The many different techniques for maximum power point tracking of photovoltaic (PV) arrays are discussed. The techniques are taken from the literature dating back to the earliest methods. It is shown that at least 19 distinct methods have been introduced in the literature, with many variations on implementation. This paper should serve as a convenient reference for future work in PV power generation.

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Comparison of Photovoltaic Array Maximum Power Point Tracking Techniques

The photovoltaic (PV) system is one of the renewable energies that attract the attention of researchers in the recent decades. The PV generators exhibit nonlinear I–V and P–V characteristics. The maximum power produced varies with both irradiance and temperature. Since the conversion efficiency of PV arrays is very low, it requires maximum power point tracking (MPPT) control techniques. The maximum power point tracking (MPPT) is the automatic control algorithm to adjust the power interfaces and achieve the greatest possible power harvest, during moment to moment variations of light level, shading, temperature, and photovoltaic module characteristics. The purpose of the MPPT is to adjust the solar operating voltage close to the MPP under changing atmospheric conditions. It has become an essential component to evaluate the design performance of PV power systems. This investigation aims to assess different MPPT techniques, provide background knowledge, implementation topology, grid interconnection of PV and solar microinverter requirements presented in the literature, doing depth comparisons between them with a brief discussion. The MPPT merits, demerits and classification, which can be used as a reference for future research related to optimizing the solar power generation, are also discussed. Conventional methods are easy to implement but they suffer from oscillations at MPP and tracking speed is less due to fixed perturb step. Intelligent methods are efficient; oscillations are lesser at MPP in steady state and tracked quickly in comparison to conventional methods.

MPPT techniques for photovoltaic applications

In this paper, the concept of power tracking for PV systems is highlighted and an overview on 40 old and recent Maximum Power Point Tracking (MPPT) methods, available in the literature, is presented and classified. These methods are mathematically modeled and presented in such a way the reader can select the most appropriate method for his own application. A comparative table is presented at the end of the paper to simplify the classification of the different methods.

General review and classification of different MPPT Techniques

A system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.

Distributed Power Harvesting Systems Using DC Power Sources

Unfilled gap of prolonged energy demand by conventional energy sources and consent of global warming as its vulnerable outcome provides a vent to search compatible option. Augmentation in use of solar energy reveled through last 3 decades portrays its heterogeneous rewards in the prevailing energy scenario. Nevertheless solar PV system arises as viable option in the critical power system era its low efficiency energy conversion attribute necessitates an efficient power conversion system. The nonlinearity of I–V (current–voltage) characteristic and its alteration for an assorted insolation and temperature values may enable the alteration in terminal voltage. This may deviates maximum power point due to which the available maximum power delivery to load can be differed. Literature of this field reiterated that the uniform insolation and partial shading condition demands undeniable need of maximum power point tracking. Nonetheless through investigation in this direction furnishes the availability of a bunch of such techniques; each of them posses its own pros and cones. This ubiquitous trait of available maximum power point tracking (MPPT) techniques unfolds the complexity in its precise selection. To diminish such complexity this paper offers a state of art of various MPPT technique and their comprehensive comparative analysis based on 110 standard research articles. The focus of this paper is to offer a better commencement and to furnish valued information for investigators of this field.

Maximum power point tracking (MPPT) techniques: Recapitulation in solar photovoltaic systems

This paper presents the adaptive algorithm to resolve the problem in the maximum power point tracking (MPPT) of solar cell battery charger and applies it in the design for MPPT system. Results of the research show that the adaptive algorithm has not only accelerated the calculating speed and strengthen the searching performances, but also has the high tracking precision.

Application of adaptive algorithm of solar cell battery charger

In this paper, a new MPPT system has been developed, consisting of a buck-type dc/dc converter, which is controlled by a micro-controller-based unit. Based on the nonlinear characteristics of photovoltaic (PV), these paper designs a VSS controller to realize the maximum power output of PV arrays and introduces the system fundamental. Comparing with other techniques used in the past, the use of the proposed MPPT control improves the PV system performance. And the results of simulation and experiment are present.

The application of slide technology in PV maximum power point tracking system

The invention discloses a maximal power tracing and catching photovoltaic controlled method with self-adaptive searching algorithm, which comprises the following steps: setting initial step-length; monitoring the voltage and the current of the i time solar battery array; evaluating the i time power; getting voltage change quantity delta Ui and power change delta Pi of the i time and the i-1 time; judging whether the delta Ui is 0; backing to sample if delta Ui=0; evaluating slope delta Pi/delta Ui of P-V curve if delta Uiiƒ0; judging whether delta Pi/delta Ui absolute value is not less than the setting accuracy E; un-changing dutycycle of buck circuit switching tube if |delta Pi/delta Vi| =E. This invention does not need device to test light intensity and temperature, which can decrease the cost of solar electric power generation system.

Maximum power tracking capture photovoltaic control method with self-adaptive search algorithm

ADRC technique is the development of nonlinear PID approach. Based on extended state observer, the control effect of nonlinear state error feedback (NLSEF) controller has shown good adaptability to noise and model uncertainty by compensation for them in the control loop. However, there are many effects of nonlinear uncertain factors and outer interference in renewable energy systems connected grid. In this paper, the ADRC is used and a new type nonlinear function is applied in extended state observer and nonlinear state error feedback (NLSEF) controller. Simulation shows that the system is effective with excellent robustness.

Miao Zhang

Papers

Application of adaptive algorithm of solar cell battery charger

The application of slide technology in PV maximum power point tracking system

Maximum power tracking capture photovoltaic control method with self-adaptive search algorithm

The control system of renewable energy connected grid based on the ADRC technology