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Issues related to stable microgrid (MG) operation often pose challenges for engineers and researchers, including energy management, power quality maintenance, and the effect of perturbations. Therefore, continuous measurement and monitoring of the system's stability level require special attention. Thus, motivated and focused on addressing these issues, this paper presents a novel decision-making methodology for determining the MG stability index (MGSI) to comprehensively measure the MG stability level. The proposed index is based on continuously measuring fundamental MG parameters, including voltage, frequency, battery state of charge (SOC), and total harmonic distortion. The influence of these parameters on system stability is considered using 256 rules in a Mamdani-based fuzzy inference system. The proposed methodology is evaluated through seven case studies considering different modes of MG operation, types of loads, and availability of power sources and simulated using MATLAB Simulink software. The results demonstrate variations in MGSI for different investigated scenarios, such that a grid-connected MG system with high renewable output and high battery SOC, along with critical/noncritical load, exhibits the best MGSI compared to an islanded MG system with low renewable output, low battery SOC, and an inductive load that shows least MGSI. Additionally, to demonstrate the credibility of the fuzzy-based controller in complex decision-making, a comparative analysis is performed with the analytic hierarchy process under the multi-criteria decision-making technique. The paper also includes sensitivity analysis that reflects the system's sensitivity to different input sources and robustness analysis of the controller. [ABSTRACT FROM AUTHOR]

In this research, a vegetable-based oil blend has been subjected to thermal ageing for different time periods before and after being dispersed with graphene oxide nanoparticles and its dielectric breakdown is investigated and compared with the newly developed unaged samples. Results show that at peak values, the ac breakdown voltage of nanofluids decreases by just 2.6% after ageing when compared to the base oil for which the ac breakdown voltage decreases by 8.4% after ageing. Similarly, at peak value, the impulse breakdown voltage of nanofluid decreases by just 2.9% after ageing as compared to the base oil for which the impulse breakdown voltage decreases by 7.3%. Thus, the developed nanofluid can be potentially used in transformers with successful operation after analyzing the physio-thermal properties. [ABSTRACT FROM AUTHOR]

Rural and remote area electrification is of grave concern around the globe. Therefore, well-planned and cost-effective microgrids integrating renewable energy sources are emerging as effective solutions. However, the microgrid's stable operation and its future deployment is affected by the perturbations caused due to uncertainity in renewable sources, dependency on the battery state of charge, and load variation. So, considering the possible concerns affecting the planning and development of a microgrid for any given region, this paper proposes a comprehensive performance assessment of the hybrid residential microgrid based on a load model of Kibber village in Himachal Pradesh, India. The proposed approach is divided into three parts for the best planning of microgrids. Firstly, the MATLAB–Simulink software technically analyzes the system performance under perturbations considering the available renewable sources. Secondly, an economic analysis using HOMER Pro software is done to examine the cost-effectiveness of the proposed microgrid model through the simulation of electrical loads for Kibber village, considering the available renewable sources. Lastly, a real-time analysis of the proposed prototype of programmable logic controller-based hardware test bench has been developed, aiming for future regional microgrid deployment. System voltage, frequency, power shared, percentage of load met, energy cost, available renewable energy resource, etc. have been considered for validating the proposed controller. The proposed comprehensive assessment of the microgrid model is reproducible with necessary modifications for any geographical location. It will be helpful for its future deployment aiming at rural and remote electrification. [ABSTRACT FROM AUTHOR]

In recent times, with the increase in the penetration of various renewable energy sources (RESs) into power systems, the complications related to the stability issues have increased. The main contribution of this paper is an in‐depth analysis of research in microgrid based on small‐signal, transient, and voltage stability. The small‐signal stability has been discussed based on uncertain load, limitation in power generation capacity, and nature of sluggish feedback observed in few microgrid systems. Instability caused by a transient phenomenon in microgrid has been thoroughly analyzed for losses in distributed energy resources (DERs), islanding and transition modes of operation, load shedding, and faults causing instability. The voltage fluctuations are duly considered in the perspective of load shedding, type of loads, power unbalancing, and different types of faults in microgrid systems. The existing controllers have been compared based on steady‐state error, response time, and robustness etc. The voltage, frequency, and active/reactive power control are analyzed based on centralized, decentralized, hierarchal/distributed control schemes aiming stabilization of microgrid systems. Finally, stability improvement features have been explored in detail, finding the implementation of microgrid stabilizers, energy storage devices, FACTS devices, load balancing, resource forecasting including the adaptive controller. Hence, the uniqueness of this paper can be considered as a state‐of‐the‐art review of the abovementioned stability components in the microgrid system which is not available in the published literature with a similar amount of vastness. [ABSTRACT FROM AUTHOR]

