Optimal load curtailment as a bi-criteria program

The primary aim for the deregulation of the power industry has been to lower the energy prices for the customer. On several occasions, it has been observed that energy prices have increased dramatically, and a primary reason for this has been traced to congestion in the transmission network. Re-dispatching generation or curtailing interruptible loads are some of the options that the ISO/utility have in order to alleviate this problem. This paper presents a methodology to optimally curtail load, to maximize the stability margin, in the event of a shortage of generation. Iterative and one-step solution procedures are proposed and compared to bring out the merits of each. Additionally, a bi-criteria programming model is also proposed that seeks to optimize two objectives-maximizing the security margin and minimizing the cost incurred in the process simultaneously. Results are presented for two standard test systems. (C) 2003 Elsevier Science B.V. All rights reserved.