The Experts below are selected from a list of 5250 Experts worldwide ranked by ideXlab platform
Olivie Trescases - One of the best experts on this subject based on the ideXlab platform.
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short circuit fault diagnosis and post fault control with adaptive pll based synchronization for a multi phase quasi square wave dc dc converter
European Conference on Power Electronics and Applications, 2018Co-Authors: Moitaba Ashourloo, Olivie TrescasesAbstract:Fault-tolerant power management units have regained attention due to the rapid development of autonomous vehicles. This paper presents: 1) a fast short-circuit fault diagnosis method, which prevents turning on into a short-circuit, and 2) an adaptive post-fault control for a multi-phase variable-frequency Quasi-Square-Wave (QSW) synchronous buck converter with more than two phases. The converter employs GaN device as the primary switch due to its better figure-of-merit, while using Si device as protection switch due to superior short-circuit immunity. In this paper, the QSW operation mode and a multi-phase structure are combined to achieve enhanced efficiency and fault tolerance. The switching-node voltage during the dead-time intervals is used as the short-circuit fault signature. The adaptive post-fault control utilizes a PLL-based synchronization method in a closed daisy-chain arrangement to: 1) guarantee QSW operation mode regardless of the variable switching frequency due to the Inductance Value tolerance, and 2) automatically adjust the interleaving phase shifts between phases following a fault detection. The effectiveness of the proposed methods is evaluated and verified in a 75-W four-phase system.
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Integrated switched-capacitor-based cold-start circuit for DC-DC energy harvesters with wide input/output voltage range and low Inductance in 40-nm CMOS
2018 IEEE Applied Power Electronics Conference and Exposition (APEC), 2018Co-Authors: D. K. W. Li, Moitaba Ashourloo, Matthias Rose, H J Bergveld, Olivie TrescasesAbstract:This paper outlines an integrated switched-capacitor (SC)-based cold-start circuit for dc-dc energy harvesters that uniquely combines a low cold-start voltage, wide input/output voltage and low Inductance Value in the boost stage. The proposed design specifically targets size-constrained, self-powered Internet-of-Things applications. The proposed design is an SC circuit built from low-threshold-voltage devices operating in the sub-threshold region and provides the drive voltage for high-threshold-voltage devices of the boost dc-dc converter. The SC circuit is an NMOS-based Dickson charge pump driven synchronously with a series of cross-coupled voltage doublers and voltage multiplying gate drivers. The SC circuit, which is integrated together with a boost converter as the dc-dc energy harvester, has been implemented in a 40-nm CMOS process for future system-on-chip integration. The measured results show that with a 4.7 μH boost converter Inductance, the design can start up from typical input voltages as low as 190 mV while offering up to 2.4 V input and 5 V output voltage compatibility.
Henry Shu-hung Chung - One of the best experts on this subject based on the ideXlab platform.
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use of primary side information to perform online estimation of the secondary side information and mutual Inductance in wireless inductive link
Applied Power Electronics Conference, 2015Co-Authors: Jeff Powa Chow, Henry Shu-hung ChungAbstract:It is well-known that the power transfer efficiency of wireless inductive link depends on factors including the mutual Inductance between the primary and secondary coils, quality factors of the coils, and resonant tank components. It is thus advantageous to have the real-time information about the aforesaid factors, in order to determine the optimal operating frequency and monitor the load condition. This paper will present a technique that utilizes the primary-side electrical quantities to perform real-time estimation of the mutual Inductance, Value of the secondary-side resonant capacitor, and electrical quantities on the secondary side. The technique can be applied to three scenarios: 1) with unknown Value of the secondary-side resonant capacitor and known secondary-side voltage, 2) with known Value of the secondary-side resonant capacitor and unknown secondary-side voltage, and 3) unknown Value of the secondary-side resonant capacitor and unknown secondary-side voltage. Detailed mathematical treatment will be given. An experimental prototype using planar transformer has been built and evaluated on a test bed. This technique is also implemented as a control scheme of a cascaded converter to regulate the output power. Experimental results are found to be in close agreement with the theoretical predictions.
