HyungSeon Oh

2papers

2 Papers

SYJun 9, 2017
Situational Awareness with PMUs and SCADA

HyungSeon Oh

Phasor measurement units (PMUs) are integrated to the transmission networks under the smart grid umbrella. The observability of PMUs is geographically limited due to their high cost in integration. The measurements of PMUs can be complemented by those from widely installed supervisory control and data acquisition (SCADA) to enhance the situational awareness. This paper proposes a new state estimation method that simultaneously integrate both measurements, and show an outstanding performance.

NAJun 2, 2017
Multiple-rank Modification of Symmetric Eigenvalue Problem

HyungSeon Oh, Zhe Hu

Rank-1 modifications in k-times (k > 1) often are performed to achieve rank-k modification. We propose a rank- k modification for enhancing computational efficiency. As the first step towards a rank- k modification, an algorithm to perform rank-2 modification is proposed and tested. The computation cost of our proposed algorithm is in O(n^1.5). We also propose a general rank- k update algorithm based upon the modified Sturm Theorem, and compare our results from those of the direct eigenvalue decomposition and of a perturbation method.