Low-Order Space Harmonic Modeling of Asymmetrical Six-Phase Induction Machines

Abstract

Multiphase machines are commonly analyzed using vector space decomposition modeling technique, where the original phase variables are decomposed into multiple orthogonal subspaces. The machine torque production and, therefore, its dynamic response are mainly decided from the α-β fundamental subspace. In the available literature, other non-fundamental subspaces are commonly regarded as the non-flux/torque producing subspaces while mainly contributing to the extra winding joule losses. Although the primitive harmonic-free models are usually assumed for these secondary subspaces in the asymmetrical six-phase induction machines, a clear evidence to include or discard the effect of the low-order space harmonics of the air gap flux distribution under different neutral configurations has not been established so far. To this end, this paper investigates the effect of the induced air gap harmonics mapped to the x-y and zero subspaces on the dynamic modeling and, hence, the dynamic response of an asymmetrical six-phase induction machine. An improved space harmonic model is, then, proposed to better explore/simulate their effect under both healthy as well as fault conditions. The proposed model is experimentally validated using a 1.5-kW prototype induction machine.

Multi-Harmonic Currents Control Strategy for Five-Phase Permanent Magnet Machine with non-sinusoidal back-EMF

“…It is obvious that the 3 rd harmonic is 35.7% of the fundamental one, the 5 th harmonic accounts for 4.6%. Therefore, the relation between harmonic flux linkages can be obtained as: From (14) and ( (16) According to (6) and (16), with the aid of Mathcad and Matlab Optimization Toolbox in Appendix A, the optimal injection coefficients for the maximum torque per peak current are derived From 17, the electrical torque (16) can be rewritten as:…”

“…These outstanding merits make some unique characteristics for multiphase machines. One of them is to inject low-order harmonic components into phase currents to obtain high torque density [5], [6].…”

Parameters estimation for multiphase induction machine with concentrated windings through finite element method

“…J(dω s1 /dt) = T e − T L − Dω s1 (22) The mathematical model based on the MATLAB/Simulink is compared with the experimentation in the transient response and steady performance during the start-up period. The asymmetrical operation for open phase fault is carried out to highlight the effect of the parameters of harmonic subspaces [20]. The open-loop freerunning mode and optimal current control scheme are employed to perform the simulation and experiment [21].…”

Modeling and analysis of novel six‐phase DFIG through asymmetrical winding structure for disperse generation

“…Since, the first record of a multi‐phase self‐excited induction machine (MPSEIG), known to the authors, at the last of 60s. After that number publication came in to picture but all of them are based on MPSEIG 7‐12 …”