Research On Multiphysics Coupling Model Of Shore Power Cable And Calculation Method Of Real-time Ampacity In Complex Environment

With the implementation of the national "Belt and Road" strategy,China’s economic,trade and cultural exchanges with other countries in the world have become more frequent.Ships have severely polluted the environment of port cities,and shore power transmission technology can provide clean energy for ships arriving at ports.In order to meet the requirements of high power and grading load of the port,the ship-to-shore interactive power transmission uses high-voltage shore power cables.Those shore power cables are directly laid in the air,in a humid port,and exposed to sunlight.Equipment such as cranes and coils are required to connect shore power cable.It will be affected by the sea breeze and tide.The special working conditions of shore power cables accelerate the aging of insulation and reduce the ampacity of shore power cables.In addition,shore power cables are greatly affected by wind speed,water flow speed,solar radiation,etc.,and the calculation of temperature distribution and ampacity is more complicated.The IEC 60287 standards does not elaborate the calculation method of ampacity under the influence of wind,water and solar.There is no unified national or enterprise standard has been proposed.Therefore,it is necessary to establish an electromagnetic-thermal-flow-force multiphysics coupling model for shore power cables suitable for ports and investigate the calculation method of the temperature field and real-time ampacity of shore power cables in complex environments,to which provide a reference for the revision of ampacity calculation standards of shore power cable.Based on the above background and problems of shore power cables,the research content of this paper includes:1)An electromagnetic-thermal-fluid-force multiphysics coupling model for shore power cables was established and he coupling forms between each fields were analyzed,then using finite element simulation software to solve the problem.In order to verify the correctness,the results were compared with analytical results.2)Based on the simulation model,the effects of grounding mode of metal sheath,number of circuits and distance between circuits on the temperature were investgated.Then optimize the laying of shore power cables and study the influence of ambient temperature,wind speed,water flow speed and solar radiation on the temperature distribution of multi-circuit shore power cables3)Based on the heat balance equation of cable,a method for the real-time ampacity calculation of shore power cables based on Newton’s iteration is proposed,which has been realized by programming with MATLAB.This program are used to calculate the ampacity of shore power cables at different laying methods,ambient temperature,wind speed,water speed and solar radiation,easpecially considered the propagation characteristics of solar radiation in water,then studied the the hourly ampacity of shore power cables in different regions and seasons.In addition,the aging and tensile experiments of insulation were carried out.A method of calculating the ampacity of shore power cable based on the constraints of temperature and stress was proposed,then calculated the ampacity under different gap discharge energies.Finally,proposed some measures to increase the ampacity of the shore power cable.