An adaptive Neuro-Fuzzy controller for maximum power point tracking of photovoltaic systems

© 2015 IEEE. This paper presents a high performance tracking method for maximum power generated by photovoltaic (PV) systems. Based on adaptive Neuro-Fuzzy inference systems (ANFIS), this method combines the learning abilities of artificial neural networks and the ability of fuzzy logic to handle imprecise data. It is able to handle non-linear and time varying problems hence making it suitable for accurate maximum power point tracking (MPPT) to ensure PV systems work effectively. The performance of the proposed method is compared to that of a fuzzy logic based MPPT algorithm to demonstrate its effectiveness

Biomass energy in Bangladesh: current status and prospects

Bangladesh has been experiencing several problems over the past few decades. These include over population, energy crisis and global warming, etc. Adequate amount of power generation in a sustainable way is an important issue for rapidly increasing population and economic development. Renewable energy can play an effective role to meet energy demand. Since it is an agrarian country, biomass is one of the potential renewable energy sources in Bangladesh. Agricultural crop residues, animal manure and municipal solid waste are the major sources of biomass energy in the country. This paper presents the scope, potential and technologies related to the use of biomass resources. The study also discusses the biomass projects undertaken by the government and non-government organizations, plans and strategies to promote biomass technologies in Bangladesh

Energy management based on a fuzzy controller of a photovoltaic/fuel cell/Li-ion battery/supercapacitor for unpredictable, fluctuating, high-dynamic three-phase AC load

Introduction. Nowadays, environmental pollution becomes an urgent issue that undoubtedly influences the health of humans and other creatures living in the world. The growth of hydrogen energy increased 97.3 % and was forecast to remain the world’s largest source of green energy. It can be seen that hydrogen is one of the essential elements in the energy structure as well as has great potential to be widely used in the 21st century. Purpose. This paper aims to propose an energy management strategy based a fuzzy logic control, which includes a hybrid renewable energy sources system dedicated to the power supply of a three-phase AC variable load (unpredictable high dynamic). Photovoltaic (PV), fuel cell (FC), Li-ion battery, and supercapacitor (SC) are the four sources that make up the renewable hybrid power system; all these sources are coupled in the DC-link bus. Unlike usual the SC was connected to the DC-link bus directly in this research work in order to ensure the dominant advantage which is a speedy response during load fast change and loads transient. Novelty. The power sources (PV/FC/Battery/SC) are coordinated based on their dynamics in order to keep the DC voltage around its reference. Among the main goals achieved by the fuzzy control strategy in this work are to reduce hydrogen consumption and increase battery lifetime. Methods. This is done by controlling the FC current and by state of charge (SOC) of the battery and SC. To verify the fuzzy control strategy, the simulation was carried out with the same system and compared with the management flowchart strategy. The results obtained confirmed that the hydrogen consumption decreased to 26.5 g and the SOC for the battery was around 62.2-65 and this proves the desired goal.Вступ. В даний час забруднення навколишнього середовища стає актуальною проблемою, яка, безперечно, впливає на здоров’я людини та інших істот, які живуть у світі. Зростання водневої енергетики збільшилося на 97,3 %, і прогнозувалося, що вона залишиться найбільшим у світі джерелом зеленої енергії. Видно, що водень є одним із найважливіших елементів у структурі енергетики, а також має великий потенціал для широкого використання у 21 столітті. Мета. У цій статті пропонується стратегія управління енергоспоживанням, заснована на нечіткому логічному управлінні, яка включає гібридну систему відновлюваних джерел енергії, призначену для живлення трифазного змінного навантаження змінного струму (непередбачувана висока динаміка). Фотоелектричні (PV), паливні елементи (FC), літій-іонні батареї та суперконденсатори (SC) – це чотири джерела, з яких складається відновлювана гібридна енергосистема; всі ці джерела підключені до шини постійного струму. На відміну від звичайних застосувань,ув цій дослідницькій роботі SC був підключений до шини постійного струму безпосередньо, щоб забезпечити домінуючу перевагу, що полягає в швидкому реагуванні при швидкій зміні навантаження та перехідних режимах навантаження. Новизна. Джерела живлення (PV/FC/батареї/SC) координуються на основі їхньої динаміки, щоб підтримувати напругу постійного струму біля свого еталонного значення. Серед основних цілей, досягнутих стратегією нечіткого управління у цій роботі, - зниження споживання водню та збільшення терміну служби батареї. Методи. Це робиться шляхом керування струмом FC та станом заряду (SOC) батареї та SC. Для перевірки стратегії нечіткого управління було проведено моделювання з тією самою системою та порівняння зі стратегією блок-схеми керування. Отримані результати підтвердили, що споживання водню знизилося до 26,5 г, а SOC для батареї становило близько 62,2-65, що доводить досягнення бажаної мети

Maximum power point tracking of partial shaded photovoltaic array using an evolutionary algorithm: a particle swarm optimization technique

