Renewable and Sustainable Energy Reviews (original) (raw)
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Influence of power converters on PV maximum power point tracking efficiency
2012 10th IEEE/IAS International Conference on Industry Applications, 2012
Photovoltaic maximum power point tracker (MPPT) systems are commonly employed to maximize the photovoltaic output power, since it is strongly affected in accordance to the incident solar radiation, surface temperature and load-type changes. Basically, a MPPT system consists on a dc-dc converter (hardware) controlled by a tracking algorithm (software) and the combination of both, hardware and software, defines the tracking efficiency. This paper shows that even when the most accurate algorithm is employed, the maximum power point cannot be found, since its imposition as operation point depends on the dc-dc converter static feature and the load-type connected to the system output. For validating the concept, the main dc-dc converters, i.e., Boost, Buck-Boost, Cuk, SEPIC and Zeta are analyzed considering two load-types: resistive voltage regulated dc bus. Simulation and experimental results are included for validating the theoretical analysis. I.
International journal of engineering research and technology, 2018
With the increasing in the energy demand conservation and utilization of energy are very essential. Hence Solar charge controller helps in increasing the efficiency of the solar power transferred to the battery. Photovoltaic modules show nonlinear output characteristics because of different system losses. Maximum power point tracking (MPPT) is an intelligent technique for reducing these losses by driving the system at its maximum operating point. DC/DC converter is an essential part of a MPPT controlled photovoltaic (PV) system which functions as an interface between PV system and the load. These Converters are mostly Dc Choppers which converts fixed Dc voltage to a variable Dc source. These Regulators are used in case of Solar Charge Controllers to increase or decrease the PV panel voltage to as that required by Battery. The DC voltage from the PV panel varies with the light intensity which depends on time of day and temperature. Similarly, on the Battery side the voltage varies depending on the load connections. Thus, for optimal charging of battery it is important that the voltage of the PV panel and the current matches the battery charging state at any instant. There are various types of Dc-Dc Converter of which Buck Boost Converter is taken into consideration. In this project work we propose an efficient photovoltaic system which will be designed, developed and the results will be validated in real time.
A Review on PV Systems with DC-DC Converter
The evaluation of power electronics has emerged since last few decades ago. The advancement in the power engineering has made many advantages as per cost, performance and size point of view. In recent years, the power electronics is used in many aspects of commercial, utility, military, transportation, aerospace, etc. A part of power electronics is DC-DC converter, and it has applicability in computers, spacecraft units, laptops, telecommunications and motor drives. The photovoltaic based energy generation is the modern way of generating the energy and is adopted all over the world. But the efficiency in power generation by the photovoltaic system varies with the climatic condition. To achieve better efficiency, DC-DC converter can be used. The technique called maximum power point tracking (MPPT) helps in efficiency optimization. This paper presents the survey over the existing energy optimization techniques; further efficiency optimization for future study is mentioned.
— This research work addresses a comparative examination of the two basic non-isolated DC-DC converters that could be interfaced effectively for maximum power point tracking (MPPT) in photovoltaic (PV) systems via tracking algorithm of controlling the duty ratio of these converters. Examination of two famous DC-DC convertor topologies i.e. buck, and buck-boost converters has been performed here to scrutinize the behavior of converter behavior relating to changing atmospheric attributes, sequentially the deviation in the duty ratio (due to MPPT), and tracking efficiency. With the variant in the atmospheric conditions, the working value of resistance at the maximum power point (Rmpp) varies. In order to efficiently operate the system at the maximum power point, the MPPT algorithm must make the system work near to the value of Rmpp for the intermittent atmospheric pattern of varying insolation and temperature. The effectiveness of the MPPT algorithm can be scaled by this very obligation. The simulation study verifies that, although buck, and buck-boost converters are implemented as power converters for MPPT control, they are don't equally efficient. The consequence of diverse loads having values different to Rmpp on converter-side output is analyzed for the two important topologies, and it is inferred that the buck-boost converter topology most efficiently tracks the maximum power point (MPP) in case of varying temperature, insolation, and loading effect.
