直流换流阀海上运输动力响应分析方法研究

Dynamic response analysis method for DC converter valves in marine transportation

大型变电设备在驳船实际运输中,在风浪、潮流等外部作用下经常发生不同程度的损坏,研究最不利环境下设备的动力响应,对运输设备的安全性进行探讨是必要的。为此,以某海上直流换流阀塔为研究对象,基于其自身振动特性研究其在海上运输的动力响应,针对海上运输环境复杂多变、研究工况多、时频分析计算周期较长,在功率谱分析的基础上提出了基于拟静力的分析方法。结果表明:当波浪频率与结构基频比值小于0.15时,可用拟静力分析方法直接得到结构应力响应,位移响应则需对拟静力结果放大1.30倍修正以保证安全;当波浪频率与结构基频比值接近1.00时,结构响应的放大系数和频率比呈线性相关。该研究为设备的海上运输安全评估及加固提供依据。

In the actual transportation of large power transformer equipments,different degrees of damages often occur under the external actions of wind and wave,so it is necessary to study the dynamic responses of the equipments under the most unfavorable environment and discuss the safety of the transported equipments.Therefore,taking an offshore direct current converter valve tower as the research object,the dynamic response of the valve in sea transportation was studied based on its own vibration characteristics.In view of the complex and varied marine transportation environment,many working conditions for research,and the long calculation period of time-frequency analysis,a pseudo-static analysis method was proposed on the basis of the power spectrum analysis.The results show that when the ratio of wave frequency to fundamental frequency is less than 0.15,the structural stress response can be obtained directly by the pseudo-static method,and the corresponding displacement response should be modified to be 1.30 times of the pseudo-static value for safety.When the ratio of wave frequency to fundamental frequency of structure is close to 1.00,the amplification correction factor of the structural response is linearly correlated with the frequency ratio.The research provides a basis for the safety assessment and reinforcement of the equipments in marine transportation.