混联半波长交流输电线路最优配比及联网性能研究

Research on Optimal Proportion and Interconnection Performance of Hybrid Half-wavelength AC Transmission Line

随着大电网的发展及能源互联网概念的提出，半波长交流输电技术（HWACT）受到广泛关注，而架空线一电缆混联型半波长线路有望成为一种新的输电方式。为深入研究混联型半波长线路的特性，对混联型半波长线路的最优配比及联网特性进行了分析。首先，推导了单回输电线路的物理及数学半波长（HW）。然后，对混联型线路的半波长进行分析，提出了最优配比的概念及定义。根据半波长线路的特性构造最优化函数，实现对最优配比的求取。最后，利用2020年规划电网数据进行仿真实验，将混联型与常规型半波长输电系统进行对比。通过研究不同故障情况下的功角摆动曲线，对混联型半波长输电线路的联网性能进行评价。结果表明，按照最优配比原则组成的混联型半波长输电线路可有效提升系统阻尼，其构建的同步电网具有较强稳定性。

With the development of large power grid and the concept of global energy interconncction being proposed, half-wavelength alternating current transmission（HWACT） technology is increasingly concerned. The overhead lines combined with cable is expected to become a new way for power transmission. In order to further study the characteristics of hybrid HWACT line, we researched the optimal proportion and interconnection performance of hybrid HWACT line. Firstly, the mathematic and physical half-wavelengths（HWs） of a single line were derived. Subsequently, the HW of a hy- brid line was analyzed, and the concept and definition of optimal proportion were proposed. Then, the optimal function was constructed based on the characteristics of HWACT line so as to solve the value of optimal proportion. Finally, in or- der to compare the hybrid HWACT system with the conventional HWACT system, simulations were carried out based on the case of planning UHV power grids of the State Grid Corporation of China for the year 2020. The interconnection per- formances of the hybrid HWACT line was evaluated based on power-angle curves under different fault conditions. The results indicate that the hybrid HWACT line combined with the principle of optimal proportion helps to improve the sys- tem damping and build a strong synchronous power grid.