http://nopr.niscpr.res.in/handle/123456789/59429 2026-10-06T05:23:10Z 2026-10-06T05:23:10Z Shobeiry, Seyed Mohammad Ameli, Mohammad Taghi Oveysikian, Ali Rahimi, Ali http://nopr.niscpr.res.in/handle/123456789/59440 2022-04-05T11:53:53Z 2022-04-01T00:00:00Z

Title: Adaptive Voltage and Current Control to Improve Stability and Restoration of Operation after the Occurrence of a Transient Fault in The Inverter-based Standalone Microgrid Authors: Shobeiry, Seyed Mohammad; Ameli, Mohammad Taghi; Oveysikian, Ali; Rahimi, Ali Abstract: Small signal stability analysis and control strategies are well provided for conventional power systems. Still, in inverter-based microgrids, it is necessary to determine the model features and control specific oscillation modes. In this paper, inverter-based standalone microgrid performance modelling, including voltage and current control, has been developed. This model has inverter control loop details but does not provide switching performance. A simple adaptive controller controls the microgrid voltage and current, with only three parameters, including two negatively stable feedbacks and positive unstable feedback. Advantages of this controller over a Proportional Integral Derivative (PID) controller include proper adaptation to system changes, flexibility in setting up, and a robust deal with sudden changes in the system. Finally, by making drastic changes in the operation of a sample microgrid, such as loading and short circuit faults, we prove the effectiveness of the proposed adaptive control scheme in improving the stability and restoration of operation after the occurrence of a transient fault in the microgrid. Page(s): 339-348

2022-04-01T00:00:00Z Nnodim, Chiebuka T Kpu, Gerald Cham Okhuegbe, Samuel N Ajani, Ayodeji A Adebayo, Segun Diarah, Reuben S Aliyu, Samuel J Onokwai, Anthony O Osueke, Christian O http://nopr.niscpr.res.in/handle/123456789/59439 2022-04-05T11:51:42Z 2022-04-01T00:00:00Z

Title: Figures of Merit for Wind and Solar PV Integration in Electricity Grids Authors: Nnodim, Chiebuka T; Kpu, Gerald Cham; Okhuegbe, Samuel N; Ajani, Ayodeji A; Adebayo, Segun; Diarah, Reuben S; Aliyu, Samuel J; Onokwai, Anthony O; Osueke, Christian O Abstract: In future electrical grids, high levels of Variable Renewable Energy (VRE) penetration including solar photovoltaics (PV) and wind energy is expected. This poses a challenge in system operation and planning especially in balancing electricity demand and supply. This paper examines figures of merit for wind and solar integration in electricity grids. Quantitative tools such as load duration curves, correlation analyses, and the Fourier transform were used to study the intermittency/variability of wind and solar PV power. Time series data on power production from the European Network of Transmission System Operators for Electricity (ENTSO-E), and Réseau de Transport d'Électricité (RTE) were used for the analyses. The analyses illustrate that despite the valuable amount of energy that can be obtained from wind and solar PV, these energy sources cannot be used as baseload power supply. Solar PV power is available for approximately 50% of the time year-round. Wind power output on the other hand can reach very small magnitudes of just a few megawatts several times in a year. More to that, wind is positively correlated over long distances, even exceeding 3000 km and aggregating wind fleets over a large geographic area might not guarantee continuous availability of wind power. Nonetheless, these sources can still be integrated in electricity grids in high proportions, provided intermittency mitigation options such as energy storage, curtailment, and demand-response are implemented. Page(s): 349-357

2022-04-01T00:00:00Z Gupta, Mahesh Kumar Mahapatra, Rajendra Prasad Panwar, Vinay http://nopr.niscpr.res.in/handle/123456789/59438 2022-04-05T11:48:49Z 2022-04-01T00:00:00Z

Title: Effect of Temperature and Strain Rate Variation on Tensile Properties of a Defective Nanocrystalline Copper-Tantalum Alloy Authors: Gupta, Mahesh Kumar; Mahapatra, Rajendra Prasad; Panwar, Vinay Abstract: Nanocrystalline alloys of immiscible in nature are emerging topics of interest for researchers due to better mechanical stability at high temperatures. Nanocrystalline Copper-Tantalum alloy is of particular interest for research exploration due to its high strength, limited solubility and high-temperature stability. In the present work, the mechanical properties of nanocrystalline 90/10 copper-tantalum (9Cu-Ta) alloy have been investigated using the molecular dynamics approach. Embedded atom method (EAM) of potential has been used to analyze the mechanical properties at high temperatures due to the high stability of EAM in molecular dynamic simulation. At high-temperature defects plays a very important role therefore a specific 9Cu-Ta nanostructure having 3% vacancies has been selected to explore its performance under a particular type of point defect. This study has been conducted under uniaxial tensile loading. The tensile properties of this defective nanocrystalline alloy have been compared at specific temperatures i.e. 300 K, 600 K, 800 K, 1000 K and 1200 K. The study revealed that the variation in temperature from 300 K to 1200 K results in the shifting of the stress-strain graph to lower stress values. It has also been noticed that the variation in ultimate tensile strength is the least in comparison to yield strength and elastic constant for the same variation in temperature. These results indicate the importance of avoiding thermal agitations during the synthesis and surface modification of nanocrystalline copper-tantalum alloy. Page(s): 358-366

2022-04-01T00:00:00Z Yang, Zhonghua Fu, Gui Li, Hua http://nopr.niscpr.res.in/handle/123456789/59437 2022-04-05T11:46:51Z 2022-04-01T00:00:00Z

Title: Synthesis of DC–3074 and Z–1 Silicones Modified Epoxy Resin and Comparison of Salt Spray Resistance Authors: Yang, Zhonghua; Fu, Gui; Li, Hua Abstract: In order to improve the chemical resistance of epoxy resin and its toughness and corrosion resistance, in this paper, silicone modified epoxy resin was prepared with epoxy resin and two kinds of silicones, Dow Corning DC–3074 and Chenguang Z–1, as raw materials and dibutyltin dilaurate (DBTDL) as catalyst. The structure of the modified epoxy resin was characterized by Fourier transform infrared (FTIR) spectrometer and its performance was tested. The results showed that the epoxy resin modified by DC–3074 had better salt spray resistance compared with the Z–1. Therefore, the DC–3074 was selected as the epoxy resin E–51 modifier. The silicone modified resin was further synthesized with E–51 as the matrix resin, 12.5% DC–3074 silicone as the modifier, and 0.5% DBTDL as the catalyst. The obtained cured coatings showed good performance with the following results: product fineness of 20–25 μm, solid content of more than 95%, surface drying time of 25 min, smooth appearance, hardness of 2 H, adhesion level of 0, and salt spray resistance time of 432 h. The prepared modified epoxy resin coating has good salt spray resistance and good application prospect. Page(s): 367-373

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