Stability analysis of an asymmetrical six-phase synchronous motor

Abstract

This paper deals the stability analysis of a six-phase synchronous motor using eigenvalue criteria from its linearized model, so that the small displacement stability during steady-state condition can be accessed. Eigenvalue provides a simple but effective means for the stability analysis of a motor. An association between eigenvalues and motor parameters has been established, followed by the formulation of transfer functions and plotting the root locus of system, employing the dq0 approach in the MATLAB environment.

Small signal stability of three-phase and six-phase synchronous motors: A comparative analysis

“…Linearized modeling of a six-phase synchronous motor was carried out by considering some important simplifying assumptions [15][16][17][18] : the two three-phase stator winding sets, namely, abc and xyz, are identical and symmetrical; the effect of harmonics is neglected; and saturation and hysteresis effects are ignored. Six-phase stator winding of the motor was realized by having two sets of three-phase windings, namely, abc and xyz, that were physically displaced by angle ξ = 30° electrical, i.e., an asymmetrical six-phase stator winding.…”

“…It is to be noted that variables with the additional subscript "0" (I d10 , I d20 , I fr0 , I q10 , I q20 ) signify the steady-state values. Rewriting formula (15) in fundamental form gives us = + px Ax Bu (20) where…”

“…where A, I, and λ are the system matrix, identity matrix, and roots of characteristic formula, respectively. A system is said to be stable only if all the real and/or real components of the eigenvalues are negative [14][15][16] .…”

“…Few studies have presented small signal stability analysis of multiphase induction motors, particularly five-phase [13] and six-phase motors [14] . Introductory analysis of a six-phase synchronous motor was presented by the present authors [15] , together with the determination of stability limits for various parametric variations and working conditions [16] . However, a comparative analysis of a synchronous motor with a three-phase and six-phase stator winding configuration has not yet been reported from the stability point of view to the best of the authors' knowledge.…”

Hybrid control of five-phase permanent magnet synchronous machine using space vector modulation

“…In recent years, multiphase machine application has been widely promoted by researchers in many fields such as electronic vehicles, railway traction, all-electric ships, electric aircraft, and wind power generation systems [1][2][3][4][5][6][7]. The raising interest in this type of machines is the result of the advantages it enjoys when compared to the three-phase [1,[3][4][5][7][8][9][10], in terms of the performance they provide, such as better fault tolerance, higher torque density, less torque pulsation, drive noise characteristic improvement, and a smaller sum in ratting per inverter leg [1][2][3][4][5][6][7][9][10][11]; as well as the increase of digital-calculators power [12,13] , and advances in the field of electronic power [6,14]. These industrial applications require torque control with high dynamic performance, good steady-state accuracy, and robustness to different disturbances.…”