International Journal of Energy Technology and Policy (17 papers in press)
Italian short term load forecasting: different aggregation strategies
by Elisa Raspanti, Andrea Marziali
Abstract: This paper deals with one-day-\r\nahead forecasting of Italian electricity demand. The problem is\r\naddressed through machine learning techniques, nine base models (Ridge\r\nRegression, LASSO, Elastic Net, Support Vector Machine, Gaussian Process,\r\nk-Nearest Neighbour, Random Forest, Artificial Neural Network and\r\nTorus Model) and five aggregation models based on base model predictions\r\nwhose errors are automatically corrected by a SARIMA model. In\r\naddition to the aggregation strategy given by the five ensemble models, we\r\nanalyse also the time and spatial-time aggregations. After\r\nthe aggregation at an Italian daily level for the hourly and zonal-hourly\r\nforecasts, the comparison between these results and the initial daily base\r\nresults are analysed, in order to evaluate the three different aggregation\r\nstrategies. Dimension reduction by the PCA is also pursued in order to\r\nreduce the computation times and investigate the possible risk of overfitting.\r\n
Keywords: electricity demand; time series forecasting; statistical learning; neural\r\nnetworks; SARIMA; PCA.
Thermal analysis of LiFePo4 batteries during rapid charge with evaporative cooling system
by Md. Sazib Mollik, Mohd Mahbubur Rashid, MOHAMMED ATAUR RAHMAN
Abstract: The development of rapid charging mechanism for LiFePo_4 battery is one of the key concerns for electric vehicles. The main drawbacks of LiFePo_4 battery charging are overcharge, overcurrent, and high temperature which affects longevity, efficiency, and battery life cycle. Battery internal temperature increases because of ambient temperature and charging current (C-rate). C-rate is very crucial for battery charging system as the battery cell temperature highly depends on C-rate. In this paper, the effect of the internal temperature of the battery has been investigated during the rapid charging process. Firstly, the CC-CV charging method is applied for rapid charging to analyze the internal temperature. Then, this study develops a battery charging method with a thermal management system to enhance the battery charging performances by maintaining the lowest level of raised temperature. For the cooling system, Tetrafluoroethane (R-134a) is applied which is very rarely found in previous literatures. Experimental results have shown that the Refrigerant-134a based cooling system is capable to maintain battery temperature within the range of 20
Keywords: LiFePo_4 battery; rapid charging; CC-CV; SOC; temperature effect; thermal management system
?LiFePo?_4 battery; rapid charging; CC-CV; SOC; temperature effect; thermal management system.
Study on the role of transmission lines in network strengthening and influencing the power system inter-area modal characteristics
by Sirin Dutta Chowdhury
Abstract: Inter-area modes having inherent poor damping pose serious threats to the power system stability. These modes restrict the power transfer capacity of the transmission lines and hence need to be stabilised. In this paper, a simple and practicable method based on the modal analysis technique and the transmission system augmentation approach has been demonstrated which strengthens the power system network by damping its oscillatory modes. This technique also gives a fair idea regarding the optimal locations for different controllers' placement. A novel index namely 'mode contribution factor' has been introduced which quantifies the impact of the oscillatory modes on the synchronous machines. This paper also demonstrates the application of cut-set stability criterion to the improvement of the system damping. The proposed method has been validated using IEEE 16-machine 68 bus and IEEE 10-machine 39 bus test systems. The results have been compared to several published works and found to be in line with them.
Keywords: transmission lines; network strengthening; inter area oscillatory modes; modal analysis; system augmentation; optimal location; controller placement; mode shapes; damping improvement; cut-set stability criterion.
