Jae-Hak Choi

Jae-Hak Choi


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 August 2021 in Energies
Verified
Journal Article
Open access
PDF file
YKyerin kim
yerin kim
JKJae-Myeong Kim
Jae-Myeong Kim
Jae-Jung JungJae-Jung Jung
Jae-Jung Jung
SKSo-Yeon Kim
So-Yeon Kim
JCJae-Hak Choi
Jae-Hak Choi
HLHyun-Goo Lee
Hyun-Goo Lee
With the strengthening of international environmental regulations, many studies on the integrated electric propulsion systems applicable to eco-friendly ship are being conducted. However, few studies have been performed to establish a guide line for the overall pure electric propulsion ship design. Therefore, this paper introduces the comprehensive design of DC shipboard power system for pure electric propulsion ship based on battery energy storage system (BESS). To design and configure the pure electric propulsion ship, 2 MW propulsion car ferry was assumed and adopted to be the target vessel in this paper. In order to design the overall system, a series of design processes, such as the decision of the ship operation profile, BESS capacity selection, configuration of the power conversion systems for propulsion, battery charging/discharging procedures, classification of system operation modes, and analysis of the efficiency, were considered. The proposed efficient design and analysis of the pure electric propulsion ship was qualitatively and quantitatively validated by MATLAB Simulink tool. The methodology presented in this paper can help design real ships before the system commissioning.

22 March 2023 in Electronics
Verified
Journal Article
Open access
PDF file
KTKhanh Vu Tran
Khanh Vu Tran
Sarbajit PaulSarbajit Paul
Sarbajit Paul
JLJaewoon Lee
Jaewoon Lee
JCJae-Hak Choi
Jae-Hak Choi
PHPil-Wan Han
Pil-Wan Han
Yon-Do ChunYon-Do Chun
Yon-Do Chun
The Korean government is facing growing concern over the increasing levels of fine dust. A significant contribution to this problem comes from coastal vessels. To mitigate this, an electric ship propulsion system has been proposed as a solution to reduce air pollution. The application of a fully electric propulsion system in a ship is challenging due to size, capacity limitations, and the cost investment of the battery system. To address the challenges of battery limitation and initial investment costs, the development and supply of removable battery supply systems (RBSSs) for fully electrified battery powered (F-EBP) car ferries are studied. A permanent magnet synchronous motor (PMSM) for the F-EBP car ferry using a roll-on/roll-off-type RBSS is developed in this work. Firstly, the concept of the F-EBP car ferry is discussed, and the specifications of the electric car ferry propulsion system are provided. Secondly, motor design and electromagnetic analysis are performed using finite-element analysis (FEA), where the heat sources including copper loss, core loss, and PM loss are calculated. Mechanical loss is also considered. Finally, a thermal network of the motor is built considering the lumped-parameter model. The results of the thermal analysis indicate that the motor operates within the safe region and can perform well in rated working conditions.

1 February 2012 in International Journal of Applied Electromagnetics and Mechanics
Verified
Journal Article
Closed access
PDF file
JCJae-Hak Choi
Jae-Hak Choi
DKDong-Jun Kim
Dong-Jun Kim
YCYon-Do Chun
Yon-Do Chun
PHPil-Wan Han
Pil-Wan Han
DKDae-Hyun Koo
Dae-Hyun Koo
JLJu Lee
Ju Lee
The approximate optimization based on a response surface modeling has been applied to the optimum design for obtaining flat torque of switched reluctance motor, which has high fluctuating torque due to its inherent salient structure. In order to reduce the fluctuating torque ripple causing noise and vibration, an optimization design technique has been introduced and investigated to find geometric and electric variables by means of combining finite element analysis considering driving circuits and response surface modeling. In this research an effective optimization method based on a response surface modeling has been used to overcome the modeling noise in formulating an objective and constraint and the cumulative numerical inaccuracy.

27 February 2024 in IEEE Transactions on Applied Superconductivity
Verified
Journal Article
Closed access
HKHyung-Wook Kim
Hyung-Wook Kim
YCYoon Seok Chae
Yoon Seok Chae
JKJi Hyung Kim
Ji Hyung Kim
HKHo Min Kim
Ho Min Kim
SKSeog-Whan Kim
Seog-Whan Kim
YJYoung-Sik Jo
Young-Sik Jo
This paper presents the results of a study conducted to experimentally investigate the effectiveness of implementing smart insulation (SI) coils in high-temperature superconducting rotating machines (HTSRMs). The obtained results mainly focus on the design and parameter extraction for the proposed method. Utilizing the stator of an existing 1-MW-class superconducting motor, the electromagnetic design of the new rotor was conducted for an approximate power rating of 100 kW. In addition, a static analysis was performed to extract the parameters required to conduct load testing on an HTSRM. Additionally, the SI field coil was manufactured to conduct critical current measurements; the obtained values were compared and analyzed with respect to the wire characteristics.

1 February 2010 in International Journal of Applied Electromagnetics and Mechanics
Verified
Journal Article
Closed access
PDF file
JCJae-Hak Choi
Jae-Hak Choi
YCYon-Do Chun
Yon-Do Chun
PHPil-Wan Han
Pil-Wan Han
DKDae-Hyun Koo
Dae-Hyun Koo
JIJong-Bin Im
Jong-Bin Im
JLJu Lee
Ju Lee
This paper deals with the design of the structure and shape of writing probes in alternative electric data storage devices based on electric polarization fields. In order to design high recording density electric recording devices, the shape of the writing probe is optimized using a response surface methodology. The structure of a writing probe is also investigated according to the existence and nonexistence of the electric shield. The static and dynamic characteristic of recording density is analyzed and compared with conventional recording devices based on the magnetic magnetization field.