Patterns of Plasma Bullet in Plasma Jets

Gook Hee Han,Je Huan Koo,Duk In Choi,Eun Ha Choi,Guangsup Cho Institute of Electrical and Electronics Engineers 2015 IEEE transactions on plasma science Vol. No.

<P>Composite charges applied to plasma striations were investigated through this paper. Bullets in plasma jets stemming from effective electrons made up of a moving target electron with screening electrons and ions around it were assessed using an atom-like structure induced by an external electric or magnetic field. To maintain a zero total charge, screening electrons and ions were assumed to be spherically and symmetrically distributed around a target moving electron -e, and the surrounding -e or +e was equivalent to the composition of an electric field vortex and an electron. Electrons moving around a spherical orbit were found to have positive charges under a strong electric field but negative charges under a weak field, mainly because the cross-sectional area of the flux was very small. In plasma jets, striations are a phenomenon that may occur when charges gather in the presence of an electric or gauge field. A plasma striation can occur if the effective charge exceeds a critical value determined by setting the derivative of the effective charge to zero, but only if the electric field lines passing through the striation are connected.</P>

Comprehensive Electric-Thermal Photovoltaic Modeling for Power-Hardware-in-the-Loop Simulation (PHILS) Applications

Xuan Hung Mai,Sang-Kyu Kwak,Jee-Hoon Jung,Kim, Katherine A. Institute of Electrical and Electronics Engineers 2017 IEEE transactions on industrial electronics Vol.64 No.8

<P>This paper presents a dynamic, electricthermal model for a photovoltaic (PV) cell that combines electrical and thermal parameters to accurately emulate PV panels in real time for power-hardware-in-the-loop simulation (PHILS). In this model, the irradiance and ambient temperature are used to calculate the PV cell temperature based on a five-layer thermal model. The cell temperature is then used in the electrical model to accurately adjust the PV electrical characteristics. A custom experimental setup is built to test and verify the electrical and thermal characteristics of the PV cell model. This electric-thermal model is validated using experimental data in realistic scenarios. The model is also tested with PHILS using a real-time simulator and a programmable dc power supply to emulate PV power generation under various load changes. The model is well matched to the experimental measurements with an error within 2.4% for the electrical aspects and within 1.5% for the thermal aspects in the tested scenarios.</P>

Self-Excited Induction Generator as an Auxiliary Brake for Heavy Vehicles and Its Analog Controller

Jae-Nam Bae,Yong-Eun Kim,Young-Wook Son,Hee-Seok Moon,Chang-Hee Yoo,Ju Lee Institute of Electrical and Electronics Engineers 2015 IEEE transactions on industrial electronics Vol. No.

<P>A self-excited induction generator (SEIG) can be a candidate for isolated applications because it does not require any external exciting power but can independently generate electricity. It is also a good candidate for auxiliary brakes in heavy vehicles for several reasons. First, the power efficiency in a brake system is not important as compared with motors or generators. Second, an SEIG can be controlled by a simple electrical circuit. Third, it can be used for regenerative braking. Finally, it is very robust. In this paper, an auxiliary brake for heavy vehicles is proposed by adapting an SEIG and its analog control circuit. The brake structure is the same as that in conventional eddy current brakes but operates as an SEIG. The suggested control circuit does not adopt an electric controller unit but only consists of simple electric devices. A miniature model was designed and manufactured, and the experimental results using the prototype verify that the proposed brake system, including the controller, is very useful.</P>

Copper thin films on PET prepared at ambient temperature by ECR-CVD

Ko, Hyungduk,Jhin, J.,Byun, Dongjin,Lee, Joongkee,Park, D. Institute of Electrical and Electronics Engineers, 2005 IEEE transactions on components and packaging tech Vol.28 No.4

