Jongsuk Ro

Prof. Dr. Jongsuk Ro

Electrical Energy Application Lab, Chung-Ang University, Seoul, Korea
orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

View All Publications
13 September 2021 in IEEE Access
Verified
Journal Article
Open access
MKMOHD KHALID
MOHD KHALID
Irfan KhanIrfan Khan
Irfan Khan
SHSalman Hameed
Salman Hameed
MAM. Syed Jamil Asghar
M. Syed Jamil Asghar
Jongsuk RoJongsuk Ro
Jongsuk Ro
The penetration of electric vehicles (EVs) in the transportation sector is increasing but conventional internal combustion engine (ICE) based vehicles dominates. To accelerate the adoption of EVs and to achieve sustainable transportation, the bottlenecks need to be elevated that mainly include the high cost EVs, range anxiety, lack of EV charging infrastructure, and the pollution of the grid due to EV chargers. The high cost of EVs is due to costly energy storage systems (ESS) with high energy density. This paper provides a comprehensive review of EV technology that mainly includes electric vehicle supply equipment (EVSE), ESS, and EV chargers. A detailed discussion is presented on the state-of-the-art of EV chargers that include on-/off-board chargers. Different topologies are discussed with low-/high-frequency transformers. The different available power levels for charging are discussed. To reduce the range anxiety the EV chargers based on inductive power transfer (IPT) are discussed. The last part of the paper focuses on the negative impact of EV chargers along with the remedies that can be adopted. The international standards decided by different institutions and adopted universally are discussed in the latter part of this paper and finally, this paper concludes with the near to future advancement in EV technology.

6 August 2021 in Mathematical Problems in Engineering
Verified
Journal Article
Open access
PDF file
TNTehreem Nasir
Tehreem Nasir
SBSyed Sabir Hussain Bukhari
Syed Sabir Hussain Bukhari
SRSafdar Raza
Safdar Raza
Hafiz Mudassir MunirHafiz Mudassir Munir
Hafiz Mudassir Munir
MAMuhammad Abrar
Muhammad Abrar
RMRooha Masroor
Rooha Masroor
The concept of smart grid was introduced a decade ago. Demand side management (DSM) is one of the crucial aspects of smart grid that provides users with the opportunity to optimize their load usage pattern to fill the gap between energy supply and demand and reduce the peak to average ratio (PAR), thus resulting in energy and economic efficiency ultimately. The application of DSM programs is lucrative for both utility and consumers. Utilities can implement DSM programs to improve the system power quality, power reliability, system efficiency, and energy efficiency, while consumers can experience energy savings, reduction in peak demand, and improvement of system load profile, and they can also maximize usage of renewable energy resources (RERs). In this paper, some of the strategies of DSM including peak shaving and load scheduling are highlighted. Furthermore, the implementation of numerous optimization techniques on DSM is reviewed.

1 May 2020 in Energies
Verified
Journal Article
Open access
PDF file
Irfan SamiIrfan Sami
Irfan Sami
Shafaat UllahShafaat Ullah
Shafaat Ullah
ZAZahoor Ali
Zahoor Ali
NUNasim Ullah
Nasim Ullah
Jongsuk RoJongsuk Ro
Jongsuk Ro
The doubly fed induction generator (DFIG)-based wind energy conversion systems (WECSs) are prone to certain uncertainties, nonlinearities, and external disturbances. The maximum power transfer from WECS to the utility grid system requires a high-performance control system in the presence of such nonlinearities and disturbances. This paper presents a nonlinear robust chattering free super twisting fractional order terminal sliding mode control (ST-FOTSMC) strategy for both the grid side and rotor side converters of 2 MW DFIG-WECS. The Lyapunov stability theory was used to ensure the stability of the proposed closed-loop control system. The performance of the proposed control paradigm is validated using extensive numerical simulations carried out in MATLAB/Simulink environment. A detailed comparative analysis of the proposed strategy is presented with the benchmark sliding mode control (SMC) and fractional order terminal sliding mode control (FOTSMC) strategies. The proposed control scheme was found to exhibit superior performance to both the stated strategies under normal mode of operation as well as under lumped parametric uncertainties.

