特高压直流输电导线经济截面选择研究

Research on Economic Optimization of Section Areas of Conductors for UHVDC Projects

根据中国电力需求增长趋势和能源分布格局,中国未来将建设30项特高压直流输电工程。而输电线路导线总截面及分裂型式的选择,是决定直流输电工程在全寿命周期内获得良好经济效益的重要因素。从最基本的累计净现值公式着手,综合考虑建设投资和运行损耗两个方面,重点研究直流输电工程的线路损耗小时、上网电价、线路工程造价等因素对导线经济电流密度的影响,整理推导出直流输电导线经济电流密度的计算公式。通过收集大量工程建设和运行中实际数据,对已建成的直流工程进行验证计算。结合当前建设成本和电价水平,提出对于长期重载直流输电系统,输电导线经济电流密度应在0.6A/mm2左右。

To meet the demand of electric power growth trend and the energy distribution pattern in China, 30 ultra high voltage （UHV） DC transmission projects in China will be built. Selection of total cross-section and split type for transmission line conductor is an important factor in obtaining good economic benefits during the entire life-cycle of DC power transmission projects. Starting from the accumulative net present value formula, this paper considered two aspects of construction investment and operation loss, studied the impact of line loss hours, on-grid power tariff, line construction cost of DC power transmission projects on conductor economic current density, and derived the calculation formulas of DC power transmission conductor economic current density. By collecting a large number of actual data about construction and operation of projects, completed HVDC projects were calculated. Combining with current construction cost and the price level, the paper proposed that transmission conductor economic current density should be around 0.6 A/mm2 for long-term overloaded DC transmission systems.