国际海事组织船舶能效提案及其影响综述

This paper presents a review of the different International Maritime Organization(IMO)initiatives to improve the ship energy efficiency of new and existing ships,which is considered one of the essential tasks to reduce Greenhouse Gas(GHG)in the maritime industry.First,the IMO effort and initiatives and the different indices suggested by the IMO are presented till the last version of the Marine Environment Protection Committee(MEPC),showing the effect of different technologies on reducing the level of indices and the suggested improvement of the terms of indices in the next years.Second,the short-and long-term strategies suggested by the IMO are presented,showing that the effect of indices will be noticed in the short term,while the new fuels will show a significant improvement in the long term.Finally,several examples of cooperation between the different organizations are presented,showing that transferring knowledge and experience will significantly impact the maritime industry and thus lead to the concept of green ships in the near future.This paper shows that the combination of different solutions,the cooperation between stakeholders and the sharing of the data and information are important to achieve the required goal.

Time-domain Differential Protection Based on Operating and Restraining Trajectory Indices for Lines Connecting Battery Storage Energy Stations

Battery energy storage stations(BESSs)pose sever-al challenges for both phasor-based differential protection and the newly-proposed time-domain differential protection.These challenges include low sensitivity and even rejection.Besides,the negative impact of various nonideal conditions,including current transformer(CT)saturation,errors,and outliers,on the security of differential protection remains an important problem.Motivated by the aforementioned issues,this study accounts for the trajectory distribution discrepancy on Cartesian plane under various conditions and proposes a time-domain differential protection method.In this paper,the trajectory formed by operating and restraining current samples is devel-oped.Subsequently,after considering different operating states,the fault severity levels,and nonideal conditions,the variances in trajectory distribution between internal and external faults are extensively analyzed.On this basis,the Cartesian plane is divided into operating,uncertainty,and restraining zones.Further,the operating and restraining trajectory indices are meticu-lously designed and a protection criterion based on these indices is formed to accurately separate internal faults from other events,unaffected by CT saturation,errors,and outliers.The exceptional performance of the proposed protection method is extensively validated through PSCAD simulations and a hard-ware-in-the-loop testing platform.Regarding the dependability,sensitivity,and security,the proposed protection method outper-forms three state-of-the-art differential protection methods.

Construction and Upgrade of Urban Power Grids:Achievements and Tasks

The significant achievements in construction and upgrade of China’s urban grids in the past two years and more are enumerated with respect to scale of grids, configuration of medium-and high-voltage grids, technical and localizing level of equipment, as well as social and economic benefits. At the same time, the new tasks for the year 2001 is put forth for volume of investment to be completed, projects progressing and operating benefit indexes, etc.