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Comparison of SiC MOSFET-based and GaN HEMT-based High-efficiency High-power-density 7.2 kW EV Battery Chargers
No full textAs two exemplary candidates of wide-bandgap devices, SiC MOSFETs and GaN HEMTs are regarded as successors of Si devices in medium-to-high-voltage (\u3e1200 V) and low-voltage (\u3c;650 V) domains, respectively, thanks to their excellent switching performance and thermal capability. With the introduction of 650 V SiC MOSFETs and GaN HEMTs, the two technologies are in direct competition in \u3c;650 V domains, such as Level 2 battery chargers for electric vehicles (EVs). This study applies 650 V SiC and GaN to two 240 VAC/7.2 kW EV battery chargers, respectively, aiming to provide a head-to-head comparison of these two devices in terms of overall efficiency, power density, thermal performance, and cost. The charger essentially is an indirect matrix converter with a dual-active-bridge stage handling the power factor correction and power delivery simultaneously. These two chargers utilise the same control strategy, varying the phase-shift and switching frequency to cover the wide input range (80-260 VAC) and wide output range (200 V-450 VDC). Experimental results indicated that at the same efficiency level, the GaN charger is smaller, more efficient and cheaper, while the SiC charger has a better thermal performance
Advanced Energy Storage Technologies and Their Applications (AESA2017)
Get PDFThe depletion of fossil fuels, the increase of energy demands, and the concerns over climate change are the major driving forces for the development of renewable energy, such as solar, wind and wave energy. However, the intermittency of renewable energy has hindered its large-scale deployment, which, therefore, has necessitated the development of advanced energy storage technologies. The use of large-scale energy storage can effectively improve the efficiency of energy resource utilization, and increase the adoption of variable renewable resources, the energy access, and the end-use sector electrification (e.g., electrification of transport sector)
Carbon Nanofibers (CNFs) Supported Cobalt-Nickel Sulfide (CoNi 2 S 4) Nanoparticles Hybrid Anode for High Performance Lithium Ion Capacitor
Get PDFLithium ion capacitors possess an ability to bridge the gap between lithium ion battery and supercapacitor. The main concern of fabricating lithium ion capacitors is poor rate capability and cyclic stability of the anode material which uses sluggish faradaic reactions to store an electric charge. Herein, we have fabricated high performance hybrid anode material based on carbon nanofibers (CNFs) and cobalt-nickel sulfide (CoNi2S4) nanoparticles via simple electrospinning and electrodeposition methods. Porous and high conducting CNF@CoNi2S4 electrode acts as an expressway network for electronic and ionic diffusion during charging-discharging processes. The effect of anode to cathode mass ratio on the performance has been studied by fabricating lithium ion capacitors with different mass ratios. The surface controlled contribution of CNF@CoNi2S4 electrode was 73% which demonstrates its excellent rate capability. Lithium ion capacitor fabricated with CNF@CoNi2S4 to AC mass ratio of 1:2.6 showed excellent energy density of 85.4 Wh kg−1 with the power density of 150 W kg−1. Also, even at the high power density of 15 kW kg−1, the cell provided the energy density of 35 Wh kg−1. This work offers a new strategy for designing high-performance hybrid anode with the combination of simple and cost effective approaches