Metallized polymers were prepared at ambient temperature by an electron-cyclotron-resonance (ECR) chemical vapor deposition system equipped with (-) DC bias from the Cu (hfac)<SUB>2</SUB>-Ar-H<SUB>2</SUB> system. X-ray difraction (XRD) results showed that the Cu (111) peaks were clearly observed when H<SUB>2</SUB> was introduced to the plasma. The surface morphology showed that larger Cu grains were formed in the metal-organic composite films with the introduction of H<SUB>2</SUB> to the plasma. AES depth profiles showed that H<SUB>2</SUB> gas introduction to the plasma led to the formation of copper-rich films with a homogeneous composition. Also, the sheet resistance was strongly dependent on the H<SUB>2</SUB> content of the plasma. This means that hydrogen may lead to both the formation of stable volatile organic compounds and the reduction of copper, which influences both the crystallographic structure and the composition of films. As a result, crystalline copper films with a sheet resistance of 2-3Ω<SUP>2</SUP> can be prepared on poly ethylene terephthalate with the addition of H<SUB>2</SUB> to the plasma.

Electric-Circuit-Embedded Polymer Optical Bench

Kim, Jin Tae,Ju, Jung Jin,Park, Suntak,Park, Seung Koo,Kim, Min-Su,Lee, Myung-Hyun Institute of Electrical and Electronics Engineers 2007 IEEE photonics technology letters Vol.19 No.5-8

<P>In order to overcome the shortcomings of silicon optical bench with surface-patterned electric circuits, an electric-circuit-embedded polymer optical bench was developed. The main design issue was to embed the electric circuit under the optical bench and to let the electric contact pads be opened at the bottom of the alignment pits. To accommodate the surplus conductive adhesive, adhesive-fill space was created at the alignment pits. This architectural invention provides not only more efficient fiber-chip coupling of the planar-lightwave-circuit-type optical waveguide device but also a good electrical contact. An upside-down mounted single-mode waveguide chip showed a coupling loss of about 0.9 dB per coupling face with a single-mode fiber at a wavelength of 1.5 mum</P>

Robust Air-to-Fuel Ratio and Boost Pressure Controller Design for the EGR and VGT Systems Using Quantitative Feedback Theory

Inseok Park,Seungwoo Hong,Myoungho Sunwoo Institute of Electrical and Electronics Engineers 2014 IEEE transactions on control systems technology Vol. No.

<P>This paper describes robust multi-input, multi-output controller for the exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT) systems of passenger car diesel engines. The air-to-fuel ratio of the exhaust gas and boost pressure of the intake manifold were selected as performance indicators in this paper. To enable the online calibration of the controller, proportional-integral-derivative (PID) was used as a feedback controller. Using quantitative feedback theory (QFT), two control loops for air-to-fuel ratio and boost pressure were independently designed with linearized models and parameter uncertainties. The prefilters and PID gains of two control loops were designed for satisfying required robust stability and tracking performance using the QFT design framework. Furthermore, the problems originated from the cross-coupled dynamics between the EGR and VGT systems were mitigated by a static decoupler. Using the proposed design steps, PID and decoupler gains of the representative 15 engine operating points which are mainly used in New European Driving Cycle were obtained. The proposed controller was validated through various test conditions of engine experiments. From the step responses and transient experiments, it was demonstrated that the required robustness and tracking performance were successfully achieved.</P>

Raman Scattering Studies of <tex> ${\rm YBa}_{2}{\rm Cu}_{3}{\rm O}_{7-{\rm x}}$</tex> Films Grown by High-Rate e-Beam Co-Evaporation

Lee, E.,Yoon, H.R.,Jo, W.,Yoon, S.,Cheong, H.,Lee, H.G.,Hong, G.W.,Huh, J.U.,Hammond, R.H.,Beasley, M.R. Institute of Electrical and Electronics Engineers 2007 IEEE transactions on applied superconductivity Vol.17 No.2

<P>We present results of Raman scattering studies of superconducting YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-x</SUB> (YBCO) films grown by a high-rate electron-beam co-evaporation method. It is shown by X-ray diffraction that the as-grown YBCO films have a highly c-axis oriented and in-plane aligned texture. Raman scattering measurements were used to study optical phonon modes, oxygen content and second phases of the YBCO coated conductors. Raman spectra of YBCO films with lower-transport properties exhibit additional phonon modes at ~ 300 cm<SUP>-1</SUP>, ~ 600 cm<SUP>-1</SUP>, and ~ 630 cm<SUP>-1</SUP>, which are related to second-phases such as Ba<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>5.9</SUB> and BaCuO<SUB>2</SUB>. We also performed micro-Raman scattering measurements, which enable the local characterization of the material over a few micrometer scales. We could clearly determine the chemical homogeneities of the films on which we could not have information using XRD. Our results strongly suggest that micro-Raman scattering can be a very effective tool for characterizing structural and chemical properties, which is essential for optimizing growth conditions.</P>

