In recent decades, Photovoltaic (PV) energy has made significant progress towards meeting the continuously increasing world energy demand. Besides that, the issue of conventional fossil fuels depletion as well as environmental pollution both contribute to the growth of PV technology. However, the deployment and implementation of photovoltaic systems remain as a great challenge, since the PV material cost is still very high. The low PV module conversion efficiency is another factor that restricts the wide usage of PV systems, therefore a power converter embedded with the capability of maximum power point tracking (MPPT) integrated with PV systems is essential to further the technology. This paper provides a comprehensive review of the available MPPT techniques, both the uniform insolation and partial shaded conditions. In order to appreciate the knowledge of MPPT concepts, several types of PV cell equivalent models are explained too. Conventional MPPT techniques have proven the ability to track the maximum power point (MPP) under uniform solar irradiance. However, under rapidly changing environments and partially shaded conditions, conventional techniques have failed to track the true MPP. For this reason, stochastic based methods and artificial intelligence have been developed with the ability to seek the true MPP under multiple peaks with good convergence speed. This paper analyses and compares both conventional and stochastic MPPT techniques based on the true MPP tracking capability, design complexity, cost consideration, sensitivity to environmental change and convergence speed. Comparatively, the stochastic algorithms and artificial intelligence show excellent tracking performance. The research on MPPT techniques is ongoing towards achieving a better performance in terms of the ease of implementation, low system cost and better tracking efficiency.

A comprehensive review of maximum power point tracking algorithms for photovoltaic systems

Solar photovoltaic technology is one of the most important resources of renewable energy. However, the current solar photovoltaic systems have significant drawbacks, such as high costs compared to fossil fuel energy resources, low efficiency, and intermittency. Capturing maximum energy from the sun by using photovoltaic systems is challenging. Several factors that affect the energy output of such systems include the photovoltaic material, geographical location of solar irradiances, ambient temperature and weather, angle of sun incidence, and orientation of the panel. This study reviews the principles and mechanisms of photovoltaic tracking systems to determine the best panel orientation. The tracking techniques, efficiency, performance, advantages, and disadvantages of simple tracking systems are compared with those of state-of-the-art tracking systems. Diverse types of solar tracking systems based on their technologies and driving methods will be presented and categorized.The future trends of tracking systems are also highlighted.

Advances in solar photovoltaic tracking systems: A review

Fuzzy-PSO controller design for maximum power point tracking in photovoltaic system

Maximum power point tracking (MPPT) is one of the key functions of the solar power management system in solar energy deployment. This paper investigates the design of fuzzy-logic-based solar power MPPT algorithms using different fuzzy input variables. Six fuzzy MPPT algorithms, based on different input variables, were considered in this study, namely (i) slope (of solar power-versus-solar voltage) and changes of the slope; (ii) slope and variation of the power; (iii) variation of power and variation of voltage; (iv) variation of power and variation of current; (v) sum of conductance and increment of the conductance; and (vi) sum of angles of arctangent of the conductance and arctangent of increment of the conductance. Algorithms (i)–(iv) have two input variables each while algorithms (v) and (vi) use a single input variable. The fuzzy logic MPPT function is deployed using a buck-boost power converter. This paper presents the details of the determinations, considerations of the fuzzy rules, as well as advantages and disadvantages of each MPPT algorithm based upon photovoltaic (PV) cell properties. The range of the input variable of Algorithm (vi) is finite and the maximum power point condition is well defined in steady condition and, therefore, it can be used for multipurpose controller design. Computer simulations are conducted to verify the design.

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A Study on the Fuzzy-Logic-Based Solar Power MPPT Algorithms Using Different Fuzzy Input Variables

As an important part of power system, power transformer plays an irreplaceable role in the process of power transmission. Diagnosis of transformer’s failure is of significance to maintain its safe and stable operation. Frequency response analysis (FRA) has been widely accepted as an effective tool for winding deformation fault diagnosis, which is one of the common failures for power transformers. However, there is no standard and reliable code for FRA interpretation as so far. In this paper, support vector machine (SVM) is combined with FRA to diagnose transformer faults. Furthermore, advanced optimization algorithms are also applied to improve the performance of models. A series of winding fault emulating experiments were carried out on an actual model transformer, the key features are extracted from measured FRA data, and the diagnostic model is trained and obtained, to arrive at an outcome for classifying the fault types and degrees of winding deformation faults with satisfactory accuracy. The diagnostic results indicate that this method has potential to be an intelligent, standardized, accurate and powerful tool.

