综合考虑中性点接地方式和网架结构的配电网供电可靠性的评估

摘要:本文通过综合考虑不同中性点接地方式下发生单相接地故障时线路跳闸的原因,建立了不同中性点接地方式下线路故障可靠性概率模型;然后,根据三种典型的配电网网架结构的特点,考虑网架结构的不同会对用户供电产生的影响;最后,建立综合考虑中性点接地方式和网架结构的配电网可靠性评估模型,以树干式和环式配电网为例,进行计算,得出两种典型的配电网接线在不同的中性点接地方式下的供电可靠性,同时客观评价了两种中性点接地方式下配电网供电可靠性水平。     

Study on the trajectory prediction curves of supercavitating vehicle

In order to understand the laws of motion for supercavitating vehicle better, simplified equations for longitudinal motion of supercavitating vehicle were derived. Then the corresponding simulation software for trajectory of supercavitating vehicle was programmed, by which the theoretical predicted trajectories of the supercavitating vehicle at different velocities were obtained. It was found that the predicted trajectories at low speed and without cavitation on the vehicle in theory agreed well with those in experiments, and the theoretical predicted trajectories at high speed and with supercavity on the vehicle correctly reflected the motion laws of the supercavitating vehicle. The influences of various parameters of cavitator and rudder on the underwater trajectory were compared and analyzed, which can provide a guide for the design of hydrodynamic distribution and gross parameters of the supercavitating weapons.