Recently several robust control designs have been proposed to the Load- Frequency Control (LFC) problem. However, the importance and difficulties in the selection of weighting functions of these approaches and the pole-zero cancellation phenomenon associated with it produces closed loop poles. Also the order of robust controllers is as high as the plant. This gives rise to complex structure of such controllers and reduces their applicability in industry. In addition conventional LFC systems that use classical or trial-and-error approaches to tune the PI controller parameters are more difficult and time-consuming to design. In this paper, a bisection search method is proposed to design well-tuned PI controller in a restructured power system based on the bilateral policy scheme. The new optimized solution has been applied to a 3-area restructured power system with possible contracted scenarios and the results evaluation shows the proposed method achieves good performance compared with recently powerful robust controllers
