A Distributed Power Transfer Limit Calculation Method for Multi-Area Interconnection Power Networks

Abstract

For multi-area interconnected power networks, each subarea may be operated by independent regulator, who oppose to open the access of private information such as network topology to the others. For this case, this study proposes a decomposition-coordination strategy to calculate power transfer limit (PTL) considering both saddle node bifurcation (SNB) and limit-induced bifurcation (LIB). The external coordination equations are derived based on the sensitivity analysis of boundary buses at tie-lines, to express the power exchange of subareas and the consistent boundary state variables. Power Flow (PF) results for each subarea system are separately calculated followed by the adjustment of tie-lines' PF injected into boundary buses according to the external coordination. Then the alternation between internal and external iterations, for which operators of subareas are not required to share private network information, could generate the same results as conventional PF that relies on the complete information. Moreover, an improved Continuation PF (CPF) model that includes the prediction of the PF of area tie-lines is proposed. The point of collapse (POC) method is employed to calculate PTL involving the SNB of the interconnected networks to improve the accuracy of the algorithm. Case studies demonstrate the effectiveness and reliability of the proposed method.