振荡中心ucosφ定位校正及广域失步解列控制

Correction of Oscillation Center Location by Ucosφ and Wide Area Out-of-step Splitting Control

受新能源装机规模持续增长、交直流混联结构新特征日益凸显等因素影响,大电网受扰行为愈趋复杂,保障电网安全对第三道防线失步解列控制的动作可靠性、精准性和有序性提出了更高要求。文章首先分析了基于就地量测信息的ucosφ失步解列控制的原理及其应用局限性;研究了ucosφ与振荡中心之间的关系并定义了振荡中心定位系数ζ。在此基础上,提出了“分散就地判别、集中协同决策”的广域失步解列控制策略。交直流混联大电网仿真结果表明,所提策略能够适应多机群相继失步的复杂大电网动态行为,能够准确识别与失步机群相对应的网间割集,并实现割集中各支路统一有序解列。

Influenced by the continuous growth of new energy installation scale and the increasingly prominent characteristics of AC-DC hybrid structure, the disturbance to the large power grid is becoming more and more complex. To ensure the safety of the power grid, higher requirements are put forward for the reliability, accuracy and orderliness of the out-of-step splitting control in the third-line defense. Firstly, this paper analyzes the principle and application limitation of the out-of-step splitting control by ucosφ based on local measurement information, studies the relationship and errors between the ucosφ and the oscillation center, and defines the location coefficient ζ of oscillation center. On this basis, the criteria of branch splitting and the control strategy of multi-branch wide area cooperative out-of-step splitting are proposed. The simulation results of the AC and HVDC hybrid power grid show that the proposed strategy can adapt to the complex dynamic behavior of the large power grid in which the multiple generator clusters lose synchronization sequentially. And it is able to accurately identify the cutset corresponding to the out-of-step generator cluster, and realize the unified and orderly splitting of each branch in the cutset.