风光火打捆高压直流外送下送端电网高频切机方案适应性研究

Adaption Studies on High-frequency Generator-tripping Strategy for Sending System of Wind-PV-thermal-bundled Power Transmitted by HVDC

针对风光火打捆高压直流外送下送端电网的高频问题,分析了既有高频切机方案的适应性,并提出了改进方案。首先,理论分析了不同类型电源的动态频率特性;其次,基于我国西部某省级电网,提出了用于高频切机方案适应性分析的多种典型方式,并仿真对比了不同运行方式下,含风光火的省级送端电网与西北主网解列后的频率特性变化;最后,分析了既有的高频切机方案不适应大规模风光接入的问题所在,对原始高频切机方案进行了改进,提出了"首轮切风光后续轮切火电"的高频切机方案,结合多种典型运行方式进行了仿真校核,验证所提改进方案的适应性。

On the high-frequency issue for sending system of wind-PV-thermal-bundled power transmitted by HVDC,the adaptability of existing high-frequency generator tripping strategy is analyzed,and then the improvement strategy is proposed.Firstly,the impacts of wind and PV power integration on system dynamic frequency characteristics are analyzed theoretically.Secondly,based on a provincial grid in the west of China,a variety of typical operation modes are presented to study the adaptability of existing high-frequency generator tripping strategy.Furthermore,some simulation comparisons on the provincial frequency characteristics after system separation are made under different operation modes.Finally,the reason that the existing strategy is not adaptive to power system integrated with large-scale wind power and photovoltaic is analyzed.Meanwhile,the improvement strategy of＂first round to trip wind and PV power,and the follow-up rounds to trip thermal power＂is proposed.The effectiveness of the proposed strategy under different typical operation modes is verified,and its adaptability is proved.