TRANSIENT SECURITY AND ECONOMIC DISPATCH

Security assessment requires that the power system must be capabable of suitably – supplying the connected loads in both steady state and contingency conditions. In economic dispatch, normal security constraints for bus voltages, active power of generators, and line flows are specified. However, the results of this dispatch may give rise to an increase in the vulnerability of some lines. For such a situation, vulnerable line becomes transiently weak and line – or generator – outage may occur during contingency. Vulnerability indices of line – outsets belonging to some selected contingencies, can be included in the economic dispatch program. The results obtained clarify that a better choice of the weighting factors of the augmented cost function, gives rise to substantial improvement of transient stability of the power system while keeping the total generation cost at a minimum. The DFP (Davidon- Flitcher- powell) - method used, had proved to be a highly convergent economic dispatch algorithm