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A New $LCL$-Filter With In-Series Parallel Resonant Circuit for Single-Phase Grid-Tied Inverter
IEEE Transactions on Industrial Electronics, 2014Co-Authors: Weimin Wu, Tianhao Tang, Frede Blaabjerg, Henry Shu-hung ChungAbstract:When designing a higher order output power filter for a transformerless grid-tied converter using pulsewidth modulation (PWM), the requirements on the leakage current, the electromagnetic interference (EMI) noise, and the harmonics of the grid-injected current should be addressed. For an LCL-filter-based single-phase grid-tied full-bridge inverter system, it is possible to decrease the total Inductance as well as the size and the cost, if the harmonic currents around the switching frequency can be fully suppressed. In this paper, the grid-injected current harmonics and the conducted EMI noise are investigated for the conventional LCL-filter-based system. Based on this, a modified LCL-filter topology using an extra parallel LrCr resonant circuit is proposed to reduce the total Inductance Value, without increasing the capacitive reactive power. The validity is verified through the experiments on a 500-W 110-V/50-Hz prototype.
Abdesslam Makouf - One of the best experts on this subject based on the ideXlab platform.
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A Fault-Tolerant Control Architecture for Induction Motor Drives in Automotive Applications
IEEE Transactions on Vehicular Technology, 2004Co-Authors: Demba Diallo, Abdesslam Makouf, Mohamed El Hachemi BenbouzidAbstract:This paper describes a fault-tolerant control system for a high-performance induction motor drive that propels an electrical vehicle (EV) or hybrid electric vehicle (HEV). In the proposed control scheme, the developed system takes into account the controller transition smoothness in the event of sensor failure. Moreover, due to the EV or HEV requirements for sensorless operations, a practical sensorless control scheme is developed and used within the proposed fault-tolerant control system. This requires the presence of an adaptive flux observer. The speed estimator is based on the approximation of the magnetic characteristic slope of the induction motor to the mutual Inductance Value. Simulation results, in terms of speed and torque responses, show the effectiveness of the proposed approach.
Benedicte Warotfonrose - One of the best experts on this subject based on the ideXlab platform.
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chemical ordering in bimetallic feco nanoparticles from a direct chemical synthesis to application as efficient high frequency magnetic material
Nano Letters, 2019Co-Authors: Cyril Garnero, Mathieu Lepesant, Cecile Garciamarcelot, Yooleemi Shin, C Meny, Pierre Farger, Benedicte WarotfonroseAbstract:Single-crystalline FeCo nanoparticles with tunable size and shape were prepared by co-decomposing two metal-amide precursors under mild conditions. The nature of the ligands introduced in this organometallic synthesis drastically affects the reactivity of the precursors and, thus, the chemical distribution within the nanoparticles. The presence of the B2 short-range order was evidenced in FeCo nanoparticles prepared in the presence of HDAHCl ligands, combining 57Fe Mossbauer, zero-field 59Co ferromagnetic nuclear resonance (FNR), and X-ray diffraction studies. This is the first time that the B2 structure is directly formed during synthesis without the need of any annealing step. The as-prepared nanoparticles exhibit magnetic properties comparable with the ones for the bulk ( Ms = 226 Am2·kg-1). Composite magnetic materials prepared from these FeCo nanoparticles led to a successful proof-of-concept of the integration on inductor-based filters (27% enhancement of the Inductance Value at 100 MHz).
Yooleemi Shin - One of the best experts on this subject based on the ideXlab platform.
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chemical ordering in bimetallic feco nanoparticles from a direct chemical synthesis to application as efficient high frequency magnetic material
Nano Letters, 2019Co-Authors: Cyril Garnero, Mathieu Lepesant, Cecile Garciamarcelot, Yooleemi Shin, C Meny, Pierre Farger, Benedicte WarotfonroseAbstract:Single-crystalline FeCo nanoparticles with tunable size and shape were prepared by co-decomposing two metal-amide precursors under mild conditions. The nature of the ligands introduced in this organometallic synthesis drastically affects the reactivity of the precursors and, thus, the chemical distribution within the nanoparticles. The presence of the B2 short-range order was evidenced in FeCo nanoparticles prepared in the presence of HDAHCl ligands, combining 57Fe Mossbauer, zero-field 59Co ferromagnetic nuclear resonance (FNR), and X-ray diffraction studies. This is the first time that the B2 structure is directly formed during synthesis without the need of any annealing step. The as-prepared nanoparticles exhibit magnetic properties comparable with the ones for the bulk ( Ms = 226 Am2·kg-1). Composite magnetic materials prepared from these FeCo nanoparticles led to a successful proof-of-concept of the integration on inductor-based filters (27% enhancement of the Inductance Value at 100 MHz).