Iwa Garniwa

Thermal Incremental And Time Constant Analysis On 20 Kv XLPE Cable With Current Vary

In power cable, thermal factor must be considered where heat generated in power cable must be limited and lower than thermal rating of insulation materials. Overheating on cable insulation material will cause the electrical insulation aging is accelerated. This paper is present the result of thermal incremental test of the medium voltage XLPE cable type N2XEBY with three core and analysis when time constant come. From the test, temperature rise data is obtained transient condition to steady-state condition and time constant. A cable loaded with constant alternating current in one of its core, and measured the temperature of conductor (Tc), insulation material (Ti ) and the outer surface of the cable (Tp). Base on the test, Conductor is faster than insulation material and surface of cable to reach to thermal time constant, but They have same typical of graph. When current is raised from 90 A to 300 A, time constant is decrease and increase depend of current value and typical for all material. In this paper shown predict correlation of the steady-state temperature and time constant, then empiris equation are developed by step function

Critical flashover voltage mechanism and prediction of resin epoxy insulator on temperature changes

Nowadays, insulator material with resin epoxy has grown as alternative material or subsidizes the other insulator material such as porcelain and glass. But no many use this insulator in Indonesia with tropical climate, including Indonesia Electrical Company (PLN). One of reason is performance of this resin epoxy under condition have not good proofing, especially for outdoor with vary the temperature. Beside the advantages, resin epoxy insulator has a disadvantage. That is sensitive characteristics changes to temperature. This paper will examine the experiment results, temperature influence to flashover voltage on epoxy resin insulator with artificial light to vary the temperature and describe mechanism of critical flashover voltage on insulator surface with certain condition. This experiment is using clean insulator and polluted epoxy resin insulator. Pollutant weight level is determining based on IEC 815 standard. This paper is show prediction equation for critical flashover voltage with regression and polynomial interpolation methods base on experiment in laboratory. Experiment results shows that surface temperatures of epoxy resin insulator influence the value of flashover voltage. As the surface temperature increase, the flashover voltage will decrease. This is happened on each insulator conditions, clean condition or mineral contaminated condition.