Types I, III and IV wind distributed generators show different and wide range of current sharing capacity during the occurrence of faults in the distribution feeders. In a hybrid microgrid consisting of any of the above mentioned types of wind distributed generators and photovoltaic distributed generators, the fault current in a feeder shows different behaviour which changes as per the type of distributed generators, grid/islanded connection of microgrid operation, distance of the fault from the point of common coupling and nature of the loads in the microgrid system. The novel contribution of this paper is the implementation of a fuzzy logic based adaptive protection scheme through analysis of the q0 components of fault current which are used to detect the low X/R ratio of distributed generators, modes of operation, transient reactance during the series and shunt faults in types I, III and IV wind turbines and PV integrated hybrid microgrid. Considering q0 components and transient reactance, a new relation between the relay current settings and modes of operation has been identified for adaptive relaying. The effectiveness of the proposed adaptive protection scheme for the hybrid microgrid is verified through a simulation case study using Matlab -Simulink software. [ABSTRACT FROM AUTHOR]

Apparently, battery energy storage (BES), intelligent protection and power quality are considered as independent issues. These three factors can be interlinked effectively for control of microgrid through automated demand side management (ADSM). In this context, the proposed approach may change the conventional way for microgrid operation and control giving priority to the power quality issues considering protection and BES systems. The control algorithm is implemented through fuzzy inference system based power quality monitoring index and ADSM. As a part of intelligent protection, logic table for circuit breaker (CB) coordination has been developed without/with backup for relay devices to provide ADSM. The model has been simulated using Matlab-software and validated experimentally using OPAL-RT OP4510 real-time simulator through the assessment of power quality-related parameters such as voltage, frequency, total harmonic distortion and power factor. The results are found satisfactory showing the feasibility of the proposed microgrid model. [ABSTRACT FROM AUTHOR]

Apparently, battery energy storage (BES), intelligent protection and power quality are considered as independent issues. These three factors can be interlinked effectively for control of microgrid through automated demand side management (ADSM). In this context, the proposed approach may change the conventional way for microgrid operation and control giving priority to the power quality issues considering protection and BES systems. The control algorithm is implemented through fuzzy inference system based power quality monitoring index and ADSM. As a part of intelligent protection, logic table for circuit breaker (CB) coordination has been developed without/with backup for relay devices to provide ADSM. The model has been simulated using Matlab‐software and validated experimentally using OPAL‐RT OP4510 real‐time simulator through the assessment of power quality‐related parameters such as voltage, frequency, total harmonic distortion and power factor. The results are found satisfactory showing the feasibility of the proposed microgrid model. [ABSTRACT FROM AUTHOR]

The power quality issues are challenging in microgrid due to the presence of various types of renewable energy resources unlike conventional power system. So, the main objective of this research is to quantify the power quality considering the fuzziness in variation of voltage, frequency, power factor and total harmonic distortion (THD) due to the occurrence of voltage sag, swell, interruption and unbalancing in three-phase AC microgrid feeding static and rotational loads. Therefore, a novel power quality monitoring index (PQMI) is proposed to determine the status of power quality. Total 256 numbers of rules are formed for fuzzy inference system (FIS) to assess PQMI considering the acceptable limits of above mentioned four input variables as per IEEE/IEC standards. The proposed methodology is verified through Mamdani and Sugeno type FIS using Matlab-Simulink software. It is also found that the proposed PQMI is significant to define the status of microgrid even during transition from grid-connected to islanded mode and vice-versa. [ABSTRACT FROM AUTHOR]

