Studied in this paper is free vibration of a long span pipeline with nonlinearities taken into account. The pipeline sags under gravity and takes the shape of a plane curve. Vibration in the plane and out of the plane...Studied in this paper is free vibration of a long span pipeline with nonlinearities taken into account. The pipeline sags under gravity and takes the shape of a plane curve. Vibration in the plane and out of the plane is regarded as small motions about the large static deflection. Manifestations of nonlinearities such as amplitude-dependent frequencies and internal resonance are investigated.展开更多
现有的电压暂降严重程度评估方法大多仅考虑暂降幅值和持续时间等技术指标,较少涉及对经济指标的研究,导致评估结果无法体现不同敏感用户对于电压暂降治理的差异化需求。针对此问题,提出一种计及经济损失指标的敏感用户电压暂降严重程...现有的电压暂降严重程度评估方法大多仅考虑暂降幅值和持续时间等技术指标,较少涉及对经济指标的研究,导致评估结果无法体现不同敏感用户对于电压暂降治理的差异化需求。针对此问题,提出一种计及经济损失指标的敏感用户电压暂降严重程度评估方法。在电压暂降幅值和持续时间两个指标的基础上,引入电压暂降经济损失指标,建立电压暂降严重程度评估指标体系。基于层次分析法与熵权法的组合赋权法计算各指标权重,进而结合TOPSIS(technique for order preference by similarity to an ideal solution,TOPSIS)法和灰色评价法得到各用户电压暂降严重程度评价排序。仿真结果表明,通过所提方法得到的评估结果能凸显不同敏感用户的差异化需求,从而为确定电压暂降治理的先后顺序及具体措施提供更科学的参考。展开更多
文摘Studied in this paper is free vibration of a long span pipeline with nonlinearities taken into account. The pipeline sags under gravity and takes the shape of a plane curve. Vibration in the plane and out of the plane is regarded as small motions about the large static deflection. Manifestations of nonlinearities such as amplitude-dependent frequencies and internal resonance are investigated.
文摘现有的电压暂降严重程度评估方法大多仅考虑暂降幅值和持续时间等技术指标,较少涉及对经济指标的研究,导致评估结果无法体现不同敏感用户对于电压暂降治理的差异化需求。针对此问题,提出一种计及经济损失指标的敏感用户电压暂降严重程度评估方法。在电压暂降幅值和持续时间两个指标的基础上,引入电压暂降经济损失指标,建立电压暂降严重程度评估指标体系。基于层次分析法与熵权法的组合赋权法计算各指标权重,进而结合TOPSIS(technique for order preference by similarity to an ideal solution,TOPSIS)法和灰色评价法得到各用户电压暂降严重程度评价排序。仿真结果表明,通过所提方法得到的评估结果能凸显不同敏感用户的差异化需求,从而为确定电压暂降治理的先后顺序及具体措施提供更科学的参考。