Differential evolution algorithm for computation of dynamic ATC in deregulated power system

In restructured power system, determination of Available Transfer Capability (ATC) is an important issue. The ATC calculation is limited by system stability consideration. ATC calculated with dynamic stability limit is referred as Dynamic ATC (DATC). The Hopf bifurcation limit, associated with dynamic instability is considered in this paper as a limit for ATC calculation. In this paper, Differential Evolution Algorithm (DEA) is applied to obtain accurate Hopf bifurcation point for DATC calculation. Dynamic ATC is calculated for bilateral and multilateral transaction using the proposed approach. The static ATC is also calculated for finding the governing criteria for each transaction. In order to identify the severe lines for each transaction, stability based contingency screening is performed. Based on contingency screening index severe lines are ranked and for first five severe lines the DATC is calculated. The results are compared with a Step by Step algorithm. Simulation is done for three different load scenarios namely static, dynamic (Induction machine model) and ZIP load. The proposed approach is tested on New England 10 machine 39 bus system for various transactions using PSAT Tool. Test results show the accuracy of proposed approach.