Fault ride through (FRT) capability is an essential practice as per the present grid code demands for grid-connected renewable energy-based distributed energy resources. Studies on FRT capability for grid-connected hybrid systems are rarely found. This study considers a wind energy conversion system and a fuel cell system interconnected at a common dc bus. It proposes a new feed-forward-based FRT control scheme for the inverter control where new current references in dq-axis frame are derived by tracking the positive sequence power. The newly derived references are fed forward to the input of the current regulator of the voltage source inverter. Second, fuzzy logic-based current controllers are suggested to improve the tracking capability of the current references in the inverter control scheme so as to enhance the FRT capability of the hybrid system as a whole. The proposed feed-forward-fuzzy control scheme for achieving an enhanced FRT capability is compared with the conventional dq current control and feed-forward FRT control for various grid voltage sag tests, where the performance of the combined feed-forward-fuzzy control is found better. The validation of the proposed FRT control scheme is performed in MATLAB-Simulink environment. [ABSTRACT FROM AUTHOR]

The dynamic behaviour of microgrid system under faulty conditions makes adaptive protection a general necessity for reliable microgrid operation. In design of adaptive protection, the grid-connected and islanded modes have immense importance including grid-connected mode without distributed generators (DGs) in microgrid. In this study, a new adaptive protection scheme is proposed based on the above-mentioned modes of microgrid operation. The proposed method considers nature of DGs connected, fault location detection and fault nature identification based on quadrature and zero sequence components of fault current considering impact of X/R ratio of DGs. The proposed methodologies for adaptive protection schemes are verified in Matlab-Simulink environment and the results are found to be satisfactory while various faults are simulated at different nodes of the microgrid model. At the time of verification of effectiveness of the proposed methodologies, the time derivative of quadrature and zero-axis components of fault current are considered sufficient to instantaneously detect the fault location and fault nature in microgrid system. [ABSTRACT FROM AUTHOR]

The dynamic behaviour of microgrid system under faulty conditions makes adaptive protection a general necessity for reliable microgrid operation. In design of adaptive protection, the grid‐connected and islanded modes have immense importance including grid‐connected mode without distributed generators (DGs) in microgrid. In this study, a new adaptive protection scheme is proposed based on the above‐mentioned modes of microgrid operation. The proposed method considers nature of DGs connected, fault location detection and fault nature identification based on quadrature and zero sequence components of fault current considering impact of X/R ratio of DGs. The proposed methodologies for adaptive protection schemes are verified in Matlab‐Simulink environment and the results are found to be satisfactory while various faults are simulated at different nodes of the microgrid model. At the time of verification of effectiveness of the proposed methodologies, the time derivative of quadrature and zero‐axis components of fault current are considered sufficient to instantaneously detect the fault location and fault nature in microgrid system. [ABSTRACT FROM AUTHOR]

Abstract To find a sustainable approach to surplus rice straw utilization a comparative study of various technologies with simultaneous economic and environmental evaluation is essential. In this article Life cycle assessment (LCA) tool is applied for processing of surplus rice straw considering various advanced techniques: incineration, gasification, anaerobic digestion (AD), fermentation and integrated operation of fermentation and AD. Considering the virtual performance of the existing plants for electricity and ethanol production in India the simultaneous economic and environmental evaluation of each technique is presented. Global warming, acidification, photochemical oxidation and eutrophication categories are considered for environmental impact assessment. The conceptual analysis depicts that gasification has a maximum tendency to reduce the overall environmental impact followed by AD, incineration, integrated operation and fermentation. The integrated operation shows the maximum economic benefit of INR 1525.57/tonne ($ 23/tonne) followed by fermentation, gasification, incineration and AD. The use of surplus rice straw for electricity and ethanol production can reduce the environmental pollution and can contribute to the economic growth of the nation. Graphical abstract Image 1 Highlights • Presented incineration, gasification, AD and fermentation for rice straw processing. • Proposed economic and environmental evaluation of selected technologies in India. • Analysed above technologies using LCA in environmental and economic terms. • Proposed sustainable utilization of rice straw for energy generation. [ABSTRACT FROM AUTHOR]

Industrial ecology based symbiotic system approach is applied to Indian municipal solid waste (MSW) for population size of one million, taking various alternative techniques: anaerobic digestion (AD), compost, refuses derived fuel (RDF), incineration and gasification. Considering the virtual operation of the existing plants for production of electricity and products, the economic and environmental evaluation of each technique is presented. For environmental impact assessment global warming, acidification, photochemical oxidation and eutrophication categories are considered. The conceptual analysis depicts that AD has maximum tendency to reduce global warming (123 tonne CO 2 eq./day) along with the economic benefits of 19099 INR/day (293 $/day). Gasification shows maximum reduction in acidification, photochemical oxidation and eutrophication by 189 kg SO 2 eq./day, 33 kg C 2 H 4 eq./day and 12 kg PO 4 eq./day with economic benefits of 46956 INR/day (722 $/day). Integrated operation of AD and gasification gives maximum economic benefits (INR 66056/day or 1016 $/day) with highest reduction in environmental impact (for all categories) as compared to a single technology and any other combination of technologies. Industrial ecology approach for MSW management system affects the economic and environmental results to significant level that can influence the policy and decision making. [ABSTRACT FROM AUTHOR]

