• Journal of the Microelectronics and Packaging Society
• /
• v.21 no.4
• /
• pp.1-13
• /
• 2014

The paper gives an overview of the concepts, basic requirements, and trends regarding packaging technologies of power modules in hybrid (HEV) and electric vehicles (EV). Power electronics is gaining more and more importance in the automotive sector due to the slow but steady progress of introducing partially or even fully electric powered vehicles. The demands for power electronic devices and systems are manifold, and concerns besides aspects such as energy efficiency, cooling and costs especially robustness and lifetime issues. Higher operation temperatures and the current density increase of new IGBT (Insulated Gate Bipolar Transistor) generations make it more and more complicated to meet the quality requirements for power electronic modules. Especially the increasing heat dissipation inside the silicon (Si) leads to maximum operation temperatures of nearly $200^{\circ}C$. As a result new packaging technologies are needed to face the demands of power modules in the future. Wide-band gap (WBG) semiconductors such as silicon carbide (SiC) or gallium nitride (GaN) have the potential to considerably enhance the energy efficiency and to reduce the weight of power electronic systems in EVs due to their improved electrical and thermal properties in comparison to Si based solutions. In this paper, we will introduce various package materials, advanced packaging technologies, heat dissipation and thermal management of advanced power modules with extended reliability for EV applications. In addition, SiC and GaN based WBG power modules will be introduced.

• Journal of IKEEE
• /
• v.18 no.4
• /
• pp.471-477
• /
• 2014

In this paper, we propose a low-cost license plate recognition system based on smart cam system using Android. The proposed system consists of a portable device and server. Potable device Hardware consists of ARM Cortex-A9 (S5PV210) processor control unit, a power supply device, wired and wireless communication, input/output unit. We develope Linux kernel and dedicated device driver for WiFi module and camera. The license plate recognition algorithm is consisted of setting candidate plates areas with canny edge detector, extracting license plate number with Labeling, recognizing with template matching, etc. The number that is recognized by the device is transmitted to the remote server via the user mobile phone, and the server re-transfer the vehicle information in the database to the portable device. To verify the utility of the proposed system, user photographs the license plate of any vehicle in the natural environment. Confirming the recognition result, the recognition rate was 95%. The proposed system was suitable for low cost portable license plate recognition device, it enabled the stability of the system when used long time by using the Android operating system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.10
• /
• pp.15-23
• /
• 2017

This paper reports a SOC(State-of-Charge) estimation method using the extended Kalman filter(EKF) algorithm, which can allow real-time implementation and reduce the error of the model and be robust against noise, to accurately estimate and evaluate the charging/discharging state of the EV(Electric Vehicle) battery. The battery was modeled as the first order Thevenin model for the EKF algorithm and the parameters were derived through experiments. This paper proposes the changed method, which can have the SOC to 0% ~ 100% regardless of the aging of the battery by replacing the rated capacity specified in the battery with the maximum chargeable capacity. In addition, This paper proposes the EKF algorithm to estimate the non-linearity interval of the battery and simulation result based on Ah-counting shows that the proposed algorithm reduces the estimation error to less than 5% in all intervals of the SOC.

• Journal of the Korean Electrochemical Society
• /
• v.11 no.3
• /
• pp.197-210
• /
• 2008

The cathode materials for lithium ion battery have been developed in accordance with the battery performance. $LiCoO_2$ initially adapted at lithium ion battery is going to be useful even at the charging voltage of 4.3 V by surface treatment or doping which drastically improved the performance of $LiCoO_2$. On the other hand, the complicate and multiple functions of recent electronic equipments required higher operational voltage and higher capacity than ever, which is going to be driving force for developing new cathode materials. Some of them are $LiNi_{1-x}{M_xO_2}$, $Li[Ni_{x}Mn_{y}Co_{z}]O_{2}$, $Li[{Ni}_{1/2}{Mn}_{1/2}]O_{2}$. Other new type of cathode materials having high safety is also developed to apply for HEV (hybrid electrical vehicle) and power tool applications. ${LiMn}_{2}{O}_{4}$ and $LiFePO_4$ are famous for highly stable material, which are expected to give contribution to make safer battery. In near future, the various materials having both capacity and safety will be developed by new technology, such as solid solution composite.

