Two Novel Methods for Parameter Identification of Synchronous Machine Using DC-Decay Test with Rotor in Arbitrary Position

The goal of this paper is to propose and validate standstill DC-Decay measuring methods for a rotor in arbitrary position. The first new method (DC-Decay I) delivers the equivalent circuit with a few measurements. The second new method (DC-Decay III) permits to catch the full equivalent circuit of both axes in only one measurement which is unique and a breakthrough in parameter identification. A new method (DC-Decay II) is used to get the rotor angle. The field current allows to obtain the characteristic reactance xc. To extract the time constants and the reactances an enhancement of "classical" parameter identification algorithms is presented (used for the DC-Decay I method). Simulation and experimental results validate the methods and show their accuracy and drawback.