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.

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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 represents the force performance of a brushless dc motor with a continuous ring-type permanent magnet (PM), considering its magnetization patterns: trapezoidal, trapezoidal with dead zone, and unbalanced trapezoidal magnetization with dead zone. The radial force density in PM motor causes vibration, because vibration is induced the traveling force from the rotating PM acting on the stator. Magnetization distribution of the PM as well as the shape of the teeth determines the distribution of force density. In particular, the distribution has a three-dimensional (3-D) pattern because of overhang, that is, it is not uniform in axial direction. Thus, the analysis of radial force density required dynamic analysis considering the 3-D shape of the teeth and overhang. The results show that the force density as a source of vibration varies considerably depending on the overhang and magnetization distribution patterns. In addition, the validity of the developed method, coupled 3-D equivalent magnetic circuit network method, with driving circuit and motion equation, is confirmed by comparison of conventional method using 3D finite element method.

Performance analysis of a brushless dc motor due to magnetization distribution in a continuous ring magnet

This paper is analyzed on back electromotive force harmonic characteristic in interior permanent magnet type brushless DC motors according to demagnetization patterns. Demagnetization patterns consist of equality, inequality, and weighted demagnetization. In addition, we used the same pole-slot ratio with different pole-slot numbers models and different pole-slot ratio with different pole-slot numbers model. Furthermore, we performed analysis of flux linkage, back electromotive force, and harmonics of back electromotive force according to demagnetization patterns. In conclusion, we propose detection technique of irreversible demagnetization condition using back electromotive force harmonics characteristic of an interior permanent magnet type brushless DC motors.

BEMF characteristic analysis of IPM type motor according to demagnetization pattern of permanent magnet

In this article, in order to enhance the performance of Hall-ICs, a position signal synthesize control algorithm is developed. Also, considering diagnosis of permanent magnet brushless DC (PM BLDC) motor control and safety operation or system protection in case of having trouble and fault in one of Hall-ICs during operation, the developed two Hall-IC control scheme is applied. With the position signal of phase lock loop (PLL) control algorithm and the remainder scheme, one can operate the slotless PM BLDC motor in high performance.

Implementation of Low Cost and Advanced Slotless Brushless DC Motor Drive Using PLL Algorithm

The loss reduction algorithm for the light-load is needed to increase overall efficiency. The inductor current ripple is the fixed magnitude, and it generates almost loss of the total losses at the light-load. Therefore, the ripple current reduction algorithm is efficient method to increase the light-load efficiency. This letter proposes the control algorithm to increase light-load efficiency by controlling the inductor current ripple. To control the inductor current optimally, a detail analysis of the system and a maximum efficiency control scheme are progressed. From the proposed algorithm, the efficiency is increased about 2.93% at the 10% load condition compared with the conventional algorithm.

Light-load efficiency improving algorithm in cascaded buck-boost converter

In this study, a method for controlling the magnetomotive force using the current bypass of no-insulation magnets was developed, and the characteristics of 1G high-temperature superconductivity (HTS) no-insulation magnets were elucidated through experiments. The experiments were performed using a magnet designed with bismuth strontium calcium copper oxide HTS wires. Film-type heaters were used to control the MMF. The analysis of the experimental results was carried out in conjunction with an analysis using finite elements method.

Jin Hur

Papers

Performance analysis of a brushless dc motor due to magnetization distribution in a continuous ring magnet

BEMF characteristic analysis of IPM type motor according to demagnetization pattern of permanent magnet

Implementation of Low Cost and Advanced Slotless Brushless DC Motor Drive Using PLL Algorithm

Light-load efficiency improving algorithm in cascaded buck-boost converter

Study of Magnetomotive Force Control Type Superconducting Magnet Using BSCCO HTS Wire