Sensitivity-Based Approach for Optimal Power Flow with Transient Stability Constraints

This paper presents a new method for optimal power flow with transient stability constraints (OTS). Based on the theory of projection energy function (PEF), the variation characteristic of minimum projection kinetic energy (PKE) in post-fault duration against generation of severely disturbed generators has been studied. The trajectory sensitivity mapping technique is utilized to evaluate the gradient of minimum PKE with respect to active power output of generators. Using the gradient, a new approach for stability-constrained generation limit assessment is proposed. Then the stability constraints represented by differential equation are converted into inequality constraints of active power outputs of generators. Thus, the OTS problem could be solved by traditional optimal power flow (OPF) method. The proposed approach can deal with multi-contingencies simultaneously. Case study on the 10-generator New England test power system is given to verify the efficiency of the method.