Abstract:
The work presented in this thesis develops a new concept for independent control of two
five-phase permanent magnet synchronous machines (PMSMs) connected in parallel and fed
by a single five-leg inverter. The proposed scheme presented a reduction in the number of
inverter legs, when compared to an equivalent two-machine three-phase drive system. It can be
seen from the developed model only two stator current components (d-q) are responsible for
torque and flux production, while other components (x-y) do not used. Through an appropriate
phase transposition of the stator windings, the other components (x-y) it can be used to connect
in parallel the other machine in such a way that the torque and flux producing current
components of the first machine do not affect the production of torque and flux of the second
machine and vice versa.
The purpose decoupled control strategies for the two five-phase PMSM connected in
parallel are made by using filed oriented control (FOC), conventional direct torque control
(DTC) and DTC-SVM; all are based on sliding mode control (SMC). The SMC law improve
the stability and robustness of parallel-connected two five-phase PMSMs with parameter
variations, reduce the ripples of the torque and flux as well as improve the dynamic
performance. In order to increase the proposed drive robustness and decrease the number of
sensors as well as its cost, an Extended Kalman Filter (EKF) and sliding mode observer (SMO)
scheme have been adopted. The results show better speed tracking performance at both dynamic
and steady state, acceptable estimations errors, robustness in different tests