Flower pollination-based optimal placement of distributed generation units in distribution networks
by Yogambari Venkatesan, Aravindhababu Palanivelu
Abstract: The sharp increasing power demand and configuration changes in distribution networks (DNs) may operate the network more closely to voltage stability (VS) boundaries. Under critical operating conditions, the DN is not able to provide good voltage profile and may experience voltage collapse. Distributed generation (DG) has been popularly used in supplying real and reactive power in DNs. This paper builds the DG placement problem (DGPP) as a multi-objective optimisation problem with objectives of the lowering real power loss, enhancing the voltage profile, improving the VS and lowering the net operating cost; and suggests a solution scheme involving flower pollination-based optimisation (FPO) for optimally placing DGs in DNs. The FPO is a nature inspired algorithm of modelling the pollens of flowers as problem variables and the pollination process for optimising the (flowers) problem variables. The FPO in DGPP finds optimal nodes for DG placement in addition to sizing the DGs. It presents simulation results on standard IEEE DNs with a view of portraying the supremacy of the suggested strategy.
Keywords: distributed generation; flower pollination-based optimisation; FPO; distribution network; voltage stability.
Analysis of energy consumption and forecasting sectoral energy demand in Pakistan
by Zulfiqar Ali, Faheemullah Shaikh, Laveet Kumar, Sadam Hussain, Zubair Ahmed Memon
Abstract: The long-term forecasting of energy consumption has attained significant importance in fundamental research to provide sustainable solutions to the sectoral energy issues. An analysis of various factors that spur the overall and sectoral energy consumption has been modelled using logarithmic mean divisia index (LMDI) based on long-term energy alternatives planning (LEAP). The LMDI factors such as scale, structure and efficiency effects have been modelled in LEAP to forecast the overall and sectoral energy consumption. Various scenarios based on estimated LMDI factors have been modelled. It was observed that the scale and structure effects have generally caused an increase whereas the efficiency effect has caused a decrease in the overall and sectoral energy consumption. Furthermore, it was observed that the results reveal that the total energy consumption may reach 2,048,017.38 MTOE in 2050. Energy consumption in agriculture, industrial and services sector may reach 17,327.29 MTOE, 1,759,372.72 MTOE, 271,317.37 MTOE in 2050, respectively. From these findings, it is clear that the industrial sector consumes 86% of total energy. These results can help develop various policy guidelines for better management and operation of the energy sector in Pakistan.
Keywords: LMDI; LEAP; energy consumption; energy forecasting; Pakistan.
Investigations of electricity expansion environmental planning using LEAP model for sustainability
by K. Karunanithi, S. Ramesh, S.P. Raja, N.K. Rayaguru, S. Saravanan
Abstract: Electricity expansion planning is finding an optimal solution for the power system planning problem in which installation of new generation units satisfies both technical and financial constraints. Nowadays, renewable power generation plays an important role in power generation since it is pollution free and has zero fuel cost. In this paper, an attempt is made to design a future power system for Andhra Pradesh, an Indian state in which the electricity is generated mainly from non-renewable energy sources which increase greenhouse gases (GHGs) emission and hence global warming. Keeping in mind about pollution impacts, renewable energy sources like wind, solar, biomass are considered for Andhra Pradesh using long-range energy alternative planning system (LEAP) software. The various scenarios have been developed with LEAP and in all scenarios, the system installed capacity, 100-year global warming potential, social cost, production cost and total cost are investigated quantitatively.
Keywords: generation expansion planning; GEP; global warming potential; LEAP; renewable energy system; RES; social cost; net present value; NPV.
Experimental and numerical investigations on baffle assisted jet array impingement cooling with cross-flow
by Sabu Kurian, P.S. Tide, N. Biju
Abstract: Jet impingement is a powerful technique for enhancement of convective heat transfer. In this study, an attempt has been made to investigate the combined effect of jet impingement with cross-flow and insertion of baffles. The fluid flow and heat transfer characteristics of a 3 × 3 array of multiple impinging steady air jets together with cross-flow and baffles subjected to a constant heat flux are investigated numerically and experimentally. Numerical simulations employing SST k-ω turbulence model are utilised to investigate the effect of blow ratio and baffle clearance on flow dynamics and heat transfer characteristics. Experiments and numerical simulations were carried out with blow ratio ranging from 0.25 to 1.0 and baffle clearance of 1 mm, 2 mm and 3 mm. Insertion of baffles in the cross-flow path is found to augment heat transport. About three times increase in heat transfer rate was observed when baffles with 1 mm clearance and a blow ratio of 1.0 were employed. A correlation analysis based on statistical techniques was carried out to quantitatively express the relation between operating parameters such as blow ratio, baffle clearance, H/d ratio and Nusselt number.
