中文摘要：

风电和光伏发电等新能源在近年来得到了大规模快速发展,大规模开发、集中式送出是中国新能源发展的主要特征之一。目前中国西北等地风光新能源基地普遍通过特高压直流输电系统送至远方负荷中心,直流送端附近配套火电机组少,系统频率调节和无功/电压支撑能力弱,振荡问题突出,已经形成或即将形成弱同步支撑直流送端电网系统,运行控制难度大。文章从系统频率调节、无功/电压控制、次同步振荡机理与抑制等3个方面对大规模新能源接入弱同步支撑直流送端电网的运行控制技术国内外研究现状进行综述,分析已有研究存在的问题,尝试给出了后续研究建议和展望。

英文摘要：

Renewable energy sources such as wind power and photovoltaic（PV） power generation have been developed rapidly in recent years, and large-scale exploitation and centralized delivery are the main features of China＇s renewable energy development. At present, renewable energy bases in Northwest China are generally connected to the remote load centers through UHVDC transmission systems. Nevertheless, less thermal power units are installed at sending-end of UHVDC system, leading to a weak sending system requiring strong frequency regulation and reactive power/voltage controls. Additionally, oscillation problem becomes prominent and weakly-synchronized sending-end DC power grids are formed or under construction, causing great difficulty in operation and control of these power grids. In this paper, major technologies in system frequency regulation, reactive power/voltage control, sub-synchronous oscillation mechanism and its suppression for these weak sending system with external DC links are reviewed respectively. Existing problems are analyzed, and suggestions and prospective developments are proposed for future research.