Currently, the main technical weaknesses of Electrical Vehicle (EV) are the limitation of the on-board energy storage and the time to recharge it. Despite of recent improvements in batteries, these drawbacks as well as the cost make the EV not yet attractive. Real challenges for Power Electronics engineers are not only the cost reduction through new system optimizations but also the autonomy increase through the global efficiency improvement and the introduction of a cheap fast on-board charger. This paper deals with a new concept of electric powertrain system which is configurable as a battery charger without additional power components. The interest of this particular solution is the full magnetic decoupling between the rotor and the stator during the charging mode which avoid a clutch system, and prevent the rotor from vibrating. The traction system solution is presented, the feasibility of this combination topology is studied and the effect of the electrical machine's windings configuration is analyzed. Some simulation results show the propulsion efficiency is also improved.
Keywords-Electric Vehicle, Plug-in Hybrid Vehicle, Onboard Battery Charger, 3H-bridge, Power Factor CorrectorI.
This paper proposes a set of new techniques to improve the implementation of the SHA-2 hashing algorithm. These techniques consist mostly in operation rescheduling and hardware reutilization, allowing a significant reduction of the critical path while the required area also decreases. Both SHA256 and SHA512 hash functions have been implemented and tested in the VIRTEX II Pro prototyping technology. Experimental results suggest improvements to related SHA256 art above 50% when compared with commercial cores and 100% to academia art, and above 70% for the SHA512 hash function. The resulting cores are capable of achieving the same throughput as the fastest unrolled architectures with 25% less area occupation than the smallest proposed architectures. The proposed cores achieve a throughput of 1.4 Gbit/s and 1.8 Gbit/s with a slice requirement of 755 and 1667 for SHA256 and SHA512 respectively, on a XC2VP30-7 FPGA.
Real-driving emissions (RDE) testing with portable emissions measurement systems (PEMS) during the type approval and in-service conformity of light-duty vehicles was recently introduced in the European Union legislation. In this paper, three PEMS were compared with laboratory analyzers connected to the tailpipe and the dilution tunnel. The tests were conducted with two Euro 6 vehicles (one gasoline and one diesel) performing the World harmonized Light vehicles Test Cycle (WLTC) and a pre-recorded RDE cycle on a chassis dynamometer. The results showed that the differences of the PEMS gas analyzers compared to the laboratory references were typically within 2% for CO2 and 5% for NOx. The CO2 and NOx mass emissions were within 10% and 15%, respectively, with only a few exceptions. The exhaust flow rate measurements were within 10% at low speeds (urban conditions), and 5% at higher speeds. These results confirm the legislated permitted tolerances and the 2017 PEMS uncertainty estimates.
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