A Transient Stability Constrained, Line-Flow-Based Fast Contingency Screening and Power Flow Evaluation

Abstract

A new methodology for a possible fast evaluation of a power flow is presented. The proposed method involves a transient stability constrained line-flow-based (LFB) fast contingency screening. This ‘direct’ method incorporates transient energy function (TEF) to carry out the evaluation of a power system. The proposed LFB method was tested on the WECC 9-bus, three machine, the IEEE 14-bus, five machine, and the IEEE 39-bus, ten machine systems. Results of the proposed LFB were compared with those obtained from the conventional Newton-Raphson (N-R) method. It was observed that the stable re-dispatch could be obtained by the LFB method within half the computation time as compared to the time required for the N-R method. Since the LFB method was based upon identification of the stable equilibrium points of the TEF, the proposed method appears to be inherently capable of delivering a stable power dispatch. In addition, a new index called critical energy performance index (CEPI) has been introduced to indicate the level of stability and to assist in the decisions related to the re-dispatch.