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>

Forecasting Day-ahead Electricity Price Using a Hybrid Improved Approach

Hu, Jian-Ming,Wang, Jian-Zhou The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.6

Electricity price prediction plays a crucial part in making the schedule and managing the risk to the competitive electricity market participants. However, it is a difficult and challenging task owing to the characteristics of the nonlinearity, non-stationarity and uncertainty of the price series. This study proposes a hybrid improved strategy which incorporates data preprocessor components and a forecasting engine component to enhance the forecasting accuracy of the electricity price. In the developed forecasting procedure, the Seasonal Adjustment (SA) method and the Ensemble Empirical Mode Decomposition (EEMD) technique are synthesized as the data preprocessing component; the Coupled Simulated Annealing (CSA) optimization method and the Least Square Support Vector Regression (LSSVR) algorithm construct the prediction engine. The proposed hybrid approach is verified with electricity price data sampled from the power market of New South Wales in Australia. The simulation outcome manifests that the proposed hybrid approach obtains the observable improvement in the forecasting accuracy compared with other approaches, which suggests that the proposed combinational approach occupies preferable predication ability and enough precision.

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>

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>

Multi-Objective Optimization Model of Electricity Behavior Considering the Combination of Household Appliance Correlation and Comfort

Qu, Zhaoyang,Qu, Nan,Liu, Yaowei,Yin, Xiangai,Qu, Chong,Wang, Wanxin,Han, Jing The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

With the wide application of intelligent household appliances, the optimization of electricity behavior has become an important component of home-based intelligent electricity. In this study, a multi-objective optimization model in an intelligent electricity environment is proposed based on economy and comfort. Firstly, the domestic consumer's load characteristics are analyzed, and the operating constraints of interruptible and transferable electrical appliances are defined. Then, constraints such as household electrical load, electricity habits, the correlation minimization electricity expenditure model of household appliances, and the comfort model of electricity use are integrated into multi-objective optimization. Finally, a continuous search multi-objective particle swarm algorithm is proposed to solve the optimization problem. The analysis of the corresponding example shows that the multi-objective optimization model can effectively reduce electricity costs and improve electricity use comfort.

A Diesel Generator Model with Fluctuating Engine Torque Including Magnetic Saturation for Transient Analysis using XTAP

Sakamoto, Orie The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Diesel engine generators are widely used in the world, especially in remote site power systems as distributed generators. A weak distribution feeder with a small diesel engine may suffer from voltage and power fluctuations due to misfiring of the engine cylinder. In this study, new generator model with example engine torque was developed for the electromagnetic transient analysis program for power systems named XTAP. The configuration and verification results of the developed model are presented in the paper. The model is considered to be useful for analyses of small power systems with those diesel engines.

Design and Control of an Optimized Battery Charger for an xEV Based on Photovoltaic Power Systems

Kim, Dong-Hee,Cheo, Gyu-Yeong,Lee, Byoung-Kuk The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.5

The continuous growth of electric vehicles has caused electric power shortages in conventional utilities owing to the charging of electric-vehicle batteries. In order to increase the capacity of these utilities, photovoltaic systems may be an appropriate solution because of their benefits. However, a large amount of loss is generated in a conventional charging structure using photovoltaic sources owing to the many power conversion processes. This paper describes a simple integrated battery charger that utilizes a PV generation system. Moreover, the system control algorithm is deduced by analyzing the operation modes in order to control the proposed integrated system. The proposed system and algorithm are verified by a 3.3-kW prototype, resulting in an increase in the efficiency of approximately 7% to 15% compared with the conventional system. And, to examine the feasibility of the proposed system, the simulation for multi-charger with various conditions are progressed.

Calculation on the Ion Flow Field under HVDC Transmission Lines Considering Wind Effects

Wu, Jing,Gao, Sheng,Liu, Yuxiao The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.5

Based on Deutsch assumption, a calculation method on the electric field over the ground surface under HVDC transmission lines in the wind is proposed. Analyzing the wind effects on the electric field and the space charge density the existing method based on Deutsch assumption is improved through adding the wind speed to the ion flow field equations. The programming details are illustrated. The calculation results at zero wind speed are compared with available data to validate the code program. Then the ionized fields which resulted from corona of ±800kV HVDC lines are analyzed. Both the electric field and the current density on the ground level are computed under different wind direction and speed. The computation results are in good agreement with measurements. The presented method and code program can be used to rapidly predict and evaluate the wind effects in HVDC transmission engineering.

A Study on New Power Business Model Using Power Information Technology

Bae, Sung-Hwan,Kim, Ja-Hee,Lim, Han-Seung The Korean Institute of Electrical Engineers 2010 Journal of Electrical Engineering & Technology Vol.5 No.3

The Korea Electric Power Corporation (KEPCO) recorded 2.9 trillion won deficit in the aftermath of the world financial crisis. KEPCO is trying to escape from the business crisis in every way; however, it is impossible to make huge profit by selling electricity alone. Overseas electrical utilities make profits by selling gas and heat along with electricity. However, it is difficult for KEPCO to enter the gas and the heat selling market because other public companies are already dealing with them. In this situation, improving the business is possible when KEPCO develops a new business model and creates added value using Korean advanced Power IT combined with electricity. This study shows a new business model using Power IT, based on a survey targeting managers in KEPCO branch office and electrical engineers in the field. We hope the new business model suggested in this study is adapted to the real field to create high value in the future.