Keywords: jet impingement; baffles; blow ratio.
Special Issue on: ICCSEMS-2020 Artificial Intelligence, Signal Processing and Mechatronics for Smart Energy Systems
A Decentralized Power Management strategy in Hybrid Energy Storage Supported Islanded Residential Sustainable DC Microgrid System
by Jaynendra Kumar, Anshul Agarwal, Nitin Singh
Abstract: Renewable energy transitions are essential for climate change mitigation and energy security. Microgrids are significant structures to integrate distributed renewable energy sources. DC microgrid has natural compatibility with the DC power generating sources like solar PV, storages like battery and supercapacitor, and modern DC loads like laptop batteries, cell phone batteries, and DC powered LED lights, etc. Power management has been a great concern for the developers and academic researchers in an islanded microgrid system to maximize the utilization of the intermittent renewable sources, provide quality and reliable power, and stabilize the DC microgrid system. A DC microgrid can be developed in household or community sizes. In this paper, A DC microgrid system has been proposed for residential purposes. The proposed DC microgrids components details and power management scheme has been discussed. The hybrid energy storage (Battery and supercapacitor) has been considered storage for the proposed DC microgrid. The incremental conductance (INC) algorithm has been implemented for the MPPT of the PV system as it is considered one of the most developed and accurate MPPT algorithm. A MATLAB/Simulink demonstration for the proposed system has been carried out. The simulations have been performed for various cases to analyzed and validate the effectiveness of the proposed DC microgrid system.
Keywords: Distributed generation; DG; Islanded DC microgrid; Residential microgrid; Solar PV; Hybrid energy storage system; HESS; Interfacing DC to DC converters.
Design and Implementation of Battery Management System for Lithium-ion Batteries in Electric Vehicles
by Jishna Ramakrishnan, Aji Joy, Sithara Jeyaraj
Abstract: The persistent need for an eco-friendly and sanitaryrnmeans of conveyance are propelling the use of Electric Vehiclesrn(EVs), and Li-ion batteries - which are far advanced than itsrncounterparts are being widely deployed in EVs. Unfortunatelyrnit can be catastrophic suppose they are not utilized insidernthe boundaries set by their safety operation area. Therefore,rna battery Management System (BMS) is significant to protectrnthe battery from damaging, to extend battery life and alsornto ensure that the battery is ready to be used despite thernenvironmental conditions. The proposed project aims to model anrnefficient BMS to maximise their performance and efficiency withrnbattery stack monitor LTC6811 for monitoring battery pack, andrnSTM32F303 Cortex M4 microcontroller. The proposed systemrnperforms measurement of cell voltage, current, temperature, staternof charge, state of health, remaining useful life determination,rnmonitoring and controlling the charge/discharge characteristicsrnand cell balancing.
Keywords: BMS; battery management systems; electric vehicles; lithium-ion batteries; SOC; state of charge; energy technology.
Internet of Things Based Smart Grid: An Overview
by Karan Singh Joshal, Neeraj Gupta, Anuradha Tomar
Abstract: Smart grid (SG) is a huge step forward for revolutionising the traditional grids. The features of the SG help in solving the complications related with the outdated grids. SG has the potential to efficiently integrate renewable energy, provide two-way communication, and store electrical power. But still, SG is considered to be in its nascent stage for getting the maximum benefits from SG. The problem lies within the automation, communication and management of SG. The key for solving this problem is Internet of Things (IoT) which itself is a revolution in digital communication after computers and internet. The main focus of this paper is to confer about the IoT and SG systems. It has also shown the power and information flow within the SG systems. Its main aim is to understand the various benefits, features and application areas of IoT based SG systems.
Keywords: Internet of Things (IoT); Smart Grid (SG); Home area network (HAN); Neighbourhood area network (NAN); Wide area network (WAN); communication technologies.