• Journal of Hydrogen and New Energy
• /
• v.25 no.5
• /
• pp.509-515
• /
• 2014

At the fuel processing system (FPS) of fuel cell vehicle, hydrogen recirculation blower (HRB) is used for the recirculation of remained hydrogen after reaction. In this paper, noise and vibration improvement of HRB is studied by changing design and control. It is checked the campbell diagram and critical speed for stability of rotor, and housing stiffness is improved using simulation of frequency response function (FRF). A method is suggested that can decrease the unbalance amount of the rotor and impeller which main source of noise and vibration. In order to reduce the noise during deceleration of blower, electrical braking is applied and tested the risk impact of durability. Founded the optimum switching frequency of the motor control, and reduced the idle rpm by increasing of aerodynamic performance. The superiority of paper is proved by measurement of the improved product's noise and vibration.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.5
• /
• pp.507-517
• /
• 2010

The KOREAN AIR - R&D Center has developed a solar array for STSAT-2 Flight Model, SaTReC-KAIST, using a fully localized technology and has verified the performance through a launch vibration test, orbit environment test and electrical performance test. The solar array will be launched at NARO Space Center by KSLV-I which is the first Korean launch vehicle, in May 2010. In this paper, a current-voltage curve that shows the power characteristics of solar arrays was derived by applying elements that affects the power performance of STSAT-2's solar arrays to the solar cell equivalent models. The result was compared to LAPSS test results, and accuracy of the solar cell equivalent model and the power performance simulation has been analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.7
• /
• pp.4469-4474
• /
• 2014

This paper proposes a novel analysis method on the driving performance of LIM (linear induction motor) by FEM (finite element method). First, a linear model was converted with a rotation model to perform the dynamic analysis for a long time. Through the FEM model, the slip parameter for the control algorithm could be induced effectively. The LIM for the traction system was performed at a constant V/f in the region of constant torque, and a constant V and variable f in the region of constant power. Several slip characteristic curves according to the voltage and frequency were calculated by FEM in advance. The driving performance was then induced by interpolating the slip characteristic curves according to the load of the vehicle.

• Journal of IKEEE
• /
• v.18 no.3
• /
• pp.376-382
• /
• 2014

In this paper, we propose a advanced attitude PID controller and sensor fusion method robust to the vibration of the quadcopter unmanned air vehicle using four BLDC motors. When the gyro sensor and acceleration sensor are fused, a complementary filter is designed to ignore the vibrations generated by the motors and to complement the drawbacks. As a result, we obtain accurate results than using each sensor. Also, it is possible to obtain a low delay results in robust to vibration than the low-pass filter or moving average filter, which is generally used for quadcopter. And we improved D controller, which have being used for attitude control of quadcopter, to quadcopter using gyro sensor. it was confirmed that the attitude is stabilized and error is reduced By using gyro sensor output instead of variation of estimated angle in D control.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.4
• /
• pp.2335-2342
• /
• 2014

If you want to use the unmanned quad rotor for emergency information provision and information about the traffic situation of real-time and moving information is included in the car to help in emergency vehicle operation of the city and in the distribution future innovation the need to consider to have enough safety of the use of silent quad rotor. Therefore, in this study, the unmanned quad rotor system research of safe landing control from the center for the improvement of safety of unmanned quad rotor system you have a motor of four, has taken a good structural balance system based on the dynamic model and motion considering the nonlinear characteristics, and attempts to proceed via non-linearity and system disturbances, tough Fuzzy controller, and analyzed through a computer simulation result.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.4
• /
• pp.97-108
• /
• 2016

In this paper, we consider a cooperative monitoring network, which consists of a large number of UAVs, in order to promptly detect event in a disaster area. A command center may not be able to control each UAV individually due to resource constraints. Therefore, UAVs need to autonomously construct a mobile monitoring network in order to maximize monitoring coverage and to adapt the network formation according to environment changes in the disaster area. To that end, we propose multiple UAVs-based cooperative monitoring schemes that uses virtual forces. In this monitoring scheme, an effective monitoring is enabled by extending monitoring coverage using each UAV's circle movements. The UAVs-based monitoring network can also be splitted or merged in order to increase the monitoring effectiveness. Through simulations, we show that the proposed scheme can effectively monitor a large area and achieve a high event detection ratio.