直流调制改善交直流混联系统暂态稳定性的研究

RESEARCH ON IMPROVING TRANSIENT STABILITY OF AC/DC HYBRID SYSTEM BY HVDC MODULATION

文章研究了天广交直流混联系统中天广直流双侧频率功率调制对改善该混联系统暂态稳定性的作用,并做了基于实际系统运行方式的仿真实验,仿真结果表明,直流功率调制对减小系统第1个摇摆稳定峰值的效果比较明显;还基于典型两机系统的非线性直流调制控制器,构建了天广交直流混联系统的非线性直流调制控制器,并做了将其应用于实际系统的仿真实验。经综合比较得知,两种调制方式在改善系统的暂态稳定性方面的效果是相近的,且常规的双侧频率功率调制对电网运行的适应性更好。

Tian-Guang AC/DC hybrid system is the first AC and DC parallel operation system in China. Here, the effect of the improvement of transient stability of parallel operation system by power/frequency modulations at both sides of Tian-Guang hybrid system is researched, the simulation based on the operating modes of actual system is conducted. Simulation results show that it is efficient to reduce the amplitude of the first swing to make the system stable by HVDC power modulation. In addition, a nonlinear HVDC system modulation controller derived from this kind of controller for a typical two-machine power system is developed and simulation experiments are made for the purpose to apply the controller to actual system. Compositive comparisons indicate that the effects of improving transient stability of AC/DC hybrid system by two kinds of modulation modes are similar, but conventional dual power/frequency modulation at both sides possesses better adaptability to actual AC/DC hybrid system.