Probabilistic Operation of Electric Power Systems Considering Environmental Constraint (Part 3)* -A Method Considering Transmission Capacity-

We have previously reported an optimum operation decision method which would be economical and satisfy environmental constraint. In this report, we consider the constraints of transmission capacity. Using the same method used for environmental constraint, we can also satisfy the transmission capacity constraints. But if we use this method, we must be prepared for the increased kinds of the numbers of Lagrange’s multipliers. The decision of these multipliers generally becomes increasingly difficult as the numbers increase. In this proposed method, only two Lagrange’s multipliers are used. That is to say, as a first step we consider only two constraints : the power supply and demand balance constraint and the environmental constraint. The result obtained from the above step is modified to satisfy the transmission capacity constraints and also to minimize the increase in operating costs. In the first half of this report，we consider the deterministic system load. In the latter half, we consider the case in which a system load varies probabilistically. Finally we show the results of model system simulations