Quadratic Boost Converter for Wind Energy Conversion System using Back Propagation Neural Network Maximum Power Point Tracking
by Ramji Tiwari, P. Pandiyan, S. Saravanan, T. Chinnadurai, N. Prabaharan, K. Kumar
Abstract: The article presents a DC-to-DC high step-up quadratic boost converter with maximum power point tracking (MPPT) technique using an artificial neural network (ANN) for wind energy transfer systems. In order to get the most possible electrical energy from the wind speed, the proposed topology employs a Back Propagation Network (BPN) based neural network control technique. A quadratic boost converter (QBC) is employed in this system to attain a higher voltage rating, and its performance is tested with a boost converter to determine its efficiency. The proposed system is developed in MATLAB/Simulink platform to demonstrate the operating principle under continuous conduction mode. The results obtained from this proposed system are more favorable as compared with classical Perturb and Observe (P & O). Keywords- Wind energy conversion system (WECS); Quadratic Boost converter (QBC), ANN, MPPT, Permanent Magnet Synchronous Generator (PMSG).
Keywords: Wind energy conversion system; rnPMSG; rnQuadratic Boost converter; rnArtificial Neural Network; rnMPPT.
Special Issue on: ICEE2019 Renewable Energy Utilisation
Assessment of Offshore Wind potential in Morocco
by Houda LAAOUIDI, Mourad NACHTANE, Mostapha TARFAOUI, Mourad TRIHI
Abstract: Assessment of offshore wind resources appears to be urgently needed on grounds of the rapid development of the renewable marine energies. The wind potential of Morocco is important on all coastlines; the offshore wind has clear theory advantages over onshore wind in terms of productivity, and recent advances in offshore wind technology open short-term real possibilities. In this research, a specific study on the evaluation of wind energy resources along the Atlantic coast of Morocco has been developed, utilizing numerical modeling data. To evaluate the spatial distribution of wind power, 18 data points were chosen along this coast. Moreover, the adjustment of wind data and the statement of estimation methods related to form and scale parameters of the Weibull distribution was conducted after a thorough literature review. Then, a study and analysis of wind data based on its speed and direction were carried out, taking into account a five-year period between 2013 and 2017. These study findings denote higher energy production in areas where there is no physical barrier all along the Atlantic Coast, whereas, in the extreme north and southern sites, the energy resource is considerably lower because of the shadow effect of the Iberian Peninsula and the Canary Islands, respectively. Furthermore, wind energy converted to electrical energy is considered to estimate average power at all points studied. Finally, to pick out the most suitable area for wind turbines installation, a multi-criteria analysis is performed taking into account different factors.
Keywords: Offshore wind energy; wind turbine; The wind potential; Wind power density; Weibull distribution function; Electricity Production.
Evaluation of Drying Kinetics and Performance Parameters of Indirect Type Solar Dryer during Drying of Capsicum Annuum
by D. Mallikarjuna Goud, Mugi Vishnu Vardhan Reddy, CHANDRAMOHAN V.P.
Abstract: In this work, an indirect type solar dryer (ITSD) is used to dry Capsicum Annuum (green chilli). Drying kinetics and the performance of ITSD dryer are presented here. The initial moisture content (MCi) of green chilli is 8.3984 kg/kg of dry basis (db). The green chilli is dried from its MCi to the final MC of 0.2218 kg/kg of db in 18 h of drying time. Solar air collector and drying efficiencies were estimated and they were 77.68% and 7.92%, respectively. The average drying rate of 0.4303 kg water/kg of db-h is achieved. The present results were compared with seven existing correlations available from the literature and found that the modified Page model gives a higher correlation coefficient and lower reduced chi-square. The effective moisture diffusion coefficient (Deff) is found to be 1.464 × 10−9 m2/s. The average heat and mass transfer coefficients were estimated from experimental results.
Keywords: Drying efficiency; Indirect type solar dryer; Drying kinetics; Effective moisture diffusion coefficient; Heat and mass transfer coefficients.