 Partial shading is one of the unavoidable complications in the field of solar power generation. Although the most common approach in increasing a photovoltaic (PV) array’s efficiency has always been to introduce a bypass diode to the said array, this poses another problem in the form of multi-peaks curves whenever the modules are partially shaded. To further complicate matters, most conventional Maximum Power Point Tracking methods develop errors under certain circumstances (for example, they detect the local Maximum Power Point (MPP) instead of the global MPP) and reduce the efficiency of PV systems even further. Presently, much research has been undertaken to improve upon them. This study aims to employ an evolutionary algorithm technique, also known as particle swarm optimization, in MPP detection. VC 2014 Author(s)

Addendum: Abubakar, U.; Mekhilef, S.; Mokhlis, H.; Seyedmahmoudian, M.; Horan, B.; Stojcevski, A.; Bassi, H.; Rawa, M.J.H. Transient Faults in Wind Energy Conversion Systems: Analysis, Modelling Methodologies and Remedies. Energies 2018, 11, 2249

The authors would like to make the following addition to their paper [...

A finite element analysis on combined convection and conduction in a channel with a thick walled cavity

Purpose: The purpose of this paper is to examine the effects of thick wall parameters of a cavity on combined convection in a channel. In other words, conjugate heat transfer is solved. Design/methodology/approach: Galerkin weighted residual finite element method is used to solve the governing equations of mixed convection. Findings: The streamlines, isotherms, local and average Nusselt numbers are obtained and presented for different parameters. It is found heat transfer is an increasing function of dimensionless thermal conductivity ratio. Originality/value: The literature does not have mixed convection and conjugate heat transfer problem in a channel with thick walled cavity

Improved energy conversion performance of a novel design of concentrated photovoltaic system combined with thermoelectric generator with advance cooling system

Most of the incident solar energy on a PV panel is converted into waste heat. This consequently reduces the efficiency of PV system. Therefore, if certain portion of this waste heat can be utilized adding a thermoelectric generator (TEG) in the PV panel endowed by an efficient cooling system, the output performance of the system can be improved significantly. In this study, a new configuration of nanofluid-based PV/T-TEG hybrid system with cooling channel is proposed to convert certain portion of waste heat to electrical energy in order to improve the overall efficiency of hybrid system. Thus, the nanofluid acts as a coolant and absorbs the heat from the back side of TEG module raising its gradient of temperature, as well as the overall performance of the system. Through a numerical modelling approach, performance of the proposed innovative design has been investigated and compared with the conventional solar-harvesting technology systems. At the optimum value of solar concentration C, and maximum operating temperature of 35°C, the obtained results reveal that the electrical energy in NCPV/T-TEG configuration has been found higher by 10%, 47.7% and 49.5% against NCPV/T, CPV and CPV/TEG-HS systems, respectively. Overall, the proposed design of NCPV/T-TEG hybrid system has potential for further development in high-concentration solar systems. © 2018 Elsevier Lt

Investigating the cooling effect of a green roof in Melbourne

‘Green Our Rooftop’ aims to transform the rooftop of Treasury Place, a state government building in the inner city of Melbourne, into an intensive green roof under the notion of ‘Garden of Victorian Landscapes’. The concept behind the innovative green roof design is to break down perceived barriers to green roof retrofitting, limit the global temperature rise and help cool the city by advocating modifications in urban infrastructure (e.g. greening projects). This study quantified the cooling effect of the complex green rooftop of Treasury Place (which is characterised by a diverse range of plant types and topographies) by using ENVI-met to assess the air temperature and outdoor thermal comfort at rooftop and pedestrian levels. After verification through field measurements, the study also investigated how the adjustments in the green roof's design settings (e.g. leaf area index [LAI], plant height, soil moisture and additional green coverage) can further improve the green roof's thermal performance. The findings from our study indicate that the implemented green roof configuration effectively lowered the air temperatures at the roof level by 1.5 °C, simultaneously enhancing thermal comfort by 2.38 °C during hot summer days. This optimum performance was achieved when soil moisture levels were set at 0.6, plant height at 0.6, and LAI at 2.5. Our statistical analysis indicates that all these scenarios exhibited equivalent cooling benefits. Thus, a holistic approach optimizing LAI, plant height, soil moisture, and tree coverage combined is essential to maximise cooling impact when integrating green roofs into future developments in inner city areas

A new eight switch seven level boost active neutral point clamped (8S-7L-BaNPC) inverter

A new boost Active-Neutral-Clamped (ANPC) voltage boosting inverters are appealing for low dc-link voltage demand. Recent boost ANPC topology has demonstrated a 1.5 times voltage gain, but the number of switches has a higher number. This paper proposed an improved boost ANPC topology with 1.5 voltage gain using the least number of switches. Further, the number of conducting switches has been reduced remarkably which enhances the system efficiency. The seven-level (7L) output voltage levels are achieved using a floating capacitor with self-voltage balancing capability. The proposed topology has been analyzed and compared to the ANPC topologies proposed in recent years. For the validation of the theoretical aspect of the proposed topology, the experimental findings have been compiled in the paper.This work was supported by the Qatar University-Marubeni Concept to Prototype Development Research grant # [MCTP-CENG-2020-2] from the Qatar University and the publication charges is paid by the Qatar National Library, Doha, Qatar.Scopu