To find a sustainable municipal solid waste (MSW) management and renewable electricity generation system is need of the hour. In modern hybrid electricity generation systems, the use of MSW on priority is not evaluated yet. To satisfy this need, a small scale MSW based microgrid is proposed and evaluated in economic and reliability terms. First, the waste of the selected city is characterized considering four seasons summer, spring, autumn and winter for a complete year. Then a microgrid system is designed using MSW processing techniques namely, anaerobic digestion (AD) and gasification that are further integrated with solar photovoltaic (PV) system, battery and the main grid. The size of the microgrid is optimized using an artificial bee colony (ABC) algorithm targeting the configuration that meets the desired system reliability requirements with minimum cost. The proposed system found as a sustainable approach to process the MSW of a small city (0.1 million population) and a reliable mean to fulfill the electricity demand of a village having 225 houses in India. The annualized system cost (ASC) of the proposed hybrid system found to be INR 5760919 with levelized cost of electricity (LCOE) 5.65 INR/kWh (0.0737 USD/kWh). The total MSW landfilling avoided cost is 451898.9 INR/year that is 17% of its processing cost. [Display omitted] • Proposed sustainable utilization of municipal solid waste for electricity generation. • Municipal solid waste based microgrid is conceptualized and optimized. • Proposed system is evaluated in economic and reliability terms. • The system avoids a significant amount of investment for landfilling of waste. [ABSTRACT FROM AUTHOR]

Abstract: The concept of integration of distributed energy resources for formation of microgrid will be most significant in near future. The latest research and development in the field of microgrid as a promising power system through a comprehensive literature review is presented in this paper. It shows a broad overview on the worldwide research trend on microgrid which is most significant topic at present. This literature survey reveals that integration of distributed energy resources, operation, control, power quality issues and stability of microgrid system should be explored to implement microgrid successfully in real power scenario. [Copyright &y& Elsevier]

A microgrid is an integrated form of distributed energy resources (DERs) which are connected together to serve electrical power to the selected consumers or can exchange power with the existing utility grid suitably under standalone or grid connected mode. The microgrid can be cited as a physical system which is a combination of DERs such as, Photovoltaic Generator, Wind turbine, Fuel Cell, Microturbine etc. and can be modelled with suitable assumptions depending upon specific operational condition to be studied. Interconnection of several kinds of power sources would impact the quality of power within the microgrid. Since voltage and frequency are not the only factors for a system delivering good quality power, the capacity of the same to withstand instability due to transient condition is one of the prime factors to be considered to accept a system as a stable system. Before practical integration of distributed energy resources, it would be essential to check the stability of the system at the design stage. In this paper, the authors have presented the microgrid based on control system engineering. To represent the individual components of microgrid, the DERs (Distributed Energy Resources) have been represented with their transfer functions and they have been simulated using Simulink-Matlab. To observe the response of the DERs, the frequency fluctuation due to step and random change in output power/load are considered as the main factors for stability analysis. All the DERs are integrated forming the microgrid which is represented with an equivalent transfer function based model. The models are studied and results are discussed with the waveforms. This paper shows one feasible method to check the dynamic stability of a proposed microgrid. [ABSTRACT FROM AUTHOR]