Technical and Financial Analysis of Grid-tied Solar PV for Sustainable Irrigation in Rural Agro-Based Communities in Developing Countries: A Case Study in Ghana
by BENSON AHUNU, RICHARD OPOKU, JERRY KPONYO, ERIC AGYEI-ANTWI
Abstract: Energy for irrigation in many developing countries is mainly from thermal power plants or biomass/diesel generators with high operational cost. In this work, studies were conducted on grid-tied solar PV irrigation system with net-metering for three irrigation sites in Ghana using an energy balance model. LCOE of US$ 0.23 0.24 per kWh was obtained for the proposed system compared to average cost of US$ 0.34 per kWh of grid electricity. The financial analysis revealed that for a 20-year period, there are potential cost savings of US$ 1,240,800; US$ 913,900 and US$ 756,350 with the proposed system compared to conventional electricity cost for the three irrigation sites which have energy demands of 242,463 kWh; 189,493 kWh; and 153,183 kWh per year, respectively. It is suggested that for Ghana Government to realize its Planting for Food and Jobs policy, it should invest in cost-effective solar irrigation systems for all-year round farming.
Keywords: sustainable irrigation; grid-tied solar PV; net-metering; levelized cost of energy.
Performance evaluation of hybrid PV/Spiral flow solar collector with CuO/water nanofluid
by R. Gangadevi, S. Senthilraja, B.K. Vinayagam
Abstract: The present study aims to investigate the efficiency of PVT system with spiral flow thermal collector using CuO/water nanofluid as a coolant. The power output of the PV panel is affected negatively by increase in temperature. When the temperature increases the output current exponentially increases whereas output voltage linearly reduces. In order to minimize this negative effect the Coolant fluids are water and CuO/water nanofluid of 0.05, 0.1, 0.2vol% is used in this experimental study. From the experimental results, the thermal and electrical efficiencies of PVT solar collector increases with the increase of volume concentration of nanofluids. It was observed that for 0.2 vol% the electrical efficiency enhanced by 5.3%, In the case of 0.05% and 0.1 vol% of CuO/water nanofluids, the electrical efficiency enhanced by 2.67%, 4.51% respectively. The thermal efficiency of the PVT system for three cases of 0.05, 0.1, 0.2 vol% of CuO/water nanofluids are enhanced by 29.41%, 39.86% and 50.01% with respect to water. The highest overall efficiency of the PVT system was obtained as 95.87% at 0.2 volume concentration. In this study the measurement uncertainty also carried out for the experimental data it shows that the measurements are reliable.
Keywords: Nanofluid; Hybrid solar collector; Spiral flow collector; Thermal efficiency; Electrical efficiency.
Radiation and cross diffusion on unsteady chemically reactive convective flow through an extended surface in heat generating porous medium
by Bhuvaneswari Marimuthu, Sivasankaran Sivanandam, Malarselvi A
Abstract: In the present research work we scrutinized the radiation and cross diffusion influences on unsteady stream through an elongated surface in a heat generating porous medium with chemically reactive process. The PDEs are transfigured into ODEs with the utility of similarity transformation. Runge-Kutta integration procedure together with shooting technique is adapted in this work. The dominations of various parameters are demonstrated with the help of graphical representations. Further numerical discussions for skin drag coefficient, Nusselt number and solute dispersion are investigated.
Keywords: Radiation; Chemical reaction; Cross diffusion; Porous medium; Heat generation.
DETECTION OF HIGH FREQUENCY EMISSION USING ENSEMBLE EMPIRICAL MODE DECOMPOSITION
by Tomina Thomas, Prawin Angel Michael
Abstract: This paper discusses state-of-the-art study of the different methods of
signal processing. Nowadays emissions are rising in the range of high frequencies
due to the rapid development of energy-saving equipment. So much work was under
way in various fields to identify these emissions. Fourier transforms, Short-time
Fourier transforms and Empirical mode decomposition (EMD) are some of the
methods used for the detection process. Apart from these methods Ensemble,
Empirical Mode Decomposition (EEMD) becomes a superior approach for precise
Keywords: ensemble empirical mode decomposition; power quality; short time fourier transform; supra-harmonics.