微机静止无功补偿系统及其通信实现

详细介绍了在SVC中实现DSP和PC机之间的异步串行通信,对在VisualC++.net环境下使用MSComm控件开发程序时的难点作了详细论述,并给出了程序运行结果。     

浅谈港口供电网自动化系统

以天津港电力公司自动化系统为例,介绍了电网自动化系统的组成,主站系统和变电站系统的技术特点和供电网天津港自动化系统的作用。     

基于物元贝叶斯网络的舰船战损评估模型研究

分析了舰船战场损伤评估过程,从而得到舰船战场损伤评估的基本流程。分析了过去关于舰船战场损伤评估研究的缺陷和不足。在物元理论和贝叶斯网络理论分析的基础上,建立了节点物元模型和物元贝叶斯网络模型,进而提出了物元贝叶斯网络理论。根据舰船战场损伤评估的特点,分析了建立舰船战场损伤评估模型的步骤及相关工作,并以某舰艇操船系统为例,建立了操船系统损伤评估的物元贝叶斯网络模型。应用示例表明了所提理论的可行性、适用性和可操性。     

Load effects on vessel-shaped fish cage steel structures,nets and connectors considering the effects of diffraction and radiation waves under irregular waves

Vessel-shaped fish cages are mainly composed of a large floating body, aquaculture nets and a number of steel frames. Due to the large scale of vessel-shaped fish cages, the velocity field induced by the diffraction waves and radiation waves cannot be ignored in the calculation of the loads on the net and steel frames. In turn, the loads can affect the wave-induced response of the floating body and hence the radiation waves as well as the sectional forces. In this paper, a novel method is proposed to consider the coupling effect. First, considering the irregular waves in short-term periods, the global response of the floating body is calculated in the time domain by the state-space method based on potential flow theory. Meanwhile, the velocity field considering the influence of the floating body is built according to the velocity transfer function. Then, the Morison formula is used to calculate the loads on the nets and the steel frames. Finally, the coupling achieved through numerical iterations is considered in the calculation of the twine tension, load effect of connector and the global cross-section under irregular waves. It is found that the diffraction and radiation waves make a significant difference in the twine tension and connector load effect.     

Towards a holistic digital twin solution for real-time monitoring of aquaculture net cage systems

Digital twins and relevant concepts are being applied in a wide variety of ways, and they are of most use when an actual real-world physical system or process (a physical twin) is changing over time and when measurement data correlated with this change can be captured. In this work, a digital twin model was implemented for real-time monitoring of aquaculture net cage systems, which is notoriously challenging because of several difficult-to-measure properties, such as forces on and deformation of the flexible netting structures, waves and flow field alterations around the cage and complex stiffness behaviour of the mooring elements made by fibre ropes. These properties were set to be adaptable according to the resultant outputs, such as cage responses and mooring loads that were continuously compared with the measurement data obtained from remote monitoring sensors. In this way, real-time sensor data were assimilated into the numerical simulation model for representing the actual net cage system. No dedicated sensors were used for fish monitoring, but the fish behavioural responses to current, wave and cage deformation were modelled according to relevant field observational data. A wireless sensor network has also been tested for the digital twin implementation, which was found to be suitable for practical uses in fish farms.