海上风电送出交流高压单芯电缆并联通流特性研究

Research on Current-carrying Characteristics of Parallel Connected AC High-voltage Single-core Cable Applied in Offshore Wind Power Transmission

由于海上风电送出规模的增大,需采用多根电缆并联进行输电。多回并联电缆平行敷设时,由于电磁耦合的作用,电缆间阻抗不一致导致同相并联电缆间电流分配不均匀,造成电缆载流量得不到充分利用,严重时甚至会引起电缆过热损坏,因此,有必要对并联电缆的通流特性进行研究。首先,研究了电缆阻抗参数的计算方法,建立了电缆并联运行的PSCAD/EMTDC仿真模型;然后,计算了8种电缆布置方式下并联电缆的分流情况,并对结果进行了分析对比,给出了最优的布置方式;最后研究了分流不均匀系数的影响因素,并针对工程实例进行了计算和优化,优化后电缆分流不均匀现象得到明显改善。

Due to the increase of the scale of offshore wind power transmission,multiple cables are needed for parallel transmission.When multiple cables are laid in parallel,due to the effect of electromagnetic coupling,the impedance between each cable is inconsistent,resulting in uneven distribution of current in the same parallel cables,which will lead to insufficient utilization of current-carrying capacity of the cables,and even cause cable overheating damage in serious cases.Therefore,it is necessary to study the current-carrying characteristics of parallel cable.The calculation method of cable impedance parameters is studied,the simulation model with PSCAD/EMTDC is established for parallel operation of cables,the current distribution coefficients of parallel cable under eight cable layout modes are calculated,the results are analyzed and compared,and the optimal layout mode is given.The influencing factors for nonuniform coefficient of current distribution are studied,and the calculation and optimization are carried out for an actual project,and the uneven distribution of current is improved significantly after optimization.