Search

Dual-three-phase permanent magnet synchronous machines (DTP-PMSMs) are famous for their fault-tolerant capability. However, the complex modeling, high copper loss, and torque ripple under postfault operation limit their further application. In this article, a fault-tolerant control (FTC) strategy is developed for DTP-PMSMs under the open-phase fault (OPF) with straightforward modeling and smooth output torque. The virtual healthy DTP-PMSM model, where the coordinate transformation, the modulation strategy, and the controller structure remain unchanged under OPF, is adopted in the proposed FTC scheme. And the current references are derived in sinusoidal waves with minimum copper loss. The inaccurate transmission of control signals under OPF is also focused on. Comprehensive theoretical analysis shows the relationship between the controller output voltage and the actual stator voltage should be considered in the proposed FTC strategy; otherwise, distortion in torque and current will be introduced. The voltage compensation is utilized to compensate for the voltage difference and ensure the smooth torque output. Besides, a quasi proportional resonance controller is designed to further suppress the residual torque ripple. The proposed strategy will not induce complex implementation and heavy computation burden. The simulation and experimental results prove the analysis and the effectiveness of the proposed strategy. [ABSTRACT FROM AUTHOR]

The aim of this study is to introduce the maximum torque per total ampere (MTPTA) control strategy for brushless doubly fed induction machine drives taking iron loss into account. In this regard, the condition for realizing the MTPTA is investigated in the presence of iron loss by a theoretical approach. It is shown the proposed strategy is realized when the MTPTA criterion tracks zero as reference signal. As a result, the current is not only shared between the stator windings fairly but also total stator currents are minimized for a given torque. The experimental results confirm the performance of the proposed control strategy. [ABSTRACT FROM AUTHOR]

Multireference frame based asymmetric six-phase interior permanent magnet motor modeling and control strategy under single open-phase fault are investigated in this article. The motor modeling under healthy operation is firstly established based on a dual dq-axis synchronous rotating frame. With this dual dq-axis frame, the motor modeling considering the magnetic saturation effect under open-phase fault has been derived. By introducing a dual-direction rotating frame, the stator current under single open-phase fault can be treated as the sum of a positive current sequence and a negative current sequence. With this dual-direction rotating frame, the two current sequences can be transformed into two dc components for fault-tolerant operation. Fault-tolerant control schemes with maximum torque per ampere for copper loss minimization and torque maximization are developed, respectively. Finally, the validity of the proposed modeling and control are evaluated by experiments under both steady and transient scenarios. [ABSTRACT FROM AUTHOR]