Tie-Line Feasible Region Characterization Method for Nonlinear Regional Power System

With increasing demand for electricity and renewable energy, tie-line power exchanges among interconnected power networks facilitate the efficient utilization of power resources. Exact description of tie-line feasible region guarantees the security in power dispatching. However, because of the existence of nonlinear constraints, the tie-line feasible region is usually complex. This paper proposes an approximation method to characterize the original tie-line feasible region considering nonlinear constraints such as transmission capacity limit. A sufficient number of boundary points of the original nonlinear tie-line feasible region are obtained through the process of finding optimal solution by translating the facets, which is called multisegment boundary approximation method, then connect these boundary points to complete the approximation. Meanwhile, the accuracy of the approximation method is measured by Monte Carlo method. The calculation results demonstrate the validity of the multi-segment boundary approximation applied to nonlinear tie-line feasible region.