A DYNAMIC APPROACH FOR TRANSMISSION MANAGEMENT THROUGH A CONTRACT CURTAILMENT STRATEGY

In this paper, a contract curtailment proce- dure for the management of power systems in a deregu- lated environment is presented. A method to evaluate corrections on power exchanges in bilateral contracts is proposed in order to guarantee the static and dynamic security. The cost of curtailment for each transaction is evaluated concurrently to the solution of a dynamic opti- mization problem. The procedure has been implemented on an actual and detailed representation of the Italian national grid. Test results are presented. security constraints are integrated in the same formula- tion. The distribution of curtailment among transactions is strongly influenced by the formulation of objective functions and other features. In (5-6), curtailment de- pends on the willingness-to-pay of each customer, whereas in the definition of rules for the Transmission Loading Relief for the WSCC (7), some LIFO priority lists are taken into account. In this paper, the proposed contract curtailment strat- egy is based on the sensitivity of each transaction to the static and dynamic performances of the system. Moreo- ver, the objective function is related to the firmness of transactions. This feature can be exploited by ISO to minimize curtailment costs, taking into account the presence of firm and interruptible loads. The procedure has been implemented on an actual and detailed representation of the Italian transmission system. Test results are presented.