Short Term Hydrothermal Scheduling with Prohibited Operating Zones

A modern power system consists of a large number of thermal and hydel plants connected at various load centers through a transmission network. An important objective in the operation of such a power system is to generate and transmit power to meet the system load demand at minimum fuel cost by an optimal mix of various types of plants. The study of the problem of optimum scheduling of power generation at various plants in a power system is of paramount importance, particularly where the hydel sources are scarce and high cost of thermal generation has to be relied upon to meet the power demand. The hydel resources being extremely limited, the worth of water is greatly increased. If optimum use is made of their limited resource in conjunction with the thermal sources, huge saving in fuel and the associated cost can be made (Ohishi 1991).