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This paper proposes a control schema for permanent magnet machines, which is synthesized by field-oriented control, synchronous pulse width modulation and phase-lock loop based sampling synchronization. Switching frequency of inverters in electric locomotive applications is limited by considering switching losses. Lower switching frequency deteriorates performance of machines, e.g., extra machine...
Servo motors are widely used in many industrial applications. These motors require precise control of acceleration, speed, and position. Different designs can be found in the literature. This paper will compare the response of two of the common types and will propose a new servo motor design that uses a smaller amount of magnet, lowering the price of the motor. The proposed motor would be able to...
In order to improve the robustness of fault diagnosis method based on model in the modular multilevel converter, an improved predictive model of the circulating current is established. A correction method is proposed to compensate for the uncertainties of the parameters and the measurement errors, and the disturbances are eliminated by using multi-step prediction method. The fault detection method...
Battery energy storage system based on modular multilevel converter (MMC-BESS) has many advantages such as easy expansibility and high reliability. With multiple submodules (SM), the corresponding SM fault ride-through method is mandatory to reduce the construction redundancy and improve the operational reliability. This paper proposes a redistributed pulse width modulation (R-PWM) method for MMC-BESS...
Hot reserved redundant sub-modules significantly increase the reliability of MMC systems equipped with considerable sub-modules. This paper presents a fault-tolerant operation scheme for an MMC with a distributed control architecture. The MMC output, internal dynamics and the average capacitor voltages are balanced and well-regulated while asymmetrical sub-modules in arms are bypassed due to faults...
The MMC is an emerging and highly attractive multilevel converter topology for medium and high voltage applications. Various modulation strategies are being used to control the MMC system. Balancing the cascaded submodule voltages and eliminating the second order circulating current in the leg of the MMC system are the main concerns of many researchers in the area of MMC system. Mostly, for circulating...
A hybrid resonant zero-voltage zero-current switching three-level converter is proposed in this paper, which undergoes half of the input voltage for switches. The proposed converter, utilizing two transformers, adopts IGBTs for all six power switches and operates in discontinuous current mode and can achieve zero-current switching for the four main switches and rectifier diodes over the whole load...
This paper presents a new investigation of the permanent magnet dimension selection for an AlNiCo based variable-flux machine based on the permanent magnet operating point. To do this, the magnetic features of an AlNiCo permanent magnet material are reviewed and an analytical method to estimate the magnetization level of the permanent magnet at different operation conditions is presented. Moreover,...
This presentation reviewed the basics of multi-objective optimization algorithms and showed their use in SyR-e to design surface PM machines. Next steps for PM machines in SyR-e: • Preliminary design (some features for fractional slot windings needs to be improved) • Sleeve sizing equations • Include other type of PM rotors • … suggestions?
This paper proposed an unequal zero voltage vector distribution modulation strategy to suppress the zero-sequence current of five-phase open-winding fault-tolerant fractional-slot concentrated-winding interior-permanent-magnet (FTFSCW-IPM) motor driving system with common DC bus. Compared with the conventional eliminating common-mode voltage vectors modulation strategy, this method can well suppress...
Variable magnetization pattern machines (VMPMs) capable of dynamic changes in the magnetization pattern and magnitude are discussed in this paper. These machines can behave like brushless DC machines if they have a uniform magnetization pattern. If the magnetization pattern on the permanent magnet is shaped to be sinusoidal through a controlled demagnetizing process, they could behave like brushless...
Variable flux memory (VFM) permanent magnet (PM) machines exhibit an additional degree-of-freedom for control, i.e. PM magnetization state, and thus excellent flux controllability. Moreover, the hybrid PM topologies having variable PM (VPM) with low coercive force and constant PM (CPM) with high coercive force at the same time, are employed to improve the torque density and the flux controllability...
This paper presents the design, development, and evaluation of a high power, i.e., 1200-V/600-A, double-sided multichip phase-leg IGBT module with the purpose of increasing power density compared with conventional wire-bonded IGBT modules. Nanosilver paste is chosen as the die-attach material so as to increase the maximum application temperature by avoiding the creep failure at high temperatures compared...
In large power electronic systems like a wind farm, the mutual interactions between the control systems of the power converters can lead to various stability and power quality problems. In order to predict the system dynamic behavior, this paper presents an approach to model a wind farm as a Multi-Input Multi-Output (MIMO) dynamic system, where the current control loops with Phase-Locked Loops (PLLs)...
In this study slip permanent magnet couplers (slip-PMC) for wind turbine application are introduced and their analysis technique used in finite element method (FEM) is presented. Two optimization methods are employed in determining optimum permanent magnet (PM) rotors for a fixed wound rotor size. The machine topologies, namely surface-mounted and spoke-mounted PM rotor topologies are evaluated against...
A boost dc-dc dimmable AC-LED driver is presented in this paper based on Zero Current Switching Quasi-Resonant Converters (ZCS-QRCs). The proposed driver is based on replacing the diode in conventional converter topologies (i.e. buck, boost or buck-boost) by a string of High-Brightness Light-Emitting Diodes (HB-LED). Hence, the HB-LED string will be working as the rectifier of the converter switching...
Sparse representation of massive condition monitoring signals is an effective approach to save the cost for data storage and transmission in fault diagnosis of wind turbines. This paper explores a sparse representation method over a new dictionary designed particularly for bearing vibration signals of wind turbines operating under varying-speed conditions. First, the time-varying shaft rotating frequency...
This paper presents a high-power-density high-power-factor GaN-based two-stage electrolytic-free offline LED driver. The LED driver achieves high power density through the use of a hybrid film-ceramic stacked switched capacitor (SSC) energy buffer, and a comprehensive optimization methodology that evaluates various converter topologies and designs, and minimizes overall system volume while maintaining...
In this paper, the design and operation of two 650 V/ 60 A Gallium Nitride (GaN) devices in parallel is discussed in detail, further, the challenges faced and the trade-offs required for paralleling high speed GaN devices are also examined. The dynamic characterization of two devices in parallel is presented in detail. The phase leg design requires both power loops and gate loops to be as small and...
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