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

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。

Power -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 overvohage 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 reduee the damage of power - frequency overvohage are presented. This research is helpful for promoting the security level of the isolated power grid in remote mountainous areas.