• 자동차안전학회지
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• 제10권2호
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• pp.36-42
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• 2018

UNECE/WP29/GRPE/EVE has recently defined that the power of a hybrid electric vehicle is the system power. Although a method for measuring the maximum power of a hybrid electric vehicle is presented by KATRI, it does not consider charging and discharging characteristics of traction batteries. This study provides a maximum power measurement method which reflects the charging and discharging characteristics of traction batteries in NOVC-HEVs (Not Off Vehicle Charging-Hybrid Electric Vehicles). Both methods are compared with regard to the output measurement results.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1016-1026
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• 2017

An adaptive extended Kalman filter based on the maximum likelihood (EKF-ML) is proposed for detecting voltage sag in this paper. Considering that the choice of the process and measurement error covariance matrices affects seriously the performance of the extended Kalman filter (EKF), the EKF-ML method uses the maximum likelihood method to adaptively optimize the error covariance matrices and the initial conditions. This can ensure that the EKF has better accuracy and faster convergence for estimating the voltage amplitude (states). Moreover, without more complexity, the EKF-ML algorithm is almost as simple as the conventional EKF, but it has better anti-disturbance performance and more accuracy in detection of the voltage sag. More importantly, the EKF-ML algorithm is capable of accurately estimating the noise parameters and is robust against various noise levels. Simulation results show that the proposed method performs with a fast dynamic and tracking response, when voltage signals contain harmonics or a pulse and are jointly embedded in an unknown measurement noise.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1447-1453
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• 2014

This paper proposes the new method based on the availability of three points measurement and convexity of photovoltaic (PV) curve characteristic at the maximum power point (MPP). In general, the MPP tracking (MPPT) function is the important part of all PV systems due to their power-voltage (P-V) characteristics related with weather conditions. Then, the analog-to-digital converter (ADC) and low pass filter (LPF) are required to measure the voltage and current for MPPT by the digital controller, which is used to implement the PV power conditioning system (PCS). The measurement and quantization error due to rounding or truncation in ADC and the delay of LPF might degrade the reliability of MPPT. To overcome this limitation, the proposed method is proposed while improving the performances in both steady-state and dynamic responses based on the detailed investigation of its properties for availability and convexity. The performances of proposed method are evaluated with the several case studies by the PSCAD/EMTDC$^{(R)}$ simulation. Then, the experimental results are given to verify its feasibility in real-time.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.781-789
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• 2022

KHNP had licensed Dynamic Control rod Reactivity Measurement (DCRM) method using detector current signals of PWRs in 2006. The method has been applied to all PWRs in Korea for about 15 years successfully. However, the original method was inapplicable to PWRs using low-sensitivity integral fission chamber as ex-core detectors because of their pulse pile-up and the nonlinearity of the mean-square voltage at low power region. Therefore, to overcome this disadvantage, a modified method, DCRM-EK, was developed using kinetics behavior after equilibrium condition where the pulse counts maintain the maximum value before pulse pile-up. Overall measurement, analysis procedure, and related computer codes were changed slightly to reflect the site test condition. The new method was applied to a total of 15 control rods of 1000 MWe and 1400 MWe PWRs in Korea with worths in the range of 200 pcm -1200 pcm. The results show the average difference of -0.4% and the maximum difference of 7.1% compared to the design values. Therefore, the new DCRM-EK will be applied to PWRs using low sensitivity integral fission chambers, and also can replace the original DCRM when the evaluation fails by big noises present in current or voltage signals of uncompensated/compensated ion chambers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.151-153
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• 2007

In this paper, the control method of extracting maximum power from the seaflow energy is proposed. This system consists of buck-boost converter, bridge diode. The control is performed by using the variable duty ratio control of buck-boost converter. For extracting maximum power, it is necessary to know the seaflow turbine's maximum power curve and the seaflow speed measurement. But this makes the system difficult and expensive to implement. So this paper proposes the MPPT control method where the seaflow speed and the maximum power curve of the seaflow turbine are not required. The effectiveness of algorithm is simulated based on Matlab $Simulink^{(R)}$.

• 자동차안전학회지
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• 제8권3호
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• pp.22-27
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• 2016

As a preliminary research to provide amendment for the engine performance test regulation of two-wheeled vehicles, the engine performance data are investigated in terms of maximum torque, rated power, and engine speed of motorcycles on sales in Korean market. Based on the engine performance database officially published to consumers, some forecasted problems are discussed when the maximum torque and the rated power are measured under the present test standards. EU and Korea regulations on engine performance test are carefully compared in terms of the accuracy of measurement devices, test procedures including data acquisition method, and allowable range of rated power measurement. Complementary items are discussed to eliminate ambiguities in the present regulation and to construct rational regulation system.

• 한국자동차공학회논문집
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• 제22권7호
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• pp.135-143
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• 2014

Electrified vehicles can be classified with hybrid electric vehicles, battery electric vehicles and fuel cell electric vehicles. These vehicles have two more than energy converters which are the part of a powertrain. It is particularly difficult to estimate the power of hybrid electric vehicles due to two different energy converters with different power characteristics. Therefore, a new power concept for these vehicles is needed. The vehicle power as the new concept for solving this problem was defined in this study. The test method and the procedure were made a development in this study. Four electrified vehicles with different electric fraction were used to validate the method. Two percentage of COV was suggested as a criterion for the maximum vehicles power based on the previous studies. The repeatability of this method was within ${\pm}2$ per cent for the maximum vehicle power and within ${\pm}5$ per cent for the vehicle speed at maximum vehicle power.

• 제어로봇시스템학회논문지
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• 제19권2호
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• pp.81-86
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• 2013

In this paper, the parameter identification for localization scheme for the optics-based micro sensor node is conducted. We analyzed short measurement range problem which can be occurred in optical based micro sensor node localization method using a time of flight. And we set up the theory for distance and maximum reflected laser power to overcome the problem by identifying hardware parameters like laser power, effective area of MEMS CCR, sensitivity of photodetector, and so on. Experimental results of measurement of maximum reflected laser power were compared with results of the theory. By using the theory, we can identify hardware parameters of localization scheme to measure particular position of the optics-based micro sensor node.

• 대한임베디드공학회논문지
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• 제18권1호
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• pp.9-17
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• 2023

This paper relates to the development of a device for measuring the efficiency of a solar panel based on a variable constant current, and proposed a standard for reuse of the solar panel. By applying a variable constant current circuit to a solar panel efficiency measuring device, it was easy to apply a maximum power point tracking (MPPT) algorithm. In addition, a load dispersion method was applied to measure the efficiency of a high-capacity solar panel. and it is possible to solve a problematic thermal runaway during a MOSFET parallel operation by applying the load dispersion method. As a result of the experiment, the solar panel efficiency measuring device was able to accommodate a large solar panel of 350W, which is the maximum measurement goal. In this paper, the validity was confirmed through the 310W solar panel efficiency measurement experiment collected after removal.

• 전력전자학회논문지
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• 제18권4호
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• pp.376-386
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• 2013

This paper proposes an improved Maximum Power Point Tracking method and design methods of unmanned solar vehicle system by parts of hardware, unmanned driving control and power conversion. The hardware design is offered on the weight reduction and structural reliability by using structural analysis software. The technique of curve fitting is applied to unmanned control system due to minimizing the vehicle's behavior. Furthermore, lateral controller applying actuator dynamics is robust enough to prevent performance degradation by measurement noise regarding position and heading angle. The power conversion system contains battery charger system and tapped-inductor boost converter. In the battery charger system, variable step-size MPPT is conducted for quick response of maximum power point tracking. The validity of the proposed algorithm are verified by simulations and experiments.