Yangsu Kim

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.

Design of a high power transfer pickup for on-line electric vehicle (OLEV)

Recent electric vehicle technology with battery has faced many problems: high cost, weight, driving distance, long charging time and danger of electric shock. An inductive power transfer pickup for electric vehicles such as pickup of traditional transformer enables electric vehicles to overcome these problems by using contactless power transfer. Also, inductive power transfer pickup has many advantages including high efficiency, high power, a large air gap and lightweight. In this paper, proposed inductive power pickup was developed using series capacitor with ferrite cores and multi-windings and was tested for its ability to transfer electricity wirelessly. When tested for output power and efficiency of pickup, output power of 20kW and efficiency of 86.7% were achieved at 20 kHz and 250mm air gap.

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.

High efficient Inductive Power Supply and Pickup system for On-Line Electric Bus

The IPSP(Inductive Power Supply and Pickup) system for the On-Line Electric Bus that can pickup inductive power from underground coils with high power efficiency has been developed recently and is now proposed in this paper. The presented IPSP system consists of four parts, that is, power inverter, road embedded rail, pickup module and a regulator. From the experiment of the proposed system, we obtained above 80% of total power transfer efficiency from three phase AC input of power inverter to DC output voltage of regulator with 100kW rated output power. In this case, the gap between road and the bottom side of pickup module was 200mm.

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.

The optimal design of high-powered power supply modules for wireless power transferred train

In this paper, the wireless power transfer technology is applied to the high-powered train system. Through applying wireless power transfer technology, many defects of original train system (wired power transfer) can be overcome. The optimal design of power supply module for wireless power transfer system is required to make a 100kW power supply. Three approaches for deciding optimal design of power supply module are discussed. Three approaches are on about induced voltage of pick-up modules in various size of power supply, heat generation due to the magnetic flux from primary coil and types of the power supplying cables. Coupled simulations about magnetic-heat transfer and electrical experiments are conducted.

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.

Wireless charging system for On-Line Electric Bus(OLEB) with series-connected road-embedded segment

Wireless charging system for On-Line Electric Bus(OLEB) consists of power inverter, road embedded rail, pickup module and regulator, which have been developed by KAIST several years ago. In this paper, wireless charging system for OLEB with series-connected road embedded segment structure is suggested to implement small-sized power inverter which is easier and cheaper to install near the bus stop. The experimental results are obtained from the experimental setup, from which the applicability of the proposed system is verified through experimental results.

Design of buried power line for roadway-powered electric vehicle system

In this paper, we introduce Online Electric Vehicle (OLEV) system which is a roadway-powered electric vehicle system, and explain the design of power lines under the road. More specifically, cost-effective power line design for roadway-powered electric vehicle system is proposed. Simulation and experimental results for validation of the proposed system are given.

Wireless power transfer system for high power application and a method of segmentation

This paper develops the idea of wireless power transfer system for high power application. We proposed power supply system, power reciever system and its intergration. We assembly six supply and reciever pairs to obtain high power output using proposed resonance compensation. we verified proposed system by simulation and experiment. We were able to transfer 490kW over 11cm air gap. We discuss the practical applicability of this system and suggest directions for further study.