scholarly journals Synthesis and Diagnostics of Nanostructured Micaless Microcomposite as a Prospective Insulation Material for Rotating Machines

2019 ◽  
Vol 9 (14) ◽  
pp. 2926
Author(s):  
Jaroslav Hornak ◽  
Václav Mentlík ◽  
Pavel Trnka ◽  
Pavol Šutta

This paper deals with the topic of composite insulation materials for rotating machines and it is primarily pointed to the synthesis of new three-component insulation system. In connection with this research, the basic components of the insulation system are selected and described by different diagnostic methods. The proposed insulation material is composed of epoxy resin based on bisphenol-A diglycidyl ether, magnesium oxide nanofiller (1 wt %) with its own surface treatment technology using epoxysilane coupling agent ( γ -glycidoxypropyltrimethoxysilane) and polyethylene naphthalate as a reinforcing component. Following the defined topic of the paper, the proposed three-component insulation system is confronted with commonly used insulating systems (PET reinforced and Glass reinforced mica composites) in order to verify the basic dielectric properties (dielectric strength, volume resistivity, dissipation factor) and other parameters determined from phenomenological voltage and current signals, respectively.

Author(s):  
Lukmanul Hakim ◽  
T. Haryono ◽  
Suharyanto Suharyanto

Today, insulation system involves more than one insulation material, whether serial, parallel, or both. In insulation system, the simplest form is composite which consists of two layers of the same material. The benefit of using layered insulation is that the dielectric strength is higher than one layer with the same thickness. There are two methods to test bamboo isolator, i.e., tests of the breakdown voltage of bamboo wall and bamboo fiber. The tests used two methods of composite layers (acrylic and resin) and without composite layer (normal condition). The tests were intended to observe the breakdown voltage on each incidence in each test sample and discover the dielectric strength. The test result showed that the breakdown voltage of bamboo wall was bigger than bamboo fiber with or without composite layer. The highest dielectric strengths of acrylic layer in petung bamboo wall were 2.07 kV/mm and acrylic layer in bamboo fiber was 0.95 kV/mm in layered method. Meanwhile, in ampel bamboo wall it was 1.35 kV/mm and petung bamboo fiber it was 0.43 kV/mm in normal condition (without layer).


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Banumathi S. ◽  
Karthik T. S. ◽  
Sasireka M. ◽  
Kiran Ramaswamy ◽  
Vishnu J. ◽  
...  

Epoxy resin mixed with rice husk ash and quartz powder increases its dielectric strength. This paper presents the dielectric properties of the press board coated with this epoxy mixture. In this work, the press board, which is used in the transformer, is coated with three components: epoxy resin, rice husk ash, and quartz powder. The nanometer-sized quartz powder and rice husk ash are mixed in the particular ratio with the epoxy resin. The mixture of epoxy resin, quartz powder, and rice husk ash is coated on both sides of the press board. The dielectric constant, volume resistivity, and Tan Delta (dissipation factor) of the coated press board are compared with the noncoated press board. The results reveal that the coated board is having high dielectric constant and volume resistivity when compared to the noncoated board.


2020 ◽  
Vol 38 (1) ◽  
pp. 189-196
Author(s):  
Arkadiusz P. Dabrowski

AbstractIn this paper, results of investigation on the impact of firing temperature on insulating properties of Low Temperature Cofired Ceramics are presented. Dissipation factor, volume resistivity and breakdown electric field intensity were determined for firing peak temperature in the range from 800 °C to 900 °C. The tests were performed for two commercial LTCC materials: 951 Green Tape (DuPont, USA) and SK47 (Keko, Slovenia). The results showed that the firing temperature had a significant effect on the dielectric loss factor, volume resistivity and lifetime at applied high voltage. No clear tendency was observed for dielectric strength in the analyzed firing temperature range.


2017 ◽  
Vol 50 (1) ◽  
pp. 36-57 ◽  
Author(s):  
Nurul Hidayah ◽  
Mariatti Mustapha ◽  
Hanafi Ismail ◽  
Mohamad Kamarol

This study determines the applicability of nanofillers (silica, boron nitride, and zinc oxide) in linear low-density polyethylene (LLDPE)/silicone rubber (SR) insulation compounds. Design of experiment is adopted to model the relationship between the properties (permittivity, loss tangent, dielectric strength, and volume resistivity) and factors (SR content, type of nanofiller, and nanofiller loading) for performance optimization. It is observed that SR content and type of nanofiller significantly influence the electrical properties of LLDPE/SR nanocomposites. Nanofiller loading, however, causes a small variation in the properties of the nanocomposites except for dielectric strength. From the optimization, it is found that the optimum formulation composition is 10 wt% of SR and 2 vol% of nanoboron nitride.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zhiqiang He ◽  
Heping Xie ◽  
Mingzhong Gao ◽  
Ling Chen ◽  
Bo Yu ◽  
...  

Deep rock is always under high-temperature conditions. However, traditional coring methods generally have no thermal insulation design, which introduces large deviations in the guidance required for resource mining. Thus, a thermal insulation design that utilizes active and passive thermal insulation was proposed for deep rock corers. The rationale behind the active thermal insulation scheme was to maintain the in situ core temperature through electric heating that was controlled by using a proportional-integral-derivative (PID) chip. Graphene heating material could be used as a heating material for active thermal insulation through testing. In regard to the passive thermal insulation scheme, we conducted insulation and microscopic and insulation effectiveness tests for hollow glass microsphere (HGM) composites and SiO2 aerogels. Results showed that the #1 HGM composite (C1) had an excellent thermal insulation performance (3 mm thick C1 can insulate to 82.6°C), high reflectivity (90.02%), and wide applicability. Therefore, C1 could be used as a passive insulation material in deep rock corers. Moreover, a heat transfer model that considered multiple heat dissipation surfaces was established, which can provide theoretical guidance for engineering applications. Finally, a verification test of the integrated active and passive thermal insulation system (graphene heating material and C1) was carried out. Results showed that the insulating effect could be increased by 13.3%; thus, the feasibility of the integrated thermal insulation system was verified. The abovementioned design scheme and test results provide research basis and guidance for the development of thermally insulated deep rock coring equipment.


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