In many countries, the farmers find open burning is the cheapest and easiest way for removing large loads of the produced rice straw causing environmental pollution. So, finding a sustainable rice straw management system is need of the hour. In modern hybrid electricity generation systems, the use of rice straw on priority is not evaluated yet. To satisfy this need, this article proposes conceptualization and techno-economic evaluation of a small-scale rice straw based microgrid that processes the surplus rice straw of a village having 250 houses and 900 acres of cultivated land for power generation. The system is capable to process the 1128 tonne/year of 1surplus rice straw and meet the electrical load demand of the same village. The gasification technique is used to process the rice straw, which is further integrated with solar, battery and the utility grid. The optimum size of the microgrid is found using artificial bee colony algorithm. The economic evaluation of the proposed microgrid is organized on the basis of net present cost, annualized system cost and levelized cost of electricity (LCOE). The LCOE of the proposed system is found to be acceptable which is 6.70 INR/kWh (0.089 $/kWh). [Display omitted] • Proposed sustainable utilization of surplus rice straw for electricity generation. • Rice straw based microgrid is conceptualized and optimized for a rural community. • Proposed system is evaluated in economic and reliability terms. • The proposed system is found economically feasible and reliable. [ABSTRACT FROM AUTHOR]

Graphene oxide is one of the latest in- trend nanomaterials in the field of nanotechnology which is being studied in various engineering fields. Yet, its effects on the transformer solid insulation remain unexplored. In this research, the transformer pressboard and Kraft paper are impregnated with nonconductive graphene oxide dispersed vegetable ester-based insulating nanofluid and the behavior of impregnated solid insulation is studied under different thermal aging conditions. The results show that after 60 days of aging, the crystallinity of nanofluid impregnated pressboard is 24.9% more than that of the base oil-blend (OB) impregnated pressboard whereas the crystallinity of nanofluid impregnated Kraft paper is 3.8% more than that of the base OB impregnated Kraft paper. In terms of dielectric properties, the ac breakdown voltage (BDV) of nanofluid impregnated pressboard and Kraft paper is 29.5% and 41% more than the OB impregnated pressboard and Kraft paper, respectively. The dielectric stress is more uniform in nanofluid-based insulation system as compared to the base OB-based insulation system leading to a better design clearance. Therefore, graphene oxide dispersed ester oil (EO)-based nanofluid impregnated solid insulation has better mechanical and dielectric properties, thus leading to an increased lifespan of the transformer. [ABSTRACT FROM AUTHOR]

In this work, graphene oxide nanoparticles are dispersed in different concentrations in a soyabean extracted natural ester-based oil-blend having mineral oil as secondary oil and the resulting nanofluids are tested for various dielectric and physio-thermal properties. The results show that with the addition of nanoparticles, the breakdown voltage of nanofluids increases up to 42% as compared to pure mineral oil, 17% as compared to pure ester oil and 15% as compared to the base oil-blend. Relative permittivity and dissipation factor parameters follow a similar trend as well. Thus, the prepared nanofluids can be used as alternative insulating oils in place of the conventional mineral oil in oil-filled transformers. [ABSTRACT FROM AUTHOR]

To overcome range anxiety problem of electric vehicles (EVs), an accurate real-time energy consumption estimation is necessary, which can be used to provide the EV's driver with information about the remaining range in real time. A hybrid CNN–BDT approach has been developed, in which convolutional neural network (CNN) is used to provide an energy consumption estimate considering the effect of temperature, wind speed, battery's SOC, auxiliary loads, road elevation, vehicle speed and acceleration. Further, bagged decision tree (BDT) is used to fine-tune the estimate. Unlike existing techniques, the proposed approach does not require internal vehicle parameters from manufacturer and can easily learn complex patterns even from noisy data. The comparison results with existing techniques show that the developed approach provides better estimates with least mean absolute energy deviation of 0.14. [ABSTRACT FROM AUTHOR]

Power generation from a grid-integrated renewable energy generator embedded with backup sources to form a hybrid energy system possesses convincing features of high efficiency and zero emissions. Control for felicitating apt power sharing and for providing ancillary services such as low voltage ride through (LVRT) is necessary for the compliance of grid codes. However, the simultaneous control coordination for meeting these control objectives is challenging due to the dynamic nature of renewable generators and utility grid. Hence, this paper proposes an integrated power management strategy (PMS) and LVRT control scheme for such systems. A wind energy conversion system backed up by a battery energy storage system, proton exchange fuel cell, and electrolyzer is considered in this work. A reduced rule-based power management control scheme is proposed for the considered system where the request made by the grid operator is kept in priority. Further, a dynamic current feed-forward based LVRT control scheme based on negative sequence current minimization is presented for the grid-interfaced inverter. The inverter control is coupled with an inherent mode selection capability between the grid feeding mode and LVRT mode in order to realize the proposed integrated control objectives. The validation of the proposed PMS and LVRT control is justified by detailing relevant mathematical control models and also by realizing practical case scenarios such as variable wind speed, load demand, grid power request, and occurrences of balanced and unbalanced voltage sag. The obtained simulation results show the cordial response of the system with the proposed control strategies. [ABSTRACT FROM AUTHOR]

