Genetic algorithm based real-time rating for short-time thermalcapacity of duct installed power cables

摘要

Japanese utilities have promoted research to use existingequipment more effectively. Until now, Neher's equations have been usedto calculate the short-time thermal capacity of power cables. However,in order to use existing power cables more effectively, detailedcalculations which consider time-varying thermal resistance andcapacitance of the surrounding soil are necessary. For duct-installedpower cables, duct temperatures can be measured by newly developedoptical fiber temperature sensors. In this paper we propose a method tocalculate the short-time thermal capacity of duct-installed powercables. The proposed algorithm is based on the estimation of the thermalresistance and capacitance of the surrounding soil using continuouslymeasured duct temperatures. In this algorithm, a genetic algorithm isemployed to estimate this resistance and capacitance accurately. Theeffectiveness of the proposed algorithm is demonstrated using theexperimental data. It is shown that applying the proposed methodimproves the short-time thermal capacity of duct-installed power cablesconsiderably