藏区孤网 QV 特性与过电压风险防控

Q － V Characteristic and Overvoltage Prevention for Isolated Power Grid in Tibetan Area of Sichuan Province

摘要:

工频过电压问题是威胁四川藏区偏远山区孤网运行时的主要问题。首先提出了适用于偏远山区电网孤网运 行的 N － 1 校核标准。在此基础上，以四川藏区典型结构的电网为例，从稳态 QV 特性以及考虑发电机低励限制的机 电暂态特性的角度，分析了偏远山区电网孤网运行时的过电压产生机理。最后，提出了降低偏远山区电网孤网运行 过电压风险的运行措施。所做研究对于提升偏远山区电网运行的安全稳定性具有指导性意义。

Abstract:

wer － frequency overvoltage is a major threat to the isolated power grid of remote mountainous areas in Tibetan area of Sichuan province． Firstly，a novel N － 1 check principle for isolated power grid in remote mountainous areas is proposed． Furthermore，the mechanism of power － frequency overvoltage in isolated power grid is analyzed based on steady － state Q － V model and electromechanical transient model with consideration of low excitation limit． Finally，the countermeasures to reduce the damage of power － frequency overvoltage are presented． This research is helpful for promoting the security level of the isolated power grid in remote mountainous areas．