/pdf/classifying-transformer-winding-deformation-fault-types-and-2zct3pnuh7.pdf

Classifying Transformer Winding Deformation Fault Types and Degrees Using FRA Based on Support Vector Machine

Renewable energy sources have a great concern nowa-days to overcome the conventional energy source problem. The solar energy is one of the renewable energy that is implemented in different scale. The Photovoltaic (PV) cell is used to convert solar energy into electrical energy. The PV has nonlinear characteristics between its current and voltage. In addition, the PV power is highly sensitive to the atmospheric conditions, in particular temperature and solar radiation. This makes the PV has different equilibrium points. Therefore, selecting equilibrium points that extract the maximum allowable power of the PV is mandatory in order to enhance the PV system efficiency and robustness [1]. The controller that can select the optimal operating point is defined as the Maximum Power Point Tracking (MPPT). MPPT is addressed by different techniques scattered in literatures. This paper proposes a modified Fuzzy algorithm for MPPT of the PV system in order to enhance its performance, in transient and steady state, and robustness and accelerate the recovery time due to a sudden change in the connected load. A comparison between the proposed technique and conventional techniques is illustrated.

/pdf/maximum-power-point-tracking-using-fuzzy-logic-control-for-59681itw7k.pdf

Maximum Power Point Tracking using Fuzzy Logic Control for Photovoltaic Systems

Comparative study of lighting quality and power quality for LED and HPS luminaires in a roadway lighting system

This paper proposes the study and analysis of harmonics, energy consumption and power quality of light emitting diode (LED) lamps equipped in building lighting systems. LED lamps with external (LED MR16) and internal (LED light bulb) drivers are investigated using an experimental setup to compare the results. The power quality of both LED lamps is studied by using a power quality meter to measure the generated harmonic currents from various case studies. The case study is divided into four major cases: one LED lamp is turned on with one driver, two LED lamps are turned on using the two drivers, eight LED lamps are turned on with one driver, and eight LED lamps are turned on with the eight drivers. As harmonics are related to total power factor (PF), which affects the energy savings of the building, hence, a filtering circuit to reduce harmonic current has been designed and implemented to improve power quality and/or power factor of the system. The different cases of harmonic filter insertion at the input of an LED lamp’s driver are discussed and then compared with a lighting standard to show the effectiveness of the passive filtering technique used in the studied system. In addition, the obtained result can be applied to both newly built and retrofitted buildings that aim to use LED technology to increase energy efficiency and decrease energy costs, and could be a helpful guide for end-users and manufacturers in addressing and developing LED issues.

https://www.mdpi.com/1996-1073/11/11/3169/pdf

Harmonics and Reduction of Energy Consumption in Lighting Systems by Using LED Lamps

This study investigates the use of an alternative energy source in the production of electric energy to meet the increasing energy requirements, encourage the use of clean energy, and thus reduce the effects of global warming. The alternative energy source used is a mechanical energy by piezoelectric material, which can convert mechanical energy into electrical energy, that can convert mechanical energy from pressure forces and vibrations during activities such as walking and traveling into electrical energy. Herein, a pilot device is designed, involving the modification of a bicycle into a stationary exercise bike with a piezoelectric generator, to study energy conversion and storage generated from using the bike. Secondly, the piezoelectric energy harvesting system is used on bicycles as a micro-mobility, light electric utility vehicle with smart operation, providing a novel approach to smart city design. The results show that the energy harvested from the piezoelectric devices can be stored in a 3200 mAh, 5 V battery and power sensors on the bicycle. Moreover, 13.6 mW power can be generated at regular cycling speed, outputting 11.5 V and 1.2 mA. Therefore, the piezoelectric energy harvesting system has sufficient potential for application as a renewable energy source that can be used with low power equipment.

https://www.mdpi.com/2071-1050/12/7/2933/pdf

Development of Micro-Mobility Based on Piezoelectric Energy Harvesting for Smart City Applications

Photovoltaic (PV) energy has been widely interested today because it is clean and endless energy without causing pollution. To produce electricity from solar energy, it would be required an inverter to convert the direct current into alternating current. The inverter is the cause of problems that affect the stability of the power system because it is a switching device served to adjust the frequency of the AC power as needed. At the same time, it can cause harmonics which result in waveform distortion and affect electronic devices that receive power. Then, it could make electronic device malfunction. This paper studies the characteristics of harmonics on grid, PV system, and load. The result shows that most grid's harmonics are affected from PV system and load when the inverter power up to almost the rated power, meanwhile, percentages of harmonics are reduced and harmonics of load depend on the type of load. Next, comparing harmonics on three sides, and found that harmonics of PV system hardly affect to load and harmonics of grid are more affected from load than PV system.

Chaiyan Jettanasen

Papers

Maximum Power Point Tracking using Fuzzy Logic Control for Photovoltaic Systems

Comparative study of lighting quality and power quality for LED and HPS luminaires in a roadway lighting system

Harmonics and Reduction of Energy Consumption in Lighting Systems by Using LED Lamps

Development of Micro-Mobility Based on Piezoelectric Energy Harvesting for Smart City Applications

Power quality analysis of grid connected solar power inverter