ultracapacitors, are proposed. A charging strategy, which charges the energy-storage devices due to the conditions of the FCHEV, is also proposed. The analysis provides recommendations on the design of the battery and the ultracapacitor energy-storage systems for FCHEVs.
Microcomputer Control of a Residential Photovoltaic Power Conditioning System[edit | edit source]
Bose, B.K.; Szczesny, P.M.; Steigerwald, Robert L., "Microcomputer Control of a Residential Photovoltaic Power Conditioning System," Industry Applications, IEEE Transactions on , vol.IA-21, no.5, pp.1182,1191, Sept. 1985 doi: 10.1109/TIA.1985.349522
Microcomputer-based control of a residential photovoltaic power conditioning system is described. The microcomputer is responsible for array current feedback control, maximum power tracking control, array safe zone steering control, phase-locked reference wave synthesis, sequencing control, and some diagnostics. The control functions are implemented using Intel 8751 single-chip microcomputer-based hardware and software. The controller has been tested in the laboratory with the prototype power conditioner and shows excellent performance.
The Quality of Load Matching in a Direct-Coupling Photovoltaic System[edit | edit source]
Applebaum, J., "The Quality of Load Matching in a Direct-Coupling Photovoltaic System," Energy Conversion, IEEE Transactions on , vol.EC-2, no.4, pp.534,541, Dec. 1987 doi: 10.1109/TEC.1987.4765889
The quality of load matching in a photovoltaic system determines the quality of system performance and the degree of the solar cells utilization. In a matched system, the operation of the load-line is close to the maximum power-line of the solar cell (SC) generator. Some load-lines inherently exhibit a relatively good matching when they are directly connected to the SC generator; for others, the matching is rather poor, and therefore, requires the inclusion of a maximum-power-point-tracker (MPPT) in the system. This present study deals with the performance analysis of six common types of loads that are directly connected to the SC generator, and defines a factor that describes the quality of matching of the load to the solar cells. The results of the study indicate the compatibility of the different loads when powered by solar cells, and will assist the designer of the photovoltaic system in considering whether to include an MPPT. The quality of load matching is defined here as the ratio of the load input power to the SC generator maximum power as a function of the solar insolation, or as a function of the solar time. The six loads are: an ohmic load, a storage battery, an ohmic load and storage battery, a water electrolyzer, a power conditioner--constant power load, and a dc motor driving volumetric and centrifugal pumps.
Stand-alone photovoltaic energy storage system with maximum power point tracking[edit | edit source]
Pacheco, V.A.; Freitas, L.C.; Vieira, J.B.; Coelho, E.A.A.; Farias, V.J., "Stand-alone photovoltaic energy storage system with maximum power point tracking," Applied Power Electronics Conference and Exposition, 2003. APEC '03. Eighteenth Annual IEEE , vol.1, no., pp.97,102 vol.1, 9-13 Feb. 2003 doi: 10.1109/APEC.2003.1179182
This digests deals with the study of a stand-alone photovoltaic system, which is able to extract the maximum power from photovoltaic array for all solar intensity conditions and to provide output voltage regulation. The proposed system consists of a DC-DC converter in combination with battery energy storage in a simple structure. Operating principle and control strategy are described. Digital simulation is included, supporting the validity of the concept.
