Different strategies of interruptible load contracts implemented in reliability constrained unit commitment

In restructured power markets, participants try to optimize their profit/cost. In this market driven environment, by increasing fuel cost, ISO tries to make new opportunities and facilities to minimize power prices and consequently increase social welfare. One of these opportunities is interruptible load that traditionally used to reduce overloads and maintain network security. In restructured power exchange, an interruptible load contract may contain many details and limitations. In this paper, ISO offers flexible contract in which load limitation are considered. Therefore contract is compatible with load situations. Hence, three different interruptible loads with different limits and different prices were considered in unit commitment program for day-ahead market. In order to maintain security, probabilistic reliability constraints are used. Finally, the effect of different interruptible loads and reliability constraints on operational cost are analyzed.