青藏直流投运后藏中电网稳定特性研究

藏中电网规模较小,网架结构相对较弱,青藏直流联网工程投运后给藏中电网的安全稳定运行带来诸多挑战,交直流系统稳定问题突出。从联网工程投运前藏中电网的电源特性、大机小网等固有特性出发,结合青藏直流联网以来青藏直流以及藏中电网运行中存在的各种稳定问题,深入分析了青藏直流投运后藏中电网的电源特性变化、稳定特性转化、虎曲线功率送出、直流换相失败、以及交直流影响等安全稳定问题。同时针对西藏电网的运行特性,分析并指出了青藏直流几个重要而特殊的安全稳定运行特性。

Research on the security and stability characteristics of Central Tibet power grid after Qinghai-Tibet HVDC putting into operation

Due to the small scale of the network and its weak grid structure, Qinghai-Tibet HVDC interconnection project will pose great challenges to the safe and stable operation of the Central Tibet power grid, especially to AC/DC system stability. Based on the inherent characteristics such as large-unit and small-grid, and features of the power sources and so on, and considering all the security and stability problems under operation of Central Tibet power grid and Qinghai-Tibet HVDC after the interconnection project put into operation, this paper makes a deep analysis of various changes in operating characteristics like the sources features, stability property, Huqu-line power transmission capability, DC commutation failure, and AC and DC interactions. Additionally, several significant and special operating requirements of Qinghai-Tibet HVDC are also analyzed and proposed on the premise of the safety and stability of Central Tibet power grid.