A5047037844- Microgrid Control and Optimization
- Islanding Detection in Power Systems
- Frequency Control in Power Systems
- Power Systems and Renewable Energy
- HVDC Systems and Fault Protection
- Smart Grid Energy Management
- Real-time simulation and control systems
- Railway Systems and Energy Efficiency
- Advanced DC-DC Converters
- Advanced Battery Technologies Research
- Multilevel Inverters and Converters
- Power Systems and Technologies
- Hybrid Renewable Energy Systems
- Electric and Hybrid Vehicle Technologies
- High-Voltage Power Transmission Systems
- Wind Turbine Control Systems
- Low-power high-performance VLSI design
- Smart Grid and Power Systems
- Optimal Power Flow Distribution
- VLSI and FPGA Design Techniques
- Electric Power Systems and Control
- Railway Engineering and Dynamics
- Power Systems Fault Detection
- Power Line Communications and Noise
- Smart Grid Security and Resilience
Korea Electrotechnology Research Institute
2022-2024
Korea Economic Research Institute
2020
Incheon National University
2012-2019
The controller of the interlinking converter (ILC) in a hybrid ac/dc microgrid (MG) system plays an important role maintaining power sharing between ac and dc MG systems. coordination control ILC controllers secondary each should be considered to maintain proper among two MGs improve qualities system. This paper proposes distributed strategy for MG. proposed not only regulates accurate current reactive DGs MGs, but also maintains restores frequency voltage their nominal values. hierarchical...
The integration of smart grid technologies in interconnected power system networks presents multiple challenges for the industry and scientific community. To address these challenges, researchers are creating new methods validation of: control, interoperability, reliability Internet Things systems, distributed energy resources, modern equipment applications covering stability, operation, cybersecurity. Novel laboratory testing electrical systems incorporate novel simulation techniques...
Multiple microgrid (MG) systems can exist in a wide geographical area. They interconnect and operate on different frequency qualities to enhance the penetration of renewable energy resources. To multiple MGs qualities, framework stand-alone multimicrogrid (MMG) system is proposed this study. In MMG system, each MG connects common dc line through an ac/dc interlinking converter. A droop control for converter improve performance achieve autonomous power sharing. The sensitivity analysis with...
A stand-alone multi-microgrid (MMG) system can be formed by connecting multiple microgrids (MGs). In the MMG where frequencies of each MG are different, a back-to-back (BTB) converter used for interconnecting adjacent system. The frequency control performance improved designing suitable controller BTB converter. This study proposes multi-frequency in to improve regulation Autonomous power sharing between is achieved using proposed control. two systems with different nominal interconnected...
Battery energy storage systems (BESSs) have been widely used for microgrid control. Generally, BESS control are based on proportional-integral (PI) techniques with the outer and inner loops PI regulators. Recently, model predictive (MPC) has attracted attention application to future processing because it can easily deal multivariable cases, system constraints, nonlinearities. This study considers of MPC-based BESSs Two types MPC presented in this study: power (PPC) current (PCC) loops. In...
Microgrids are eco-friendly power systems because they use renewable sources such as solar and wind the main source. However, stochastic nature of is a considerable challenge for efficient operation microgrids. Microgrid operations have to satisfy quality requirements in terms frequency voltage. To overcome these problems, energy storage short- long-term used with Recently, short-term flywheels has attracted significant interest potential solution this problem. Conventional flywheel exhibit...
This paper presents a model predictive control for the superconducting magnetic energy storage (MPC-based SMES) system, which can be applied to voltage source converter and dc/dc chopper in SMES system together. The is implemented microgrid constant power flow at point of common coupling, frequency, microgrid. performance MPC-based compared with that proportional-integral (PI) method. harmonics involved dc current coil are analyzed estimate reduction eddy losses PI technique. efficacy...
Model predictive control (MPC) has been widely studied for regulating frequency in stand-alone microgrids (MGs), owing to the advantages of MPC such as fast response and robustness against parameter uncertainties. Understanding impacts system parameters on performance could be useful designing process controller achieve better performance. This study analyzes impact regulation a MG. The typical MG, which consists diesel engine generator, an energy storage (ESS), wind turbine load, is...
In a hybrid ac-dc microgrid, stiff voltage sources may appear in either the dc or ac subgrids, which gives rise to multiple operation modes as power dispatch changes. This creates challenge for designing interlink converter between and since different require controls. To solve this problem, paper proposes concept of transfverter inspired by how transformers link grids. Like transformer, can react presence on side reflect "stiffness" stabilizing capability other side. A back-to-back with...
Multiple power converters based on the droop controllers have been used widely in microgrid (MG) system. However, owing to different response time among several types of such as grid-feeding and grid-forming converters, low frequency oscillation occurs with high overshoot transient state. This paper proposes a novel control strategy virtual synchronous generator (VSG) for improving parallel during large disturbance stand-alone microgrid. The proposed VSG control, which inherits state...
