Changbyung Park

On-Line Electric Vehicle using inductive power transfer system

In this paper, 3 generations of OLEV (On-Line Electrical Vehicle) are introduced. The 1st generation of OLEV is conventional E-type structure. The air gap of the 1st generation is 1cm and the input to output power efficiency is 80% with 3 kW output power. The ultra slim U-type mono rail structure is applied to the 2nd generation of OLEV. This structure is applied to the OLEV bus which achieves 52 kW output power with 72% efficiency at 17 cm air gap. SUV (Sports Utility Vehicle) equipped with the 3rd generation of OLEV named ultra slim W-type (dual rail structure) accomplished 15 kW/pick-up and 71% efficiency at 17 cm air gap

High performance inductive power transfer system with narrow rail width for On-Line Electric Vehicles

A new inductive power transfer system (IPTS) with narrow rail width and large air-gap for electric vehicle (EV) is proposed in this paper. By a new core structure, the orientation of magnetic flux is alternating along with the road. Hence, the proposed IPTS with narrow rail width, 10 cm, and large air-gap, up to 20 cm, can be implemented for EV. The power supply inverter uses 440 V, 3phase input and supplies 20 kHz output current. To null the high voltages of power rail and pick-up and to transfer maximum power to vehicles, resonant capacitors are inserted to each side of the rail and the pick-up. The test results show that the maximum output power is 35 kW and the maximum efficiency is 74 % at 27 kW output. The proposed IPTS is found to be adequate for EV which can freely drive on the road by picking up the power from the underground power supply rail.

Innovative 5-m-Off-Distance Inductive Power Transfer Systems With Optimally Shaped Dipole Coils

5-m-off-distance inductive power transfer systems that have optimally shaped cores in the primary and secondary coils are proposed. Instead of conventional-loop-type coils for magnetic resonance scheme, magnetic dipole type coils with cores are used for drastic reduction in deployment space and quite long wireless power transfer. An optimized stepped core structure is also proposed, where a strong magnetic field section is so thick that magnetic field density may be even. Thus, the proposed optimized stepped core has only 41% core loss compared with an unoptimized even core but delivers 2.1 times more wireless power for a given amount of core. Experimentally obtained maximum output powers and primary-coil-to-load-power efficiencies for 3, 4, and 5 m at 20 kHz were 1403, 471, 209 W, and 29%, 16%, 8%, respectively.

A highly noise-immune touch controller using Filtered-Delta-Integration and a charge-interpolation technique for 10.1-inch capacitive touch-screen panels

Capacitive touch-screen panels (TSPs) are widely used in recent high-end mobile products on the basis of their high quality of touch features, as well as superior visibility and durability [1-5]. Capacitive TSPs can be classified into self-capacitance [1,2] or mutual-capacitance [3-5] types, according to the sensing mechanism. Compared with the self-capacitance types, which offer low cost and high scan frequency from the simple line-sensing scheme, the mutual-capacitance types, which read out all sensor pixels, are presently widely preferred due to their multi-touch capabilities. However, the reduced sensing time for each sensor makes it difficult to achieve a high signal-to-noise ratio (SNR). Therefore, good noise performance in the analog front-end of the touch controller is essential for mutual-capacitance type TSPs.

Active EMF cancellation method for I-type pickup of On-Line Electric Vehicles

In the Inductive Power Transfer System (IPTS) for the On-Line Electric Vehicle (OLEV), the Electro Magnetic Field (EMF) should be lower than 62.5 mG at 20 kHz for the safety of pedestrians. To meet the EMF requirement a new active EMF cancel method for the recently developed I-type IPTS is proposed in this paper. The I-type IPTS has a narrow rail width structure with alternating magnetic polarity along with a roadway. The EMF canceling is applied to only pick-up where large EMF is generated due to large ampere-turns. An optimum spacing for cancel coils from main coils is found, and an optimum canceling architecture is also proposed. Experiments for various conditions such as cancel coil turns, size, configuration, and rectifier connection verify that the canceling strategy on the IPTS for OLEV proposed in this paper is quite practical. The EMF at 1 m distance from the center of pick-up is always under 50 mG for maximum power condition.