6 October 2020 in IEEE Access
Verified
Journal Article
Open access
Irfan SamiIrfan Sami
Irfan Sami
Shafaat UllahShafaat Ullah
Shafaat Ullah
ABAbdul Basit
Abdul Basit
NUNasim Ullah
Nasim Ullah
Jongsuk RoJongsuk Ro
Jongsuk Ro
In the direct torque control (DTC) of induction motor (IM) drive systems utilizing model predictive torque control (MPTC) in the inner loop and classical proportional integral (PI) control in the outer loop is prone to weaknesses, such as uncertainties, external disturbances, parameter variations, and nonlinear dynamics. A high-performance control system for speed and torque is required to guarantee a smooth and robust control architecture that can withstand such unpredictable effects. In this study, we propose an integral super twisting sliding mode control (ISTSMC) to address the shortcomings of the classical PI used in the outer loop of DTC drive systems. A sliding mode speed observer is also designed and utilized to overcome problems associated with mechanical sensors. The robustness of the proposed control strategy and fast dynamic speed response are compared favorably with a benchmark PI controller and conventional sliding mode control (SMC). The ability of the proposed system to regulate both speed and torque was evaluated through simulations, under various fault perturbations, parameter variations, and load disturbances, conducted in MATLAB/ Simulink. Various performance indices were used to demonstrate the superior performance of the proposed strategy compared to a benchmark PI system and conventional SMC-based MPTC approaches.

24 September 2020 in IEEE Access
Verified
Journal Article
Open access
Irfan SamiIrfan Sami
Irfan Sami
NUNasim Ullah
Nasim Ullah
S.M. MuyeenS.M. Muyeen
S.M. Muyeen
KTKuaanan Techato
Kuaanan Techato
SCShahariar Chowdhury
Shahariar Chowdhury
Jongsuk RoJongsuk Ro
Jongsuk Ro
The penetration of renewable energy sources on a large scale in conventional electric networks increases exponentially for environmental preservation. However, the increase in RESs leads to some technical problems that include (a) fluctuations in power production, (b) less or no generation units for power balancing, (c) reduced inertia due to RESs decoupling from the conventional grid using converters. Micro-hydro power plants (MHPPs) are emerging as a mature balancing technology and a great alternative to large hydropower plants as they encounter population displacement and many environmental problems. Modern pump storage MHPPs uses a power converter between the grid and machine to control the consumption of power during pumping mode. This power electronic interface loses the ability of the rotating mass of the machine to contribute to the grid inertia by making it independent of the grid frequency. This problem is solved through the control of power converters in such a way that the inertia effect is synthesized termed as synthetic inertia. MHPPs can also be operated in a standalone mode where they are not connected to the grid. This paper reviews control schemes applied in literature for the frequency, voltage, and inertia control, in both the grid-connected and standalone modes. This study starts with the standalone MHPPs, covering the literature review and control structure for voltage and frequency control of standalone MHPPs. Then it presents a detailed operation, control principle, synthetic inertia concepts, and architecture of grid-connected MHPPs. The mathematical formulation of the grid, permanent magnet synchronous generator, synthetic inertia inclusion, and control structures, including direct torque control, virtual synchronous machine, and model predictive control, is also presented. Finally, the paper presents the concluding remarks with the comparative analysis of various control structures to include synthetic inertia, its suitability, and future scope for MHPPs.

13 February 2017 in IEEE Transactions on Magnetics
Verified
Journal Article
Closed access
HYHan-Kyeol Yeo
Han-Kyeol Yeo
HPHyeon-Jeong Park
Hyeon-Jeong Park
JSJung-Moo Seo
Jung-Moo Seo
SJSang-Yong Jung
Sang-Yong Jung
Jongsuk RoJongsuk Ro
Jongsuk Ro
HJHyun-Kyo Jung
Hyun-Kyo Jung
Recently, overhang structures are increasingly used for various applications requiring high torque and power densities in a limited space such as traction motors of electric vehicles and servo motors of robot arms. In the design stage, overhang effects should be taken into account to predict the performances and the temperature rise of a motor with overhang. However, little research has been conducted on the thermal characteristics and analysis methods for a surface-mounted permanent-magnet (SPM) motor with overhang. To address this problem, the electromagnetic and thermal characteristics of the SPM motors with and without overhang are invested in this paper. Specifically, 3D finite-element method is used in electromagnetic analysis to accurately calculate electromagnetic losses which are heat sources in thermal analysis. Moreover, the lumped-parameter thermal network (LPTN) which can consider overhang effects rapidly and precisely is proposed as an analytical method. Through the proposed LPTN, the computation time for thermal analysis is reduced considerably in comparison with a computational fluid dynamics method, and the temperature rise of the motors are precisely predicted. The results calculated in electromagnetic and thermal analysis are verified experimentally with 0.3 Nm, 20- pole/24-slot SPM motors adopting natural cooling.