A Novel Approach of Rescheduling the Critical Generators for a New Available Transfer Capability Determination

The transition to a deregulated electric power system industry has created a highly competitive electricity market with immense power transfer activity performed between the market participants. A poorly-damped oscillation of small-signal instability is usually imminent during a stress power system condition attributed by the base case power transfer or available transfer capability (ATC) compounded with an outage of critical line. The contingency ranking by means of lowest damping ratio is introduced so that execution of the most critical line outage will incite to a poorly-damped oscillation during the base case ATC. The rescheduling of few critical generators determined by using the normalized participation factor is presented in this paper as a novel, non-intricate and cost-effective solution for estimating a new value of ATC while ensuring a secure power system operating condition. Sturdiness of the proposed method is verified through comparison with the weighted-average sensitivity of stability index required for rescheduling the critical generators performed in a case study of 39-bus New England system. Comparative study on the results of cost minimization in generators rescheduling has also been done based on the critical generators selected by the two methods.