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Analysis Of Cable Ampacity Influencing Factors And Study On The Optimization Method Of Cable Laying Scheme

Posted on:2011-12-20Degree:MasterType:Thesis
Country:ChinaCandidate:R G ChenFull Text:PDF
GTID:2132360308458984Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
Power cable is the key power transmission equipments, it is widely applied in the power system, its laying mode and laying environment are complex increasingly. For the traditional cable ampacity calculation method, the calculation parameters are based on the recommended values of IEC-60287 standard, which have a greater difference from the field operation values, leading to the theoretical value and the actual value of the cable ampacity have a great deviation. Meanwhile, a variety of laying ways are used for the cable installation, such as directly buried laying, cable duct laying, tunnel laying, pipe laying and so on, by which the economy and reliability of the cable operation are affected directly. Therefore, calculating the cable ampacity accurately according to the complex external environment and determining an optimal laying program are very important to improve the cable'capacity utilization rate, and to guarantee the safe operation of the cable.Aiming at the insufficient of the traditional ampacity calculation method that the laying environment is not simulated accurately, key issues such as the calculation of power cable ampacity, analysis of the ampacity influencing factors and optimization of the cable laying ways were studied throughly in the paper:Firstly, in order to simulate the cable laying environment accurately, and avoid conducting a large number of experimental studies using the traditional methods, based on the principle of heat transfer theory and finite element method (FEM), a model of cable ampacity calculation was constructed by adopting the method of finite element divided automatically in the paper. The laying condition and the environment condition of the cables were considered in the model, and according to the variation of the laying condition and the surrounding condition, the relative parameters of the model can be modified conveniently, then the temperature distribution of the different cable layers and the surrounding area can be analyzed.Secondly, in accordance with the structural parameters, the loss parameters of cables and the physical parameters of the laying area, a calculation method based on the dichotomy was presented. By analying the example of duct laying cables, the impact law of the different influential factors on the cable ampacity was summarized, which provided significant theoretical basis for optimizing the cable laying ways .Thirdly, aiming at the actual situation that the cable laying methods are diverse and there are no unified decision schemes, a expert evaluation index system was presented in the paper based on considering the various influential factors of decision scheme comprehensively, and a cable laying scheme optimization index calculation model was established. In the model, different expert's advices were treated by introducing the concept of coordination degree, and the index weight was determined by applying the trapezoidal fuzzy number.Finally, based on the determined cable laying ways, a method that can improve the cable ampacity by optimizing the cable running road was presented, and the methods that can improve ampacity of the cables laid in soil directly,trench,tunnel and pipe were proposed respectively.
Keywords/Search Tags:power cable, ampacity, influential fators, laying mode, optimizing
PDF Full Text Request
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