Measurements of Synchronous Machine Parameters Under Operating Condition

A practical method for deriving operational impedances from on load tests is proposed. This method differs from well-known frequency response methods from stator or rotor circuit [3-5]. The operational impedances are calculated from the data of small perturbations of the generator voltage, current and rotor angle during system disturbances using Laplace transforms. They include the saturation effect and are suited for dynamic stability studies.