PERFORMANCE EVALUATION OF THE SECOND‐ORDER LOADFLOW CONTINGENCY METHODS

The superiority of the fast‐decoupled loadflow [FDLF] method is attributable to the underlying decoupling assumptions which, however, may not be valid for all modes of system operation. For example, during a restoration period following an emergency or in circumstances of unusual plant outages the assumptions of near nominal voltages and small phase angle differences may not be valid. Also for equivalencing methods, if large values of shunt admittance are contributed by the equivalent external networks, or if tap‐changing transformers are included, the FDLF method has shortcomings.