云广特高压直流对南方电网稳定性影响

Influence of Yun-Guang UHVDC Transmission System on Power System Stability of CSG

为研究云广特高压直流对南方电网稳定性的影响,利用PSD-BPA工具对受端五直流落点间相互影响、云广单、双极闭锁故障、孤岛运行方式、紧急直流功率提升和双侧频差调制等方面进行深入仿真研究,得出结论:(1)云广直流双极闭锁将引起功角和电压失稳,穗东换流站故障将引起多回直流不同程度地发生换相失败,且对北郊站换相电压跌落影响最大;(2)云广直流功率提升能有效提高电网暂态稳定性;(3)云广直流双侧频差调制能有效抑制小扰动下云粤间的功率振荡。

Some problems on Yun-Guang UHVDC transmission system,including inter-influence between five inverters,UHVDC block analysis,island operation mode analysis,UHVDC power run-up and DC bilateral frequency differential power modulation,were studied in the paper.PSD-BPA tool were used to analyze the influence on china southern power grid（CSG）power system stability,and the corresponding simulation results show that UHVDC bipolar block leads to an unstable system,and fault in Suidong inverter may leads other HVDC systems to communication failure and a biggest voltage drop in Beijiao inverter;and UHVDC power run-up function can well enhance transient stability by fault in paralleling AC or DC systems;and finally DC bilateral frequency differential power modulation can damp Yun-Guang inter-zone oscillation mode and improve transient stability.