Characteristics of Heat Resistant Aluminum Alloy Composite Core Conductor Used in overhead Power Transmission Lines

The heat resistant aluminum alloy wire composite material core conductor (ACCC/HW) which was used in overhead transmission lines is developed and studied in this work. The composite material core is carbon fiber/glass cloth reinforced modified epoxy resin composite. Tensile stress tests and stress-strain tests of both composite core and conductor are taken at 25 °C and 160 °C. Sag test, creep test and current carrying capacity test of composite conductor are taken. The stress of composite conductor are 425.2 MPa and 366.9 MPa at 25 °C and 160 °C, respectively. The sag of conductor of 50 m length are 95 mm, 367 mm, and 371 mm at 25 °C, 110 °C, and 160 °C, respectively. The creep strain are 271 mm/km, 522 mm/km, and 867 mm/km after 10 years under the tension of 15% RTS (Rated Tensile Strength), 25% RTS and 35% RTS at 25 °C, and 628 mm/km under 25% RTS at 160 °C, according to the test result and calculation. The carrying capacity of composite conductor is basically equivalent to ACSR (Aluminum Conductor Steel Reinforced). ACCC/HW is suitable in overhead transmission lines, and it has been used in 50 kV power grid, according to the results.

Passive electrical properties of Lupinus angustifolius L. stem TV. The core-conductor theory parametres: space constant λ and time constant τ

On the basis of the core-conductor theory and the method described by Hodgkin and Rushton (1946) for the axon, the space constant K and the time constant T have been determined for the stem of <i>Lupinus</i>. Electrotonic potentials were recorded in the extrapolar region in the vicinity of the cathode along the longitudinal axis of the stem. Extracellular recording electrodes were applied. It was found that the steady-state distribution of potential along the stem surface is of exponential character. The calculated space constant K has a value of 2.0 to 2.4 mm (average 2.1 mm) and is almost identical with the X values for nerves and muscles (mean 1.5-2.0 mm). The values of the time constants ("half-time") of electrotonic potentials increase linearly with the distance from the cathode. The time constant τ calculated on this basis is on the average 5.2 sec and as compared with τ for nerves and muscles is 103 times higher. The phenomena observed in the <i>Lupinus</i> stem fulfill the equations of the core-conductor theory (Appendix). Their character is identical to that of the phenomena noted in nerves or muscles. It is probable that they occur on the membrane of excitable cells of the stem. The results here presented are a, convincing argument indicating that in higher plants an excitable system may exist, subjected to the same laws as that in animal organisms.