Matching Items (3)
Wide Bandgap Semiconductor Based Electric Vehicle Charging Systems: Modeling, Magnetics, and Control
Description
Adhering to an ever-increasing demand for innovation in the field of onboard electric vehicle (EV) charging, several technical aspects pertaining to the design and performance enhancement of integrated multi-port charger topologies are discussed in this study. This study also elucidates various research challenges pertaining to each module of the topology and elucidates technically validated solutions for each.Firstly, targeting the input side totempole power factor corrector (TPFC) circuit, a novel digital filter based Active Mitigation Scheme (AMS) is proposed to curb the third harmonic component, along with a novel discretized sampling-based robust control scheme. Experimental verification of these techniques yields an enhanced Total Harmonic Distortion (THD) of 1.68%, enhanced efficiency of 98.1% and resultant power factor of 0.998 (lag).
Further, focusing on the bidirectional CLLC based DC/DC converter topology, a general harmonic approximation (GHA) based secondary side turnoff current minimization technique is discussed. Numerous fabrication and design-based constraints and correlations for parametric modelling of high frequency planar transformer (HFPT) are explained with analytical and 3D Finite Element Analysis (FEA) findings. Further, characterization of the plant transfer function of all-inclusive CLLC model is described along with hybrid Sliding Mode Control (SMC) based control scheme. The steady state experimental results at 1kW rated load show a peak efficiency of 98.49%, while the quantification of dynamic response portray a settling time reduction of 46.4% and an over/undershoot reduction of 33%.
Further, comprehensive modeling of triple active bridge (TAB) DC/DC converter topology is presented with special focus on the control scheme and decoupling capabilities to independently regulate the output bridges. With an objective to reduce the overall losses and to add a dimension of controllability, a three-loop control scheme is proposed with power flow optimization. Inculcating the benefits of multiport and resonant topologies, a comprehensive multi-variable loss optimization study of a Triple Active C^3 L^3 (TAC^3L^3) converter is discussed. The performance of eight different hybrid modulation schemes is compared with respect to the developed global loss minimization objective function. Experimental validations for various loading conditions are presented for a wide-gain bidirectional operation (400V/500-600V/24-28V), portraying a peak converter efficiency of 97.42%.
ContributorsChandwani, Ashwin Vijay (Author) / Mallik, Ayan (Thesis advisor) / Ayyanar, Raja (Thesis advisor) / Kannan, Arunanchala Mada (Committee member) / Hedman, Mojdeh (Committee member) / Arizona State University (Publisher)
Created2022
Description
Due to the reduced fuel usage and greenhouse emission advantage, the sales of electric vehicles (EV) have risen dramatically in recent years. Generally speaking, the EVs are pursuing higher power and lighter weight, which requires higher power density for all the power electronics converters in the EVs. To design higher density power converters, three key emerging power electronics technologies are investigated in this study. First, the PCB-based magnetics are beneficial for improving the power density due to their low-profile structure. However, the high winding capacitance is considered one of the significant drawbacks of PCB-based magnetics. In this study, a novel winding structure is proposed to cut down the winding capacitance by 75% with little compromise of the winding loss. Second, the synchronous rectifiers (SR) are usually utilized to improve the system efficiency and power density compared with the conventional diode bridge rectifiers for the AC/DC stage in the power converters. The SRs are desired to be turned off at current zero-crossing to generate a minimal loss. However, the precise current zero-crossing detection is very challenging in high-frequency and high-power-density converters. In this study, a high-dv/dt-immune and parameter-adaptive SR driving scheme is proposed to guarantee the zero-current switching (ZCS) of SRs in various operating conditions and improve the system efficiency by 1.23%. Finally, Gallium Nitride (GaN) semiconductors are considered less lossy than Silicon (Si) semiconductors. However, the voltage rating of the commercial GaN HEMTs is limited to 600/650 V due to the lateral structure, which is not suitable for the 800 V or higher dc-link voltage EV systems. Stacking the low-voltage rating devices is a straightforward approach to sustain higher dc-link voltage. However, unbalanced voltage sharing can occur, which can damage the low-voltage rating devices in the stack. In this study, a novel active current source gate driver is proposed to suppress the over-voltage of the stacking devices below 10% for all operating conditions without sacrificing switching speed or switching energy. The above emerging power electronics technologies are investigated thoroughly in the dissertation. The proposed approaches are practical for improving power converters’ density in future EV applications.
ContributorsZhang, Zhengda (Author) / Lei, Qin Q.L. (Thesis advisor) / Ayyanar, Raja R.A. (Committee member) / Yu, Hongbin H.Y. (Committee member) / Pal, Anamitra A.P. (Committee member) / Ranjram, Mike M.R. (Committee member) / Arizona State University (Publisher)
Created2021
Description
Power amplifiers and tuneable matching networks for plasma generation systems arebeing continuously advanced, and recent innovations have shown tremendous
improvements in their size, efficiency, and capability. These improvements must
ultimately be validated on a live plasma chamber, but this is costly and time-consuming,
and debugging errors or failures is a challenge owing to the highly dynamic nature of
the plasma and the experimental prototype nature of the advancements. This work
addresses this challenge by developing a reactive load emulation system that can mimic
the inductive reactance of a live plasma chamber. This includes a study of the saturation
characteristics of low-permeability, high-frequency materials, demonstration of the
suitability of this method for plasma emulation, and the design of an inductor array
platform which verifies the approach.
ContributorsTagare, Darshan Ravindra (Author) / Ranjram, Mike (Thesis advisor) / Mallik, Ayan (Committee member) / Ayyanar, Raja (Committee member) / Arizona State University (Publisher)
Created2024