Efficiency improvement and power loss breakdown for a Lundell-alternator/active-rectifier system in automotive applications

A control strategy for a conventional Lundell alternator and an active-rectifier using different modulation schemes was proposed in previous work. The modulation techniques examined indicated that the system could operate more efficiently than a passive rectifier over a certain speed and power range. This paper extends the modulation scheme analysis using a SVM scheme with six commutations per switching cycle, giving better electrical and overall efficiency. Furthermore, a power loss breakdown is performed for the active-rectifier with the assistance of experimental and simulation results of double pulse tests. Switching loss estimation curves are produced allowing the loss examination of the active-rectifier. Switching losses account only for a minor portion of the total rectifier losses in comparison to conduction losses. Finally, a higher dc-link voltage of 14.5 V was introduced using SVM scheme, giving better efficiency, in order to exploit further the rectifier loss distribution

Energy efficiency improvement through MPC-based peripherals management for an industrial process test-bench

High energy costs evince the growing need for energy efficiency in industrial companies. This paper presents a solution at the industrial machine level to obtain efficient energy consumption. Therefore, a controller inspired by the well-known model predictive control (MPC) strategy was developed for the management of peripheral devices. The validation of the control requires a test-bench to emulate the energy consumption of a manufacturing machine. The test-bench has four devices, two used to emulate the periodic and fixed energy consumption of the manufacturing process and two as peripherals, subject to rules associated with the process. Consequently, a subspace identification (SI) was employed to identify energy models to simulate the behavior of the device. As a final step, a performance comparison between a rule-based control (RBC) and the proposed predictive-like controller revealed the remarkable energy savings. The MPC results show an energy saving of around 3% with respect to RBC as well as an instant maximum energy consumption reduction of 8%, approximately.Peer ReviewedPostprint (published version

Efficiency Improvement of Fault-Tolerant Three-Level Power Converters

Fault-tolerant power converters play a critical role in the transportation electrification. However, fault-tolerant operation, high efficiency, and low cost usually result in design criteria that have conflicting constraints and goals. The majority of the fault-tolerant power converter topologies presented in the literature confirm these conflicts. In this paper, three types of fault-tolerant neutral-point clamped (NPC) converters are investigated. Various modulation strategies are explored to reduce the losses of the redundant phase leg. The simulation and experimental results show that the Switching Frequency Optimal Phase opposition Disposition modulation strategy is the most effective approach in minimizing the losses in the redundant phase leg

Strong efficiency improvement of SOI-LEDs through carrier confinement

Contemporary silicon light-emitting diodes in silicon-on-insulator (SOI) technology suffer from poor efficiency compared to their bulk-silicon counterparts. In this letter, we present a new device structure where the carrier injection takes place through silicon slabs of only a few nanometer thick. Its external quantum efficiency of 1.4 • 10−4 at room temperature, with a spectrum peaking at 1130 nm, is almost two orders higher than reported thus far on SOI. The structure diminishes the dominant role of nonradiative recombination at the n+ and p+contacts, by confining the injected carriers in an SOI peninsula.\ud With this approach, a compact infrared light source can be fabricated using standard semiconductor processing steps.\u

Silicon solar cell efficiency improvement: Status and outlook

Efficiency and operating life is an economic attribute in silicon solar cells application. The efficiency improvements made during the 30 year existence of the silicon solar cells, from about 6% efficiency at the beginning to 19% in the most recent experimental cells is illustrated. In the more stationary periods, the effort was oriented towards improving radiation resistance and yields on the production lines, while, in other periods, the emphasis was on reaching new levels of efficiency through better cell design and improved material processing. First results were forthcoming from the recent efforts. Considerably more efficiency advancement in silicon solar cells is expected, and the anticipated attainment of efficiencies significantly above 20% is discussed. Major advances in material processing and in the resulting material perfection are required

Efficiency Improvement of Measurement Pose Selection Techniques in Robot Calibration

The paper deals with the design of experiments for manipulator geometric and elastostatic calibration based on the test-pose approach. The main attention is paid to the efficiency improvement of numerical techniques employed in the selection of optimal measurement poses for calibration experiments. The advantages of the developed technique are illustrated by simulation examples that deal with the geometric calibration of the industrial robot of serial architecture

Efficiency improvement of pyrolysis

Ethylene production by pyrolysis of hydrocarbon gases (ethane, propane, butane) and liquid fractions provides better selectivity to ethylene at higher temperatures, as has been well documented in studies. Temperature increase accelerates chainradical reactions of ethylene formation. Acceleration of chain-radical process can be achieved at a given temperature by the presence of an initiating agent of radical formation in the feedstock. Bimolecular reaction of allene (propadiene) with either alkane or alkene hydrocarbons and is an extremely rapid reaction of radicals formation because the endothermicity of this reaction is small and steric ratio is high. This paper considers the use of allene as the initiator of chainradical reactions of pyrolysis. © 2014 WIT Press.International Journal of Safety and Security Engineering;International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

ENERGY EFFICIENCY IMPROVEMENT PLAN

As climate change issues and increasing CO2 emissions are rising, "green energy" or renewable energy sources include solar, wind power, biomass, geothermal energy, etc. One of the most important sectors of the economy is energy. Its main tasks are energy recovery, its processing in all types of energy and delivery to consumers. No energy development is possible without the development of any economic sector. Energy is mainly used for energy productio

Process Flow Efficiency Improvement

My research focuses on a process flow inefficiency and a lack of documentation that was no provide by previous employees. Instead of creating documentation that will help future employees perform the task we relied heavily on verbal communication which is good way of communication, but it wasn\u27t right for what we wanted to accomplish. I took a action based approach to tackle this problem by creating documentation which sets the expectations of what we need to accomplish how to accomplish. I created a flow chart and a procedure which was hosted on SharePoint for all to be available. I look to the future because the actions we take now will make others successful in the future