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    Applications of high-voltage resistor based on saline solution in high-voltage impulse generation and measurement
    (2020-01-01)
    Chaisiri, Punyavee
    ;
    Yutthagowith, Peerawut
    This paper presents applications of high-voltage (HV) resistors based on saline solution for HV impulse generation and measurement. The electrical resistivity and relative permittivity of saline solution in the frequency range from 100 Hz to 100 MHz were investigated. The electrical resistivity and relative permittivity were calculated from experimental measurements of the resistance and capacitance of saline solution in a test cell. From the characteristics and the experimental results, the technical data of saline solution with various concentrations of substances were utilized in the design of HV resistors for HV impulse generation and measurement, as a current-limiting resistor and an HV resistor used in an HV part of a voltage divider. Moreover, the developed HV resistors were tested to confirm their effectiveness in HV generation and measurement. From the experimental results, it was found that the developed HV resistors have promising characteristics for practical HV impulse generation and measurement. According to the results of this study, an HV resistor based on saline solution has strong potential for application in HV impulse generation and measurement compared with a conventional voltage divider.
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    The Investigation on Electrical Characteristic of Saline Solution
    (2019-09-01)
    Chaisiri, Punyavee
    ;
    Yutthagowith, Peerawut
    This paper presents the investigation of electrical characteristic of saline solution in the term of electrical resistivity and relative permittivity in the frequency range from 100 Hz to 100 MHz. The electrical resistivity and relative permittivity are calculated from resistance and capacitance of saline solution. The experimental results provide the technical data of the insulating liquid which is very useful for liquid insulator design applied for a part of high volt component.
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    Reinvestigation the thermal and electrical transport properties of Tl7Sb2
    (2013-10-29)
    Charoenphakdee, Anek
    ;
    Harnwunggmoung, Adul
    ;
    Seetawan, Tosawat
    ;
    Rattanapun, Chesta
    ;
    Amornkitbamrung, Vittaya
    The authors examined the thermal and electrical transport properties of Tl<inf>7</inf>Sb<inf>2</inf> at temperatures ranging from room temperature to 400 K. The crystal system of Tl<inf>7</inf>Sb<inf>2</inf> is cubic with the lattice parameter a = 1.16053 nm and the space group is Im3m. The polycrystalline samples were prepared by melting stoichiometric amounts of thallium and antimony. Although, usually the thermal conductivity of thallium compounds is very low (<1 Wm<sup>-1</sup>K<sup>-1</sup>), that of Tl<inf>7</inf>Sb<inf>2</inf> was relatively high (~13 Wm<sup>-1</sup>K<sup>-1</sup> at room temperature). This is because of the large electronic contribution to the thermal conductivity. © (2013) Trans Tech Publications, Switzerland.
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    Designing apparatus for highly precise measurement of electrical conductivity and seebeck coefficient from 85 k to 1200 k
    (2013-10-04)
    Budngam, Sopon
    ;
    Wichainchai, Aree
    ;
    Pimmongkol, Saichol
    ;
    Tipparach, Udom
    We describe the development of apparatus for measuring of electrical conductivity and Seebeck coefficient with high precision from 85 K to 1,200 K. Electrical resistance was measured by means of four-point probe method as a function of temperature. The temperature below 400 K was measured by using type T thermocouple in vacuum system was used and from 400 to 1,200 was measured by using Type S was applied for temperature between 400 and 1200 Kelvin in an inert gas system. With the dimensions of the specimen, the electrical resistivity (ρT) can be obtained in the unit of microohm-centimeter (μΩ - cm) and be written in polynomial, ρ<inf>T</inf> = -0.3191 + 6.8 × 10<sup>-3</sup>T - 6.0 × 10<sup>-7</sup> T<sup>2</sup> + 8.0 × 10<sup>-10</sup>T<sup>3</sup>. The electrical conductivity can be obtained by taking inversion of the electrical resistivity. Seebeck coefficient (α<inf>T</inf>) can be calculated in microvolt per Kelvin as follows: α<inf>T</inf> = 1.9653 - 1.49 × 10<sup>-2</sup>T + 9.0 × 10<sup>-5</sup>T<sup>2</sup> - 2.0 × 10<sup>-7</sup>T<sup>3</sup> + 2.0 × 10<sup>-10</sup>T<sup>4</sup> - 1.0 × 10<sup>-13</sup>T<sup>5</sup> + 3.0 × 10<sup>-17</sup>T<sup>6</sup> when T is temperature in K. The Seebeck coefficient data was compared with X-ray diffraction (XRD) and X-ray fluorescence (XRF) of the specimen. The result showed that our developrd apparatus yields the same as standard method when copper with purity greater than 99 percent was employed. © (2013) Trans Tech Publications, Switzerland.