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It is possible to prevent collapse of the whole post-fault power system, which is in unstable condition, by determining the splitting boundary so as to calm down the system oscillation. A fast method of searching for the splitting boundary of power system controlled islanding is presented in this paper, the aim of which is to minimize the load-generation imbalance in each island. The method contains three phases, namely, defining the domain of each generator according to power flow tracing algorithm, determining an initial splitting boundary based on the grouping information of generators, and refining the initial one to get the final splitting boundary. A real-time searching program for power system splitting boundary was developed based on the method. Simulations on the IEEE 118-bus power system and a practical power system show that the proposed method is effective and fast.Index Terms-Controlled islanding, power flow tracing, power system, splitting boundary.

Article:Hu, D, Tian, W, Xie, F et al. (2 more authors) (2014) Effects of meridional sea surface temperature changes on stratospheric temperature and circulation. Advances in Atmospheric Sciences, 31 (4). 888 -900. ISSN 0256-1530 https://doi.org/10.1007/s00376-013-3152-6 eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. ABSTRACT Using a state-of-the-art chemistry-climate model, we analyzed the atmospheric responses to increases in sea surface temperature (SST). The results showed that increases in SST and the SST meridional gradient could intensify the subtropical westerly jets and significantly weaken the northern polar vortex. In the model runs, global uniform SST increases produced a more significant impact on the southern stratosphere than the northern stratosphere, while SST gradient increases produced a more significant impact on the northern stratosphere. The asymmetric responses of the northern and southern polar stratosphere to SST meridional gradient changes were found to be mainly due to different wave properties and transmissions in the northern and southern atmosphere. Although SST increases may give rise to stronger waves, the results showed that the effect of SST increases on the vertical propagation of tropospheric waves into the stratosphere will vary with height and latitude and be sensitive to SST meridional gradient changes. Both uniform and non-uniform SST increases accelerated the large-scale Brewer-Dobson circulation (BDC), but the gradient increases of SST between 60 • S and 60 • N resulted in younger mean age-of-air in the stratosphere and a larger increase in tropical upwelling, with a much higher tropopause than from a global uniform 1.0 K SST increase.

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