Incorporating dynamic security into market dispatch using accurate transient stability constraints

This paper proposes the inclusion of transient stability constraints in generation dispatch algorithms used in electricity markets to ensure dynamic security. The proposed security constraint is derived by applying a non-linear surface fitting technique to a database generated off-line. The technique used has two key features that enables very fast computation of an accurate transient stability constraint. One feature is that it uses a linear estimation technique to estimate a non-linear function by means of a non-linear transformation. The second important feature is that it employs an implicit technique to gain significant reduction in computing burden. The security constraints derived for each credible contingency can be used in an Optimal Power Flow program for market clearance. The effectiveness and efficiency of the proposed method is demonstrated using the New England 39 bus system and a larger power system with 470 buses.