The microgrid central controller has most important role for satisfactory automated operation and control of microgrid while working in grid connected and islanded modes. The central controller has several features for proper coordination of distributed energy resources as per their power generation capacity to serve the critical and non-critical loads. It also initiates the protection techniques at the time of occurrence of severe short circuit fault at the grid end or in microgrid thus ensuring stability and reliability. This paper presents a comprehensive literature review on microgrid central controller. The evolution and advancement of microgrid central controller technology is explored and presented in a compact form. The classification of microgrid central controllers is proposed based on the outcomes found in the process of review. The role of central controller in the domains of microgrid protection, stability and power quality are also explored and summarized. This literature review may be considered as an initial platform for research work on microgrid central controller. [ABSTRACT FROM AUTHOR]

Traffic management in a city has become a major problem due to the increasing number of vehicles on roads. Intelligent Transportation System (ITS) can help the city traffic managers to tackle the problem by providing accurate traffic forecasts. For this, ITS requires a reliable traffic prediction algorithm that can provide accurate traffic prediction at multiple time steps based on past and current traffic data. In recent years, a number of different methods for traffic prediction have been proposed which have proved their effectiveness in terms of accuracy. However, most of these methods have either considered spatial information or temporal information only and overlooked the effect of other. In this paper, to address the above problem a deep learning based approach has been developed using both the spatial and temporal dependencies. To consider spatio-temporal dependencies, nearby road sensors at a particular instant are selected based on the attributes like traffic similarity and distance. Two pre-trained deep auto-encoders were cross-connected using the concept of latent space mapping and the resultant model was trained using the traffic data from the selected nearby sensors as input. The proposed deep learning based approach was trained using the real-world traffic data collected from loop detector sensors installed on different highways of Los Angeles and Bay Area. The traffic data is freely available from the web portal of the California Department of Transportation Performance Measurement System (PeMS). The effectiveness of the proposed approach was verified by comparing it with a number of machine/deep learning approaches. It has been found that the proposed approach provides accurate traffic prediction results even for 60-min ahead prediction with least error than other techniques. • Deep learning based approach has been developed for multistep traffic prediction. • A neighbor selection algorithm has been used to extract spatio-temporal features. • Latent space mapping is used to map latent features of source and target domain. • The approach was tested on real traffic data of two cities from California, USA. [ABSTRACT FROM AUTHOR]

• Bio-degradable vegetable-based oils are 3rd generation insulating fluids in order to replace conventional mineral oil. • Dispersion of TiO 2 and ZnO results in enhancement of dielectric properties of vegetable oil based oil-blends. • Detailed statistical analysis of Weibull data regarding the failure probabilities confirms the experimental results. • TiO 2 and ZnO dispersed vegetable oils can be used as insulating fluids to improve the rating of transformers. Mineral oil being the most extensively used oil in transformers still has some associated drawbacks like non-biodegradability and low fire point. Bio-degradable, non-toxic and fire-resistant vegetable-based ester oils are considered as second-generation insulating fluids. These oils are continuously being tested in order to replace the conventional mineral oil for insulation purposes. The dielectric properties of these vegetable oils are further improved by adding various types of nanomaterials. This paper focuses on preparing a mixture of natural ester oil and mineral oil blend as a base fluid and studying the dielectric behavior of this fluid after being dispersed with TiO 2 and ZnO nanoparticles. Results indicated that dispersion of both nanomaterials resulted in an overall enhancement in the dielectric properties of nanofluids. The breakdown voltage of TiO 2 dispersed nanofluid is reported to be about 30% greater than pure mineral oil, 24% greater than pure ester oil, and 17% greater than the oil-blend. Likewise, the breakdown voltage of ZnO dispersed nanofluid is observed to be around 28% greater than pure mineral oil, 19% greater than pure ester oil, and 16% greater than the oil-blend. Moreover, in terms of cooling, TiO 2 dispersed oil-blend shows better performance as a coolant. Thus, both types of nanofluids can be used as insulating oils in the transformer depending upon the requirements expected to be met by the transformers. [ABSTRACT FROM AUTHOR]