Two-Dimensional Inductive Power Transfer System for Mobile Robots Using Evenly Displaced Multiple Pickups

The inductive power transfer system for mobile robots, which has the single wire layer of easily fabricated power floor structure and the evenly displaced multiple pickup structure for receiving uniform power, is proposed. Due to its simple structure, a wide-area power floor of 3.52 m2 (1.6 m ×2.2 m) could be fabricated as a prototype. Three pickups with evenly displaced angle and space are adopted, considering the limited bottom area of the free-moving mobile robot. The size and position of each pickup are appropriately selected for the given subwinding size of the power floor and magnetic pole arrangement. Experiments for the prototype show that the proposed multiple pickup structure lowers the spatial output power variation and that enough output power of 10 W can be obtained for the mobile robots.

Uniform Power I-Type Inductive Power Transfer System With DQ -Power Supply Rails for On-Line Electric Vehicles

A narrow-width power-invariant inductive power transfer system (IPTS) along the driving direction is newly proposed in this paper. The conventional I-type power supply rail for on-line electric vehicles (OLEVs) has a very narrow power supply rail with 10-cm width and exposes pedestrians to a very low electromagnetic field due to its alternatively arranged magnetic poles along the driving direction of electric vehicles; however, it has a major drawback: Sinusoidal variation of the induced pick-up voltage depending on pick-up positions on the power supply rail along driving direction. To overcome this disadvantage, a dq-power supply rail fed by two high-frequency ac currents of the d-phase and q-phase is introduced in this paper. The d -phase and q-phase magnetic poles are alternatively arranged in a line; hence, the induced voltage of a pickup becomes spatially uniform. The power invariant characteristic of the proposed IPTS for OLEV has been verified by analysis, simulations, and experiments. A practical winding method is suggested as well.

Robust and efficient synchronous buck converter with near-optimal dead-time control

In switching power converters, the turn on/off process of switches is crucial for the reliability and efficiency of the converter. In general, optimum switching is challenging, and it is particularly difficult for hard switching. The MOSFET synchronous buck converter having wide applications due to high switching speed and low loss, however, operates in hard switching and needs a good timing control for its switching. On/off commutation dead-times should be adjusted carefully in accordance with load current change. Previous work on the dead-time control includes predictive gate drive technique [1], load current sensing [2][7], sensor-less optimization technique [3], and delay-locked loops [4–6]. These techniques have problems of sensing noisy switching node [1, 4–6] or load current [2, 7], and requiring high quantizing resolution [3]. In this paper, a near optimum dead-time control method is proposed thate resolves such problems.

5m-off-long-distance inductive power transfer system using optimum shaped dipole coils

The 5m-off-long-distance inductive power transfer system which has optimum shaped core in the primary and secondary coils is proposed. Instead of conventional loop type coils for magnetic resonance scheme, magnetic dipole type coils are used for drastic reduction in deployment space but providing quite longer field distribution. The core has stepped structure, where strong magnetic field section is thicker than weak one. Practical issues such as winding method, minimizing eddy current loss, and the selection of capacitor type are considered. The measured maximum output powers were 1,403 W, 471 W, and 209 W for 3m, 4m, and 5m, respectively. Maximum primary coil to load power efficiencies at 20 kHz were about 50%, 30%, and 16% for 3m, 4m, and 5m, respectively.

Static and dynamic analyses of three-phase rectifier with LC input filter by laplace phasor transformation

The phasor transformation applicable only to the static analysis of linear AC converters so far has been extended to the dynamic analysis in this paper. A complex LT (Laplace transformation) is newly adopted for the dynamic analysis of phasor transformed circuits. It is verified in general that any linear AC converter can be completely analyzed of closed form by the proposed transformation. A pseudo real Laplacian concept is proposed to deal with the delicate real part operation that appears in the phasor circuits of inverters or rectifiers, where conventional LT cannot be applied. The system stability of a time-varying AC converter in time domain is proved to be the same as that in complex frequency domain. A 7th order three-phase rectifier, degenerated to a 3rd order system, was fully analyzed and verified by simulations with great simplicity compared with the conventional D-Q transformation.