适用高比例新能源系统广域消纳的输电技术研究综述

针对特高压直流输送新能源存在的频率稳定、电压稳定和连锁反应等问题，本文分析研究了几种研究较多、有可能在我国纳入规划的技术的原理、应用场景和案例。从替代技术角度，提出了半波长交流输电替代特高压直流输电和构建立体电网的应用场景；分析了柔性直流利于组网的特点，提出了用于新能源接入及构建直流电网的应用场景。以单位容量年费用法比较了两类替代技术的经济性，得出了柔性直流输电技术更优的结论，研究了其经济输电范围。从辅助技术角度，分析了虚拟同步机改善新能源调频特性，并提出可应用于新能源高渗透率送受端电网的场景；分析了调相机的动态无功调节能力，并提出了可应用于新能源基地的输电系统。以四类替代技术及辅助技术的发展轨迹及我国电网发展历程、未来形态的变化，讨论、预测未来四类技术的发展趋势及其对未来电网形态的影响。

Transmission technologies adapting to power systems with widely-consumed high-proportion renewable energy

The frequency unstability, voltage unstability and chain reactions could occur on renewable energy transmitted by UHV DC lines. Therefore, the theory, application and cases of technologies which are drasticly researched and could be utilized in planning in China are analyzed. From the angle of an alternative technology, the traits of half-wave-length transmission that could act as a substitution of UHV DC transmission and can construct three-dimensional grid are put forward. Flexible DC transmission has preponderances such as practicability to organize a DC network, which could be utilized in the scenes to admit renewable energy and establish a DC network. The economy of two alternative technologies is compared basing on the principle of annual fee per unit capacity, drawing a conclusion that flexible DC transmission costs less. Moreover, its economical transmission range is researched. The characteristics of frequency modulation of virtual synchronous machine for new energy are analyzed as an assistive technology. Its application in new energy high permeability sending or receiving end power grid is presented. The dynamic reactive modification capacity of synchronous condenser is analyzed. Its application in transmission systems of new energy base is presented. On the basis of the trajectory of four alternative and assistive technologies and the variation of the pattern of power system in the history and anticipated, the tendency of development of four technologies and their influences on the shape of power system will be discussed and forecasted.