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

This paper presents the design and analysis of a linear actuator for vehicle Eco-Pedal system. To prevent the excessive gas consumption for fuel-efficient vehicle the electric actuator produces a counter force to the vehicle's pedal to be pressed stiffly. Major performances of the actuator are required such as a high force density and a low detent force. In this paper, the analysis and design technique of the actuator thrust is based on an analytical method, and the advisability of the design result is verified with both the result of the experiment and the result of the finite element method.

Analysis and Design of Slotted Tubular Linear Actuator for the Eco-Pedal System of a Vehicle

This paper presents analysis and design methodology of single-phase line-start permanent-magnet synchronous (LSPM) motors. The d-q-axes inductances of LSPM motors have a nonlinear variation according to the current and the load angle. The variation of d-q-axes inductances due to load angle is calculated by finite-element method in steady state. Iron loss is analyzed considering the harmonics of the flux density waveforms using iron loss curves. The validity of the presented analysis method considering the variation of the d-q-axes inductances is verified by comparison with experimental results.

Analysis of single-phase line-start permanent-magnet motor considering iron loss and parameter variation with load angle

A stator turn fault in a symmetrical three-phase machine cause a large circulating current to flow and subsequently generated excessive heat in shorted turns, generate irregular control current of the three phase leads to demagnetization. The demagnetization of PM occurred distortion of air-gap magnetic flux distribution caused deterioration of their torque, mechanical vibration etc. In this paper, for minimization of mechanical vibration, the optimal PM shape is designed and the effect of the circulating current in shorted turns on the demagnetization of PM and motor performance is analyzed. For this analysis, this paper developed a FE-based simulation model with a stator turn fault modeling. The demagnetization phenomenon in IPM type BLDC is analyzed under continuously controlled 3-phase input current considering the circulating current in shorted turn using the developed transient analysis method.

Characteristic analysis of IPM type BLDC motor considering the demagnetization of PM by stator turn fault

A novel permanent-magnet-assisted switched reluctance motor (SRM) having small excitation poles, where phase coils are concentrically wound on the poles and thin permanent magnets are inserted inside the poles, is proposed in this paper. This magnetic structure is feasible due to no flux reversals in the stator by means of large stator poles (hereinafter referred to as common poles) that do not have copper windings or permanent magnets. The insertion of permanent magnets into the stator excitation poles has a significant influence on positive torque improvement leading to a boost in efficiency. Three key design parameters such as the thickness of permanent magnets, space between two adjacent permanent magnets, and the width of stator excitation poles are determined during a design procedure in terms of the enhancement of positive torque. Step-by-step design optimization has been analytically conducted by means of static torque comparison along with dynamic efficiency estimation. The first prototype from its stator and rotor laminations up to physical assembly has been built up.

Novel permanent-magnet-assisted switched reluctance motor (II): Concept, design, and analysis

Since MgB2 superconductor was discovered by Akimitsu, many scientists has been studied this new intermediate temperature superconductor material. Recently Dou reported the critical current density and flux pinning of MgB2 is enhanced by doping of SiC nano powder, and Fujii reported MgB2 superconductor made by the powder-in-tube in-situ process using MgH2 as a precursor powder enhanced the critical current density especially under high magnetic field. Also Matsumoto reported the irreversibility field of MgB 2 tape prepared by the in-situ powder in tube process using MgH2 as a precursor powder increased to 23 T by the SiC doping. These results show MgB2 has high potential as a strong candidate for a practical use. We study the effects of doping nano carbon impurity because graphite has the same structure as the hexagonal Boron structure in MgB2. We added carbon impurities of graphite, C60, and open-ended carbon nano tube respectively to MgB2 conductors made by powder in tube ex-situ process

Jin Hur

Papers

Analysis and Design of Slotted Tubular Linear Actuator for the Eco-Pedal System of a Vehicle

Analysis of single-phase line-start permanent-magnet motor considering iron loss and parameter variation with load angle

Characteristic analysis of IPM type BLDC motor considering the demagnetization of PM by stator turn fault

Novel permanent-magnet-assisted switched reluctance motor (II): Concept, design, and analysis

Properties of $rm MgB_2$ Superconductor by Doping Impurity of SiC, Graphite, $rm C_60$ , and C Nano-Tube