Finite Element Computation of Transient Parameters of a Salient-Pole Synchronous Machine

Abstract

This paper presents a novel method for calculating the transient parameters of a saturated salient-pole synchronous machine (SPSM) with damper cage using finite element analysis. All detailed leakage inductances in a modified d-q model are discussed and separately extracted. In addition; the frozen permeability method is used in a 2-D finite element analysis to consider saturation and skin effects for determining the inductances. The terminal reactance parameters are obtained from all elements of the d-and q-axis equivalent circuits in all the chosen time constants during the transient process. The variation of leakage inductances of the SPSM in transient processes is also investigated and discussed. To determine transient time constant parameters; the Prony algorithm is applied in the presented method. A program developed to automatically solve the simulation and computation with the proposed method is described. This method is applied to a prototype and validated by experimental results. Some discussion about the relationship between rotor geometric design and the transient parameters of SPSMs is provided. The variation of leakage magnetic field of SPSMs in transient processes is also investigated. This method can be applied in transient parameter estimation and optimization of SPSMs in the design stage.

A Step-by-Step Procedure to Perform Preliminary Designs of Salient-Pole Synchronous Generators

“…If the self-inductance of two phases in series L 2ps has only the second-order harmonic and the DC components different from zero, the direct axis inductance can be considered as half of L 2ps maximum value, whereas the quadrature axis inductance can be approximated as half of L 2ps minimum value [17]. Other methods to obtain the inductances from finite element simulations can be found in [16,18], whereas their calculation by analytical procedures is presented in [19,20].…”

“…On the other hand, experienced designers could improve the proposed method, including complexity, to achieve a more realistic and competitive machine. Moreover, specialists in other areas, such as power electronics, power system stability, or optimization, generally have some trouble finding all necessary data of electrical machines to use in their research and could achieve all generator parameters from their own design (a method for transient parameter determination to model the generator by an equivalent electrical circuit is presented by [16]). Finally, it can be used as an undergraduate course in electrical engineering to introduce electric machine design and deepen the students' knowledge about synchronous generators and their applications.…”

Verification Methodology for Simulation Models of the Synchronous Generator on Transients Analysis

“…In [9], subtransient reactances and time constants are calculated by both analytical and finite-element methods, and applied to the classical circuit-theory simulation of a short-circuit fault. The terminal reactance parameters during the transient process were obtained using a 2D finite element analysis and validated by experimental results in [10]. Transient torques that appeared during faulty synchronization were observed in [11], and the physical quantities existing during faulty synchronization were compared with a threephase sudden short-circuit state.…”

Core Loss Analysis of Interior Permanent Magnet Synchronous Machines under SVPWM Excitation with Considering Saturation

“…In the model, an additional flux density higher-order term and an additional flux density lower-order term are introduced, to allow consideration of the increased eddy current loss and the local hysteresis loss caused by magnetic saturation and the harmonic field, respectively. Moreover, the rotating magnetic field is regarded as two perpendicular alternative magnetic fields in the stator core loss calculation model, in which the core loss density can be expressed as [25]: (11) where Kh, Ke and Kexc are the coefficient of hysteresis loss, eddy current loss and eddy current excess loss, respectively; Bkmax is the kth harmonic amplitude of the major axis flux density; Bkmin is the kth harmonic amplitude of the minor axis flux density; Kr is the core loss coefficient of rotational magnetic …”