There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

This paper reviews the current status and implementation of battery chargers, charging power levels, and infrastructure for plug-in electric vehicles and hybrids. Charger systems are categorized into off-board and on-board types with unidirectional or bidirectional power flow. Unidirectional charging limits hardware requirements and simplifies interconnection issues. Bidirectional charging supports battery energy injection back to the grid. Typical on-board chargers restrict power because of weight, space, and cost constraints. They can be integrated with the electric drive to avoid these problems. The availability of charging infrastructure reduces on-board energy storage requirements and costs. On-board charger systems can be conductive or inductive. An off-board charger can be designed for high charging rates and is less constrained by size and weight. Level 1 (convenience), Level 2 (primary), and Level 3 (fast) power levels are discussed. Future aspects such as roadbed charging are presented. Various power level chargers and infrastructure configurations are presented, compared, and evaluated based on amount of power, charging time and location, cost, equipment, and other factors.

/pdf/review-of-battery-charger-topologies-charging-power-levels-85yy2igx2w.pdf

Review of Battery Charger Topologies, Charging Power Levels, and Infrastructure for Plug-In Electric and Hybrid Vehicles

http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

Energy storage systems (ESSs) are enabling technologies for well-established and new applications such as power peak shaving, electric vehicles, integration of renewable energies, etc. This paper presents a review of ESSs for transport and grid applications, covering several aspects as the storage technology, the main applications, and the power converters used to operate some of the energy storage technologies. Special attention is given to the different applications, providing a deep description of the system and addressing the most suitable storage technology. The main objective of this paper is to introduce the subject and to give an updated reference to nonspecialist, academic, and engineers in the field of power electronics.

Energy Storage Systems for Transport and Grid Applications

The issue of renewable energy is becoming significant due to increasing power demand, instability of the rising oil prices and environmental problems. Among the various renewable energy sources, fuel cell is gaining more popularity due to their higher efficiency, cleanliness and cost-effective supply of power demanded by the consumers. This paper presents a comprehensive review of different fuel cell technologies with their working principle, advantages, disadvantages and suitability of applications for residential/grid-connected system, transportation, industries and commercial applications. Development of mathematical model of fuel cell required for simulation study is discussed. This paper also focuses on the necessity of a suitable power-conditioning unit required to interface the fuel cell system with standalone/grid applications.

A review on fuel cell technologies and power electronic interface

Blushless dc motor

A magnetic bearing actuator is provided to reduce manufacturing costs by solving a problem due to winding by making a drive source with a built-in type BLDC motor. A magnetic bearing actuator includes a magnetic bearing unit(200), a driving motor unit(300), and a heat radiation member. The magnetic bearing unit supports a rotating shaft installed in a hollow case(100) to rotate in a non-contact manner. The driving motor unit rotates the rotating shaft. The heat radiation member is installed adjacent to the outer surface of the case and radiates heat from the case to the outside. The magnetic bearing unit includes a pair of radial magnetic bearings(210) individually arranged at both ends of the rotating shaft and an axial magnetic bearing(220) arranged between the radial magnetic bearings.

Magnetic bearing actuator

Magnet embedded type bldc motor and rotor

For side airbag, the pipe type inflators have been wide used while the disk type inflators have been used for front airbag. For helping to prevent injury and death the airbag inflator system should be design with great care. The present study deal with optimizing the design of side airbag inflator by finite element analysis and design of experiment method. An optimization process was integrated to determine the optimum design variable values related to the side airbag inflator. Free shape optimization method has been carried out to find a optimal shape on an side airbag inflator model. Optimization of the air bag inflator was successfully developed using Sharpe optimization was carried out to find a new geometry. The improved results compared to the base design specification were achieved from design of experiment and optimization.

Optimizing Design of Side Airbag Inflator using DOE Method

This study proposes the method of remaining useful life estimation based on accelerated life test. To estimate the remaining useful life of bearing, the confidence of accelerated life test need to be validated. First, the properties of bearing depend on bearing state are analyzed. The accelerated life test conditions are established following bearing state. In addition, the fault condition is defined by the acoustic noise changes. Finally, the results by normal condition test and accelerated life test are compared to validate the confidence of accelerated life test. By validated accelerated life test, the remaining useful life and changes by bearing degradation can be investigated easily. In addition, accumulating historical data of degraded bearings can be facilitated.

Jin Hur

Papers

Blushless dc motor

Magnetic bearing actuator

Magnet embedded type bldc motor and rotor

Optimizing Design of Side Airbag Inflator using DOE Method

Accelerated Life Test of Bearing Under Electrical Stress