Search results for "Global efficiency"
showing 4 items of 4 documents
Active load sharing technique for on-line efficiency optimization in DC microgrids
2017
Recently, DC power distribution is gaining more and more importance over its AC counterpart achieving increased efficiency, greater flexibility, reduced volumes and capital cost. In this paper, a 24-120-325V two-level DC distribution system for home appliances, each including three parallel DC-DC converters, is modeled. An active load sharing technique is proposed for the on-line optimization of the global efficiency of the DC distribution network. The algorithm aims at the instantaneous efficiency optimization of the whole DC network, based on the on-line load current sampling. A Look Up Table, is created to store the real efficiencies of the converters taking into account components toler…
Global Efficiency of Power-Split Hybrid Electric Powertrain
2021
The development of a proper energy management strategy in hybrid electric vehicles is crucial to pursue the best balance between emissions reduction and performance. In this respect, this paper addresses a straightforward method to investigate the behaviour of the hybrid powertrain in steady-state operation in terms of speeds and torques both of the thermal engine and the electric machines. The procedure takes into account the conversion power losses in the internal combustion engine and the electric unit and the mechanical power losses occurring in the power-split transmission. This enables the calculation of a set of maps describing the global efficiency of the hybrid powertrain and the p…
Power Losses Minimization for Optimal Operating Maps in Power-Split HEVs: A Case Study on the Chevrolet Volt
2021
The power-split architecture is the most promising hybrid electric powertrain. However, a real advantage in energy saving while maintaining high performance can be achieved only by the implementation of a proper energy management strategy. This requires an optimized functional design before and a comprehensive analysis of the powertrain losses after, which could be rather challenging owing to the constructive complexity of the power-split transmission, especially for multi-mode architecture with multiple planetary gearing. This difficulty was overcome by a dimensionless model, already available in the literature, that enables the analysis of any power-split transmission, even in full electr…
Remodeling of Cortical Structural Networks in Multiple Sclerosis
2019
Multiple sclerosis (MS) is one of the most frequent immune-mediated disorders of the central nervous system. Pathological events occurring within the white matter and gray matter compartments can be reliably tracked in vivo by magnetic resonance imaging (MRI) but conventional imaging parameters do not reflect the remodeling processes of the brain. Here, we sought to investigate the reorganization of cortical structural networks in a group of patients with MS. For this, 40 patients (mean age ± standard deviation 31.2 ± 7.0 years, 14 males) with relapsing-remitting MS and 40 healthy subjects (27.1 ± 5.0 years, 14 males) were included in the study. From T1-weighted MR image-derived cortical th…