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

Review of the maximum power point tracking algorithms for stand-alone photovoltaic systems

Current-voltage and power-voltage characteristics of large photovoltaic (PV) arrays under partially shaded conditions are characterized by multiple steps and peaks. This makes the tracking of the actual maximum power point (MPP) [global peak (GP)] a difficult task. In addition, most of the existing schemes are unable to extract maximum power from the PV array under these conditions. This paper proposes a novel algorithm to track the global power peak under partially shaded conditions. The formulation of the algorithm is based on several critical observations made out of an extensive study of the PV characteristics and the behavior of the global and local peaks under partially shaded conditions. The proposed algorithm works in conjunction with a DC-DC converter to track the GP. In order to accelerate the tracking speed, a feedforward control scheme for operating the DC-DC converter is also proposed, which uses the reference voltage information from the tracking algorithm to shift the operation toward the MPP. The tracking time with this controller is about one-tenth as compared to a conventional controller. All the observations and conclusions, including simulation and experimental results, are presented.

Maximum Power Point Tracking Scheme for PV Systems Operating Under Partially Shaded Conditions

This paper presents simulation and hardware implementation of incremental conductance (IncCond) maximum power point tracking (MPPT) used in solar array power systems with direct control method. The main difference of the proposed system to existing MPPT systems includes elimination of the proportional-integral control loop and investigation of the effect of simplifying the control circuit. Contributions are made in several aspects of the whole system, including converter design, system simulation, controller programming, and experimental setup. The resultant system is capable of tracking MPPs accurately and rapidly without steady-state oscillation, and also, its dynamic performance is satisfactory. The IncCond algorithm is used to track MPPs because it performs precise control under rapidly changing atmospheric conditions. MATLAB and Simulink were employed for simulation studies, and Code Composer Studio v3.1 was used to program a TMS320F2812 digital signal processor. The proposed system was developed and tested successfully on a photovoltaic solar panel in the laboratory. Experimental results indicate the feasibility and improved functionality of the system.

Simulation and Hardware Implementation of Incremental Conductance MPPT With Direct Control Method Using Cuk Converter

Artificial intelligence techniques for photovoltaic applications: A review

In grid-connected photovoltaic systems, a key consideration in the design and operation of inverters is how to achieve high efficiency with power output for different power configurations. The requirements for inverter connection include: maximum power point, high efficiency, control power injected into the grid, and low total harmonic distortion of the currents injected into the grid. Consequently, the performance of the inverters connected to the grid depends largely on the control strategy applied. This paper gives an overview of power inverter topologies and control structures for grid connected photovoltaic systems. In the first section, various configurations for grid connected photovoltaic systems and power inverter topologies are described. The following sections report, investigate and present control structures for single phase and three phase inverters. Some solutions to control the power injected into the grid and functional structures of each configuration are proposed.

Overview of power inverter topologies and control structures for grid connected photovoltaic systems

Most of single-stage power factor correction (PFC) ac-dc converters usually present a high voltage swing on the storage capacitor. That means, high size and cost of the storage capacitor is obtained. The Series Inductance Interval (SII) PFC converters allow reducing cost and size of the storage capacitor since the capacitor voltage is lower than the output voltage and, therefore, the voltage swing is significantly reduced. In this paper, the novel single-stage SII-B-2D PFC converter is presented. In addition, this topology provides input current harmonics under EN61000-3-2 Class D limits and advantageous component count

New Power Factor Correction AC-DC Converter With Reduced Storage Capacitor Voltage

An analysis has been made of the most important electrical parameters related to photovoltaic grid-connected inverters below 10 kW. To achieve this, a compilation of up to 50 manufacturers, various brands and up to 500 different models has been prepared and updated to February 2008. Datasheet and manuals have been compiled, noting down their electrical output and input characteristics. Different and important aspects with respect to performance of some PV grid-installation have been analyzed: the number of different models for values of power; topology option; operational DC parameters range (such as nominal power, maximum power, nominal current, voltage), operational AC parameter range (such as nominal power, maximum power, nominal current, voltage), inverter conversion efficiency vs nominal power and normalized inverter size and weight.

Overview of the state of technique for PV inverters used in low voltage grid-connected PV systems: Inverters below 10 kW

The fast response double buck (FRDB) dc-dc converter was presented like a low output voltage dc-dc converter with fast transient response, in order to feed devices such as microprocessors and digital signal processors (DSPs). The topology of the FRDB is composed of two buck converters connected in parallel, each one of them with different features and aims, and controlled by means of the novel linear-non-linear (LnL) control. In this paper, the topology, the control strategy and the operation principle are shown. Finally, experimental results in different prototypes are presented to show both, the transient response and the recovery time when these prototypes are subjected to load current steps, and the influence of the output filter on these parameters.

V. Salas

Papers

Review of the maximum power point tracking algorithms for stand-alone photovoltaic systems

Overview of power inverter topologies and control structures for grid connected photovoltaic systems

New Power Factor Correction AC-DC Converter With Reduced Storage Capacitor Voltage

Overview of the state of technique for PV inverters used in low voltage grid-connected PV systems: Inverters below 10 kW

The fast response double buck DC-DC converter (FRDB): operation and output filter influence