2014 17th International Conference on Computer and Information Technology (ICCIT), 2014
ABSTRACT Photovoltaic modules show nonlinear output characteristics because of which different system loss occurs. Maximum power point tracking (MPPT) is an intelligent technique for reducing these losses by driving the system at its optimal operating point. In this paper two well established MPPT techniques: Perturb and Observe (P&O) method and Incremental conductance (INC) method is explained and verified with simulated results. Due to some drawbacks in P&O method, a comprehensive optimized photovoltaic system is designed implementing the INC method in Matlab/Simulink. DC/DC converter is an essential part of a MPPT controlled photovoltaic (PV) system which functions as an interface between PV system and load. There are many converter topologies whose are implemented according to their required applications. A detailed comparative study among buck, boost and buck-boost converters is presented here. Our study shows that among these three converters buck-boost delivers the maximum power to the load. Finally an optimized PV system implementing INC method interfaced with buck-boost converter is designed and simulated which is robust and compatible to all other techniques.
Cogent Engineering
This paper deals with the selection of dc-dc converter and control variable required to track the maximum power of photovoltaic (PV) array, to optimize the utilization of solar power. To reduce the maintenance cost and to simplify the model, the battery has not been used in the proposed PV system mainly used for cooking and heating applications. Since the battery has not been used, selection of dc-dc converter is an important consideration of the PV system in standalone applications. In the proposed system converter is selected based on maximum power transfer theorem which is dependent on load resistance. Different load resistance is considered for maximum power point tracking (MPPT) with different converter topologies, and it has been observed that buck-boost converter is suitable for any load resistance connected in the PV system. An effort has been taken to suitably choosing the control variable which is the output signal of the maximum power point (MPP) tracker. Control variable which is dependent on inputs of MPP tracker is decided based on the stability of the system. Two MPP trackers are designed based on neural-network (NN) controller and perturb and observe (P&O) algorithm. The tracking capabilities of
Survey on Maximum Power Point Tracking ( MPPT ) Technique for Photovoltaic ( PV ) System
2013
Photovoltaic (PV) energy is the most important energy resource since it is clean, pollution free, and inexhaustible. Due to rapid growth in the semiconductor and power electronics techniques, PV energy is of increasing interest in electrical power applications. It is important to operate PV energy conversion systems near the maximum power point to increase the output efficiency of PV arrays. A MPPT plays a very vital role for extracting the maximum power from the solar PV module and transferring that power to the load. In this paper a survey of recent Maximum Power Point Tracking (MPPT) Technique for Photovoltaic (PV) System is presented. A comparative study included in this paper with focusing on different MPPT technique, research advantages and drawbacks are provided as well. These techniques vary in many aspects as simplicity, digital or analogical implementation, sensor required, convergence speed, range of effectiveness, implementation hardware, popularity, cost and in other as...
Simulated Study on Nonisolated DC-DC Converters for MPP Tracking for Photovoltaic Power Systems
his paper discusses a comparative investigation of the three basic nonisolated DC-DC converters used as interfaces for maximum power point tracking (MPPT) in photovoltaic (PV) generators using the direct duty ratio control tracking algorithm. Analysis of buck, boost, and buck-boost converters is undertaken to study the behavior of converter performance with respect to changing atmospheric conditions, in-turn duty ratio variation (as a result of MPPT), and tracking efficiency. As atmospheric conditions change, the operating value of resistance at the maximum power point (Rmpp) changes. To effectively drive the system at the maximum power yield point, the MPPT algorithm has to drive the system operation point close to the value of Rmppfor the varying atmospheric profile of change in insolation and temperature. The efficiency of the MPPT algorithm lies in meeting this very requirement. The simulation study shows that, although buck, boost, and buck-boost converters are used as power converters in MPPT applications, not all converters perform with high efficiency. The effect of different resistive loads that have values other thanRmppon converter-side output is considered for the three topologies, and it is observed that the buck-boost converter is the only one that is able to track the maximum power point (MPP) under variations in insolation, temperature, and loading effect with the highest tracking efficiency
Performance enhancement of solar photovoltaic system using novel Maximum Power Point Tracking
The electrical power supplied by the photovoltaic (PV) array depends on insolation, temperature and load. On the other hand, the actual power produced by the PV array is not fully transferred to the load. Therefore, it is necessary to extract maximum power from PV array. Maximum Power Point Tracking (MPPT) is a power electronic system that extracts maximum power from PV system. MPPT varies the electrical operating point of the PV modules and enables them to deliver maximum available power. In this work, a new MPPT algorithm is designed that uses open circuit voltage and short circuit current, sampled from a reference PV Panel. Using these measurements the maximum power is been tracked from main panel without breaking the power transferred to load. A buck boost converter was used to match impedance between source and load to facilitate maximum power transfer. The proposed algorithm was checked for its performance in local environmental condition.