N-2组合故障集的暂态功角稳定在线快速评估

大电网中N-2组合故障数目巨大,若对每个组合故障分别进行暂态功角稳定评估,难以满足在线评估的时间要求。基于N-2组合故障中第一个元件故障的暂态功角稳定在线评估结果(裕度和主导群发电机的参与因子),结合第一个元件故障的暂态功角稳定主导群中发电机的有功功率对第二个开断元件有功功率的灵敏度,计算出N-2组合故障的暂态功角稳定严重程度排序指标。通过优先对排序在前位的组合故障进行基于详细模型时域仿真的暂态功角稳定量化评估,直至排序号连续的多个组合故障的暂态功角稳定裕度都大于0,则直接判定排序在其后的所有组合故障均是暂态功角稳定的,从而满足N-2组合故障集暂态功角稳定在线评估对计算速度的要求。实际电网算例验证了该方法的有效性。

Online fast transient angle stability assessment of N-2 contingency set

The total number of N-2 faulty element combinations is huge in large scale power system. Transient angle stability analysis for all N-2 contingencies cannot be finished in given time required by online assessment. The index for contingency severity ranking is proposed to filter out slight cases. The index is calculated based on the stability margins and dynamic modes of the N-1 contingency and sensitivity analysis of another faulty element to generators in the critical cluster. Contingencies with larger index are selected for detailed transient angle stability assessment in order. If the transient angle stability margins of multiple sequential contingencies are greater than 0, subsequent contingencies can be judged stable. Real engineering applications in actual power grid have fully confirmed the validity and practicability of this method.