This paper provides a comprehensive review of the maximum power point tracking (MPPT) techniques applied to photovoltaic (PV) power system available until January, 2012. A good number of publications report on different MPPT techniques for a PV system together with implementation. But, confusion lies while selecting a MPPT as every technique has its own merits and demerits. Hence, a proper review of these techniques is essential. Unfortunately, very few attempts have been made in this regard, excepting two latest reviews on MPPT [Salas, 2006], [Esram and Chapman, 2007]. Since, MPPT is an essential part of a PV system, extensive research has been revealed in recent years in this field and many new techniques have been reported to the list since then. In this paper, a detailed description and then classification of the MPPT techniques have made based on features, such as number of control variables involved, types of control strategies employed, types of circuitry used suitably for PV system and practical/commercial applications. This paper is intended to serve as a convenient reference for future MPPT users in PV systems.

A Comparative Study on Maximum Power Point Tracking Techniques for Photovoltaic Power Systems

This paper presents a review of control strategies, stability analysis, and stabilization techniques for dc microgrids (MGs). Overall control is systematically classified into local and coordinated control levels according to respective functionalities in each level. As opposed to local control, which relies only on local measurements, some line of communication between units needs to be made available in order to achieve the coordinated control. Depending on the communication method, three basic coordinated control strategies can be distinguished, i.e., decentralized, centralized, and distributed control. Decentralized control can be regarded as an extension of the local control since it is also based exclusively on local measurements. In contrast, centralized and distributed control strategies rely on digital communication technologies. A number of approaches using these three coordinated control strategies to achieve various control objectives are reviewed in this paper. Moreover, properties of dc MG dynamics and stability are discussed. This paper illustrates that tightly regulated point-of-load converters tend to reduce the stability margins of the system since they introduce negative impedances, which can potentially oscillate with lightly damped power supply input filters. It is also demonstrated that how the stability of the whole system is defined by the relationship of the source and load impedances, referred to as the minor loop gain. Several prominent specifications for the minor loop gain are reviewed. Finally, a number of active stabilization techniques are presented.

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DC Microgrids—Part I: A Review of Control Strategies and Stabilization Techniques

This paper presents a maximum power point tracking (MPPT) design for a photovoltaic (PV) system using a grey wolf optimization (GWO) technique. The GWO is a new optimization method which overcomes the limitations such as lower tracking efficiency, steady-state oscillations, and transients as encountered in perturb and observe (P&O) and improved PSO (IPSO) techniques. The problem of tracking the global peak (GP) of a PV array under partial shading conditions (PSCs) is attempted employing the GWO-based MPPT technique. The proposed scheme is studied for a PV array under PSCs which exhibits multiple peaks and its tracking performance is compared with that of two MPPT algorithms, namely P&O-MPPT and IPSO-MPPT. The proposed GWO-MPPT algorithm is implemented on a PV system using MATLAB/SIMULINK. Furthermore, an experimental setup is developed to verify the efficacy of the proposed system. From the obtained simulation and experimental results, it is observed that the proposed MPPT algorithm outperforms both P&O and IPSO MPPTs.

A New MPPT Design Using Grey Wolf Optimization Technique for Photovoltaic System Under Partial Shading Conditions

An improved perturb and observe (P&O) maximum power point tracking (MPPT) algorithm for higher efficiency

Maximum Power Point Tracking (MPPT) methods are used in photovoltaic (PV) systems to continually maximize the PV array output power which generally depends on solar radiation and cell temperature. MPPT methods can be roughly classified into two categories: there are conventional methods, like the Perturbation and Observation (P&O) method and the Incremental Conductance (IncCond) method and advanced methods, such as, fuzzy logic (FL) based MPPT method. This paper presents a survey of these methods in order to analyze, simulate, and evaluate a PV power supply system under varying meteorological conditions. Simulation results, obtained using MATLAB/Simulink, show that static and dynamic performances of fuzzy MPPT controller are better than those of conventional techniques based controller.

A survey of the most used MPPT methods: Conventional and advanced algorithms applied for photovoltaic systems

This brief proposes a new maximum power point tracker (MPPT) for a stand-alone photovoltaic (PV) system using the concept of double integral sliding mode controller (DISMC). Performance of a sliding mode controller (SMC) is greatly influenced by the choice of the sliding surface. A double integral SMC uses double integral of tracking voltage error term in its sliding surface to eliminate steady-state error apart from providing robust control actions in face of system uncertainties. However, there is still difficulty of increased chattering and slow transient response in DISMC. In this brief, the objective is to exploit the merits of the DISMC for designing an MPPT for PV system whilst the disadvantages of chattering and slow transient response are alleviated by choosing a new sliding surface. The design of this new DISMC-MPPT system considers the uncertainties in weather conditions and variations in load. This MPPT has been implemented using a pulsewidth modulator controlled dc/dc converter to keep the switching frequency constant. Thus, designing the control and filter circuits becomes simpler. The effectiveness of the proposed DISMC has been validated using simulation and experimental results using a prototype PV control system setup.

Double Integral Sliding Mode MPPT Control of a Photovoltaic System

This paper presents a new parameter extraction method for photovoltaic (PV) modules exploiting Bacterial Foraging Optimization (BFO) technique. In a PV system, validation of the model of a PV module with correctly chosen parameters is essential. An efficient parameter extraction method is required to estimate the parameters of PV module. Although, a number of parameter extraction methods are available in literature but there is a need to explore parameter extraction methods that could extract globally optimized parameters in changing weather conditions. One of the recent evolutionary computing approaches called BFO exhibits global optimization performance. Therefore, we employ BFO for extraction of parameters of a PV module. The proposed BFO-based parameter extraction method has been tested for different types of PV modules at different test conditions. Analyzing both the simulation and experimental results obtained using BFO; it is found that the module parameters are more accurate compared to that of Newton–Raphson, particle swarm optimization, and enhanced simulated annealing methods.

Bacterial Foraging Optimization Approach to Parameter Extraction of a Photovoltaic Module

This paper proposes a Newton-Raphson based parameter extraction method based on experimental analysis for modeling of a PV panel. In this method, pre-knowledge of open-circuit voltage, short-circuit current, maximum power point voltage and current is not necessary. Hence, the proposed parameter extraction method and analysis described in this paper can be suitably employed to obtain the panel dynamics for a PV panel without any information of voltage, current or power rating. Together with the parameter extraction, I-V and P-V characteristics and maximum power point tracking analysis has also been conducted to the PV panel.

Raseswari Pradhan

Papers

A Comparative Study on Maximum Power Point Tracking Techniques for Photovoltaic Power Systems

Double Integral Sliding Mode MPPT Control of a Photovoltaic System

Bacterial Foraging Optimization Approach to Parameter Extraction of a Photovoltaic Module

Characteristics evaluation and parameter extraction of a solar array based on experimental analysis

Design and real-time implementation of a new auto-tuned adaptive MPPT control for a photovoltaic system