Multiphase machines have been used widely in electric ship propulsion, air-craft drives, locomotive traction, and high-power industrial applications. The fault-tolerant capability is one of the most interesting topics in multiphase stand-alone motor drives since no additional hardware is required to provide the additional degree of freedom if they are properly configured. The fault-tolerant control strategies, suitable for open-phase fault operation of five-phase concentrated-full-pitch winding induction motor drives, are studied in this paper. In order to compare the performance of the above strategies, a more general mathematical model considering third harmonic component based on symmetric component theory is established. Then expressions of the average torque, torque ripple, total copper loss and efficiency are derived. Finally, comparative results can be used as guidelines for the engineering application.
Direct Model Predictive Power Control (DMPPC) has emerged as a viable alternative for grid-tied Active Front End (AFE) power converters. However, its one-switching-vectorper-sampling-interval character leads to big ripples in its control variables. This work proposes a Performance-Enhanced Direct Multiple-Vector Model Predictive Power Control (DMV-MPPC) solution for grid-tied AFEs directly implementable on an FPGA. The proposed control scheme is compared with the classical DMPPC. The presented experimental results illustrate that the control performance can be significantly improved by the proposed DMV-MPPC scheme.
Many applications require a high step-down ratio in DC-DC converters. Hybrid structures, using switched-capacitors and/or switched-inductors, have been reported as an alternative to high frequency transformer converters. The object of this paper is a comparative study of a switched-capacitor hybrid buck DC-DC converter (HBDC) and a classical buck DC-DC converter (BDC) for automotive applications. The hybrid converter uses a bank of switched capacitors in order to halve the input voltage available to the regular buck converter. Analytical aspects and digital simulations, validated through experimental results obtained from a full scale, 1kW rated power prototype, are presented for this purpose.
