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

A 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. 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 modification and a comparison between the proposed permanent-magnet-assisted SRM and no-permanent-magnet SRM have been conducted by means of static torque comparison along with dynamic performance. The first prototype from steel laminations up to its physical assembly has been constructed.

http://koreascience.or.kr:80/article/JAKO201433150758379.pdf

Design and Analysis of a Permanent-Magnet-Assisted Switched Reluctance Motor

This paper presents the development of a 4.0 mm- outer-diameter permanent magnet (PM) type stepping motor with a newly structured claw-poles. We propose a novel structure for a 4.0 mm-outer-diameter (O.D.) PM type stepping motor. Magnetic characteristics are analyzed compare to the general type one using the three-dimensional finite element analysis (3-D FEA) account for magnetization of PM. From the analysis and experimental results of them, we confirmed that the proposed model is available of miniaturization.

Development of a 4.0mm-outer-diameter PM type stepping motor with a newly structured claw-poles

Design of SPOKE Type BLDC Motor for Traction Application Considering Irreversible Demagnetization of Permanent Magnet

In this study, we investigate the irreversible demagnetization of a permanent magnet brushless DC motor under the stator turn fault conditions. We analyze the magnetic distribution property, input current, circulating current, and demagnetization characteristic of PM. For this transient analysis, we develop an FEM-based demagnetization algorithm under operating state, taking into account the circulating current flowing in the shorted turns and freewheeling current flowing in the diode. This analysis results from demagnetization algorithm are verified by performing an experiment.

Transient analysis of irreversible demagnetization of permenent magnet brushless DC motor with stator turn fault under the operating state

In this paper, we analyze the back electromotive force (BEMF) characteristics according to the magnetization pattern of irreversible demagnetization to determine the fault type for interior permanent-magnet (IPM) type brushless DC (BLDC) motors. We numerically model irreversible demagnetized PMs using space-harmonics analysis. In addition, we analyze the results using the finite element and analytical methods. Demagnetization can be predicted by performing mathematical analyses using space harmonics. We then experimentally verify the harmonic characteristics of a test motor. Finally, we propose an irreversible demagnetization diagnosis technique for IPM-type BLDC motors using the harmonic characteristics of the BEMF.

Jin Hur

Papers

Design and Analysis of a Permanent-Magnet-Assisted Switched Reluctance Motor

Development of a 4.0mm-outer-diameter PM type stepping motor with a newly structured claw-poles

Design of SPOKE Type BLDC Motor for Traction Application Considering Irreversible Demagnetization of Permanent Magnet

Transient analysis of irreversible demagnetization of permenent magnet brushless DC motor with stator turn fault under the operating state

Irreversible demagnetization diagnosis of IPM-type BLDC motor using BEMF harmonic characteristics based on space harmonics