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Enhancement of Dielectric strength is an important issue to enhance power system reliability. Insulation filling such as Alumina Trihydrate (ATH) and Silicon dioxide (Sio2) are used to enhance the dielectric strength of polymer insulator. The paper proposes a mathematical model of dielectric strength considering different temperatures and filling percentages using neural network. Moreover, comparison of filling materials is carried out through this model. The comparison shows the superiority of ATH in enhancing the dielectric strength of the polymer. Also, the obtained model will help in getting the best filling concentration without needing to repeat the tests which can be considered as a techno-economical solution to enhance the dielectric strength. Finally, the curve fitting is used to get the dielectric strength model not only as a function of filling concentration percentage but also as a function of temperature. [ABSTRACT FROM AUTHOR]

Assessment of power systems voltage stability is considered an important assignment for the operation and planning of power system. In this paper, a voltage stability study using Continuous Power Flow (CPF) is introduced to evaluate the impact of Distribution Generator (DG) on radial distribution systems. On the way to allocate the DG, a hybrid between the Voltage Stability Index (VSI) and Whale Optimization Algorithm (WOA) is developed. The main purpose of using VSI is to find the most sensitive buses for allocating the DG in the system. Hence, Fuzzy logic control with the Normalized VSI (NVSI) and the voltage magnitude at each bus are used to determine the candidate buses. However, the best DG size is calculated using WOA. Four standard radial distribution systems are used in this paper; 12, 33, 69, and 85-bus. The developed hybrid optimization method is compared with other existing analytical and metaheuristic optimization techniques to prove its efficiency. The results prove the ability of the developed method in the allocation of DG. In addition, the influence of the DG integration on enhancing the voltage stability through injecting the proper active and reactive powers is studied. [ABSTRACT FROM AUTHOR]

Epoxy resin composites reinforced to different types of carbon nano-particles have been fabricated. Carbon black (20, 30 and 40 wt. %), graphene (0.5 to 4 wt. %) and carbon nanotubes (CNT) (0.5 to 2 wt. %) were added with different weight percentages to epoxy. The dielectric strength of composites was tested in several conditions such as (dry, wet, low salinity and high salinity). The mechanical characterization showed that the nano-composite Polymer enhanced by using these particles in the tensile strength. Thermal gravimetric analysis shows effect of these nano-particles on the thermal structure of epoxy resin. Scanning Electron Microscopic test is used to characterize the dispersion of carbon nano-particles and to analysis the fractured parts in the nano scale. [ABSTRACT FROM AUTHOR]

Electrical and mechanical properties of polymer composite materials are investigated through the determination of resistivity and hardness for composites samples. Epoxy composite samples have been prepared with different concentrations of certain inorganic fillers such as; Titanium dioxide (TiO2) and Silica (SiO2), of various size (micro, nano and hybrid) to study the electrical and mechanical behavior. The volume resistivity reaches 3.23×1014 ohm.cm for the micro silica composite. Surface of composite material has been mechanically examined by hardness test. The results show that the resistivity of microcomposites and nanocmposites are increased with the decrease of filler concentration. But the resistivity of hybrid composites is increased with the increase of filler concentration. Maximum hardness value was obtained from hybrid silica composite with 0.1% filler concentration. [ABSTRACT FROM AUTHOR]