Real time transfer limit calculations

This paper presents an approach for implementing the real time transfer limit calculation (RTTLC) of the interconnected power systems in an energy management system (EMS). RTTLC evaluates MW transfer limits over a set of predefined transfer interfaces without power system security violations such as thermal overloads, bus voltage limit/voltage drop violations and voltage collapse. The network model, base case solution and contingencies used by RTTLC are provided by the state estimator and the security analysis. The continuation power flow (CPF) is used as an engine for the RTTLC to account for transmission branch power flow constraints, bus voltage drop limits, bus voltage limits and voltage stability. The test results for a practical power system model are presented.