Space vector control of permanent Magnet Brushless DC Machines

Design of flux‐weakening space vector control algorithms for permanent magnet brushless DC machines on suitable synchronous reference frames

“…This does not represent a critical issue for managing current limitation constraint as far as average values are concerned, as pointed out in (20) and (21). However, voltage saturation constraint is affected noticeably by (25), as highlighted by (24); in particular, C V radius varies significantly within each operating sector, together with C V centre. Consequently, although torque and power management benefits from the ft synchronous reference frame, managing voltage saturation constraint effectively is still a difficult task in this synchronous reference frame, may resulting in weak PMBDCM flux-weakening capability.…”

“…by carrying out current commutation in advance [17,18] or by varying DC-link voltage suitably [19,20]. The application of direct torque control has been also investigated [21,22], together with various vector control systems [23][24][25][26][27][28][29][30]. Most of these research efforts have been focused on suppressing or reducing PMBDCM torque ripple due to current commutation, but enhancing PMBDCM flux-weakening capability has been sometimes also consider [16-18, 23, 29].…”

“…In this regard, the space vector control (SVC) presented in [25] is based on a novel ft reference frame, which enables identifying torque and demagnetising current components clearly. Consequently, PMBDCM torque and flux-weakening operation needs can be satisfied simultaneously, resulting in enhanced performances compared to conventional current commutation control approaches [25]. However, the SVC proposed in [25] does not exploit any flux-weakening capability because the demagnetising current component is held constant at zero at any PMBDCM operating condition.…”

“…Therefore, a demagnetising current loop has been designed in [46] by means of a voltage follower PI regulator [34]; the latter processes the voltage deficit detected on the DC-link at the aim of determining the most suitable reference demagnetising current profile beyond the rated speed. Hence, in [46], a flux-weakening SVC (FW-SVC) is applied for driving the high-speed PMBDCM designed in [47], in comparison with a conventional current commutation control and with the SVC already proposed in [25]. However, although the FW-SVC proposed in [46] shows improved performances compared to the other two PMBDCM control approaches in terms of both constant-power speed range (CPSR) and maximum speed, the latter are still quite far from the targets foreseen in [47].…”

A New Approach of Minimizing Commutation Torque Ripple for BLDCM

“…The trajectories of the three phase currents are calculated by the given torque and the optimized result of copper loss and motor torque equations. Although other papers have already dealt with the current optimizing method for BLDCM, the decoupling control involving the d q synchronous frame is always adopted in analyses or experiments [12][13][14][15][16]. Unlike the work above, this paper provides a current optimizing method in the natural a-b-c reference frame and its properties are compared with the traditional method.…”