Since the penetration of distributed energy resources (DERs) and storage systems (ESSs) into microgrid (MG) system has increased significantly, sudden disconnection DERs ESSs might affect stability reliability whole MG system. The low-voltage ride-through (LVRT) capability to maintain stable operation should be considered. main contribution this study is propose a control, based on dynamic consensus algorithm for LVRT proposed control method hierarchical that consists primary secondary...
The energy management systems used in microgrid are either centralized or decentralized. method is easy to implement, but has low reliability and it computationally intensive due its reliance on a single control unit. decentralized more reliable strategy as multiple units coordinated manage the system, however, algorithm implementation complicated for long-term operation. This paper proposes consensus-based hybrid multi-agent system including both agents taking advantages of methods into...
Direct current (DC) connection of the large-scale wind generations with high voltage levels and long distance has been widely developed. Meanwhile, medium direct (MVDC) can also offer similar benefits compared to generations. This study presents a comparison MVDC MVAC for integration distributed The system is adopted from IEEE 15-bus radial distribution system. generators based on doubly fed induction (DFIG) those control schemes grid are described. Several test cases such as loss generator,...
Variable switching frequency in the finite control set model predictive (FCS-MPC) method causes a negative impact on converter efficiency and design of output filters. Several studies have addressed problem, but they are either complicated or require heavy computation. This study proposes new (MPC) with constant frequency, which is simple to implement needs only small computation time. The proposed MPC based gradient descent (GD) find optimal voltage vector. Since cost function represented...
During islanded mode operation, the rated frequency of a microgrid should be maintained. For this, battery energy storage systems (BESS) can used. In this paper, coordinated control Lead-acid BESS and Lithium-ion (Li-ion) during operation is dealt with. Through simulation, proposed scheme based on characteristics Li-ion tested to show validation.
Several control strategies of the finite set model predictive controls (FCS-MPC) have been proposed for power converters, such as current (PCC), direct (DPPC), and voltage (PVC). However, microgrid (MG) applications, strategy FCS-MPC a converter might be changed according to operation mode MG system, which results in transient response system or during transition. This study proposes new use both islanded grid-connected modes an system. Considering characteristic synchronous generator, phase...
Multiple battery energy storage systems (BESSs) are used to compensate for the fluctuation in wind generations effectively. The stage of charge (SOC) BESSs might be unbalanced due difference speed, initial SOCs, line impedances and capabilities BESSs, which have a negative impact on operation farm. This paper proposes distributed control conversion system (WECS) based dynamic average consensus algorithm balance SOC There three controllers WECS with integrated BESS, including machine-side...
The efficiency of the microgrid (MG) system is depended on converter and power line losses. loss relies load condition whereas affected by impedance. Improving MG should consider both types This paper proposed a distributed coordination control strategy generation (DGs) in for improvement considering losses line. A cost function defined. diffusion algorithm used secondary each DG to optimize function. finds output that provides highest efficiency. Considering minimization losses, could be...
The scott transformer is used to supply single-phase power the AC railway system. Since a passive facility, it cannot regulate load-side voltage according load change. Meanwhile, Voltage Source Converter (VSC) able convert and control active reactive power. In this paper, feasibility of system based on Back-to-Back (BTB) VSC which composed rectifier, DC-DC converter, inverter, has been proposed. A three-phase BTB modeled. proposed tested Matlab/Simulink.
A microgrid is a small scale power system. The operated in two operation modes, the grid-connected mode and islanded mode. In mode, frequency of should be maintained constantly. For this, balance between supply demand during met. general, energy storage systems (ESSs) are used to solve imbalance. this paper, control effect Lithium-ion battery system (Li-ion BESS) has been tested on hardware-in-the loop simulation (HILS) environment.
Hybrid microgrid consists of AC and DC grids, in which the interlinking converter is used to connect microgrids.The droop control scheme widely applied hybrid including because it can be power without communication.However, existing steadystate error conventional might affect quality sensitive load.Therefore, improved proposed this study, steady-stated removed by using an additional PI regulator.Various simulation scenarios term load variations are performed MATLAB/Simulink environment...
Roles of energy storage systems (ESSs) in microgrid control are very important because a has uncontrollable sources such as the wind turbine and power trade with utility grid. Especially, ESSs have different characteristics – density density. The show trade-off. For this reason, coordinated among considering their is required. In paper, SMES BESS tested high reliability using hardware-in-the-loop simulation (HILS) system two grid-connected islanded modes.
With the increasing penetration level of renewable energy sources, rotational inertia in power systems is gradually decreasing by replacing conventional synchronous generators (SGs) with inverter-based resources. The loss deteriorates system dynamics such as large frequency excursion after disturbance. To enhance stability, grid-forming (GFM) inverters have gained attention owing to their capability forming AC grid without connecting an extra voltage source. However, a high GFM may cause...
The circulating current among the parallel inverter-based distributed generations (DGs) in microgrid (MG) system causes several negative impacts on operation of inverters. suppression should be considered controller design inverter, especially case using finite control set model predictive (FCS-MPC) which switching frequency inverter is varied. This paper proposed an MPC with constant for MG system. based use virtual state vectors addition to real inverter. discrete time used find optimal...