Exhaust Pressure Estimation for Diesel Engines Equipped With Dual-Loop EGR and VGT

Kim, Sooyoung,Jin, Hyomin,Choi, Seibum B. Institute of Electrical and Electronics Engineers 2018 IEEE transactions on control systems technology Vol.26 No.2

<P>This paper describes an observer design method that estimates the exhaust manifold pressure in a diesel engine with limited sensor information. In the modern model-based control of air flows, information on the exhaust pressure is often necessary for control stability. However, it is not easy to measure the exhaust pressure with sensors due to the unfavorable environment for measurement and the high cost of sensors. Therefore, a robust observer, which is applicable to engines equipped with a dual-loop exhaust gas recirculation (EGR) system and a variable geometry turbine, is designed to estimate the exhaust pressure. The observer takes the form of a Luenberger-sliding mode observer in order to guarantee its asymptotic stability upon consideration of the model uncertainties. For research on state estimation and control of dual-loop EGR engines, information on the pressure states in the low pressure EGR loop must be provided. Hence, this paper also proposes an intuitive regression modeling method for the pressure states of the compressor inlet and turbine outlet with physical insights into the engine operation. Applying the regression models to the observer algorithm, the estimation performance of the exhaust pressure observer is verified experimentally in both steady state and transient conditions with a 6-L heavy-duty diesel engine.</P>

Operational Characteristics of a Small-Scale Novel Hybrid Resistive-Type SFCL With Controlled Power Electronics

Nam, Seokho,Lee, Jiho,Lee, Woo Seung,Park, Young Gun,Song, Seunghyun,Jin, Hongwoo,Ko, Tae Kuk Institute of Electrical and Electronics Engineers 2015 IEEE transactions on applied superconductivity Vol.25 No.3

<P>As electric power systems become more complicated, the fault current experiences more frequent changes. To solve this problem, we suggest a novel hybrid-type superconducting fault current limiter (SFCL). Some issues accompany application of resistive-type SFCLs to electric power systems, including initial installation price, operation and maintenance costs, and high-current problems. To overcome these problems, <I>hybrid SFCLs </I> have been developed in some institutions. This paper presents experimental tests of a novel hybrid-type SFCL composed of a resistive superconducting coil, two thyristors, and a control circuit. The superconducting coil limits the first peak of the fault current, and the thyristors control the magnitude of the fault current other than the first peak by adjusting the firing angles. The interactions between the superconducting coil and the thyristors reduce the use of superconducting wire.</P>

Design Method of an Ultrahigh Speed PM Motor/Generator for Electric-Turbo Compounding System

Jung, Dong-Hoon,Lee, Jae-Kwang,Kim, Jun-Young,Jang, Ik Sang,Lee, Ju,Lee, Ho-Joon Institute of Electrical and Electronics Engineers 2018 IEEE transactions on applied superconductivity Vol.28 No.3

<P>This paper presents the design of an ultrahigh speed permanent magnet (PM) motor/generator driven at a rated output and speed of 10 kW and 70 000 r/min, respectively, for use in an electric-turbo compounding system. When designing the very-high speed motor/generator, the mechanical and structural safety of the rotor and losses that occur when the motor operates at high speed should be considered for safe operation. In this paper, the optimal design of the ultrahigh speed PM motor is performed with finite element analysis and structural analysis. Especially, the electromagnetic and structural characteristics based on the sleeve material are analyzed. The optimal design for PM motor, using carbon fiber is proposed not only to reduce the eddy-current loss, which prominently occurs at very-high speed, but also to ensure its structural safety. Finally, the validity of the design method and the effectiveness of the fabricated prototype of PM motor is verified through experimental tests.</P>