Methods for Determining the Q-Axis Saturation Characteristics of Salient-Pole Synchronous Machines from the Measured D-Axis Characteristics

Measurement of the Saturation Characteristics in the Quadrature Axis of Synchronous Machines

“…This approach has been accepted by the industry and the research community [5], [7], [10], [11] and its validity has been supported by the results of this paper and other published literature [5], [6], [10].…”

“…For the accurate analysis of the performances of synchronous machines using the two-axis (d-and q-axis) frame models, the direct-(d-) and quadratureaxis (q-axis) saturation characteristics are needed. In fact, the saturation in a synchronous machine can be significant in both its direct and quadrature axes whether it is a cylindrical-rotor or salient-pole synchronous machine [1]- [6]. Usually the d-axis saturation characteristic of a synchronous machine can be measured easily by the open-circuit test with the machine excited from its field winding.…”

Effect of Voltage Sag on the Transient Performance of Saturated Synchronous Motors

“…(dq and Vqd) due to this phenomenon [8,9] in (4) and (5). The d-and q-axis components of the total magnetizing ampere-turns are used in this case to obtain the dand q-axis saturation factors from the corresponding saturation characteristics.…”

“…In the fourth method, the d-and q-axis magnetizing reactances are modified according to the excitations along the direct and quadrature axes and two parameters representing the effect of the cross-magnetizing phenomenon are also included. These two parameters represent the effect of this phenomenon in reducing the d-and q-axis magnetic fluxes that are obtained if the magnetic relationships in the direct and quadrature axes are considered separately and the magnetic coupling between them is ignored [9]. Using these synchronous motor models for the case of a symmetrical three-phase voltage sag at the terminals of a typical synchronous motor, the transient stator and rotor currents, the load angle and the air-gap torque produced during and after the voltage sag have been calculated for the different saturation modelings.…”

Steady-state synchronous machine model which incorporates saturation and cross-magnetization effects

“…Some of the models are very complicated and complex and require complicated identification methods [5]- [7], [11] in order to estimate model parameters. Identification of the steady-state synchronous machine model presented in this paper comes down to solving linear system of equations.…”