Seong-Jeub Jeon

Design and Implementation of Shaped Magnetic-Resonance-Based Wireless Power Transfer System for Roadway-Powered Moving Electric Vehicles

In this paper, the design and implementation of a wireless power transfer system for moving electric vehicles along with an example of an online electric vehicle system are presented. Electric vehicles are charged on roadway by wireless power transfer technology. Electrical and practical designs of the inverter, power lines, pickup, rectifier, and regulator as well as an optimized core structure design for a large air gap are described. Also, electromotive force shielding for the electric vehicle is suggested. The overall system was implemented and tested. The experimental results showed that 100-kW power with 80% power transfer efficiency under 26-cm air gap was acquired.

A zero-voltage and zero-current switching full bridge DC-DC converter with transformer isolation

A new primary-side-assisted zero-voltage and zero-current switching full bridge DC-DC converter with transformer isolation is proposed. The proposed DC-DC converter uses only one auxiliary transformer and two diodes to obtain ZCS for the leading leg. It has a simple and robust structure, and load current control capability even in short circuit conditions, The possibility of magnetic saturation due to asymmetricity of circuits or transient phenomena is greatly reduced, which is a very attractive feature in DC-DC converters with transformer isolation. The power rating of the auxiliary transformer is about 10% of that of the main transformer. Operation of a 12 kW prototype designed for welding application was verified by experiments.

Contactless power transfer systems for On-Line Electric Vehicle (OLEV)

In this paper, we introduced the overall On-Line Electric Vehicle (OLEV) system and two types of contactless power transfer systems in the OLEV system. Simulation and experimental results for the two types of the systems are given and prototypes of the system constructed are tested.

Definitions of apparent power and power factor in a power system having transmission lines with unequal resistances

Recently, disputes in power theory seem to be settled and a new trial-use standard has been prepared as the IEEE Standard 1459-2000. However, since uniform line resistances are assumed, it is not enough not only for increasing transmission systems, such as parallel ac/dc systems, but for a three-phase four-wire system whose neutral line has a different thickness from the other lines. In this paper, a generalized power theory applicable to a system having transmission/distribution lines with unequal resistances is proposed, which is applicable to any kind of power system: from a single-phase system to a multiline system having transmission lines with equal or unequal resistances under asymmetric and/or nonsinusoidal conditions.

Hybrid inverter segmentation control for Online Electric Vehicle

This paper develops the idea of inverter segmentation control for inductively coupled power transfer system. We propose an hybrid controller which control both Silicon Controlled Rectifier(SCR) and Insulated Gate Bipolar Transistor(IGBT) for steady state response and transient response respectively. With proposed controller, we can achieve high power and high speed track segmentation performance. We applied this method for power source of Online Electric vehicles(OLEV) system. With Proposed method, we could achieve segmentation time less than 100 millisecond(ms) and prevent faults due to output overcurrent.

Reactive power compensation in a multi-line system under sinusoidal unbalanced conditions

A new generalized reactive power compensation algorithm applicable to a multi-line system under sinusoidal conditions is reviewed. This method does not require any decomposition of reactive power or non-active current. It is shown that a realization of the compensator can be obtained by means of a simple connection of reactive elements. Accordingly, it is concluded that to compensate the reactive power is a simple circuit synthesis problem. The algorithm is illustrated by means of examples. Copyright

Considerations on a reactive power concept in a multiline system

The concepts of reactive power that originate from Buchholzs theory and are present in the IEEE Standard 1459 are important in compensation theory. It is shown in this paper that some misconceptions are present in the technical literature, in particular regarding the relationship between reactive power and power oscillation. In this paper, a number of examples are given to illustrate these misconceptions.

Design of a regulator for multi-pick-up systems through using current offsets

In this paper, we introduce a novel regulator for the On-Line Electric Vehicle (OLEV) system and an algorithm of the regulator controller. The OLEV has five pick-ups. The regulator has ten boost converter modules which use dual Proportional Integral (P-I) controllers controlling the output voltage of the modules. This regulator also keeps a balance between the 1st pick-up coils rectified current and the 2nd pick-up coils rectified current and a balance between the 1st pick-up coils rectified voltage and the 2nd pick-up coils rectified voltage. According to the Pulse Width Modulation (PWM) interleaving technique, the output current ripple and the output voltage ripple of the modules are minimized. Using the proposed regulator, we can achieve the stable and high output voltage suitable for battery charging.

Unification and Evaluation of the Instantaneous Reactive Power Theories

The instantaneous reactive power (IRP) theory proposed by Akagi and his coauthors is widespread. When applied to a three-phase four-wire system, two types of IRP theories are available: the original and the modified IRP theory. However, there are ambiguities about which is right between the original and the modified theory and what is wrong. In this paper, a unified IRP theory is proposed, in which unequal resistances of transmission lines are taken into account and those ambiguities are clarified. The original IRP theory provides the spatial optimal solution when the neutral line has infinite resistance, and the modified IRP theory when the neutral line has zero resistance. The unified IRP theory proposed in this paper always provides the spatial optimal solution and includes the original and the modified IRP theory.

Three control strategies for a three-leg AC-DC converter under unbalanced AC voltage condition

Three control strategies that can be applied to a three-phase AC-DC converter under unbalanced input voltage condition are discussed. Analytic solutions are given on the a-b-c frame, and are very simple, direct and intuitive. All of the strategies guarantee sinusoidal input currents. The first strategy maintains unity input power factor per phase, the second one maintains constant instantaneous power, and the last one supplies maximum power within the current rating of the converter. One or more strategies can be chosen according to the situation. All the control functions, including decoupled current control and PWM, are implemented on the a-b-c frame. It is shown that most modern PWM schemes can be realized in the time domain, namely on the a-b-c frame, by slightly modifying SPWM. Accordingly, the controller is very simple and robust. The proposal is verified by simulation and experiments on a prototype operating at 15 kHz.