KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 10 of 10

Some of the metrics are blocked by your
consent settings
Enhanced robust frequency stabilization of a microgrid against simultaneous cyber-attacks
(2024-03-01)
Kerdphol, Thongchart
;
Ngamroo, Issarachai
;
Surinkaew, Tossaporn
A microgrid (MG) is a smart grid cyber-physical system, with component coordination relying on cyber resilience. Weak communications, protocols, and tools make the MG's secondary frequency control vulnerable to various cyber-attacks, posing new challenges and stability risks. In response to this challenge, this paper introduces the enhanced robust H<inf>∞</inf> technique considering the dynamic impacts of cyber-attacks on secondary frequency control to develop a secondary frequency control loop, improving the regulation performance and cyber resiliency of the MG frequency. The secondary control cyber-attack strategies mainly rely on false data injection (FDI), denial of service (DoS), and controller hijacking. These attack techniques are simultaneously considered in formulating the H∞ problem and control synthesis as unstructured parametric uncertainty, attenuating the concurrent cyber impacts. The study extends a load frequency control model to illustrate how cyber-attacks can be represented mathematically and physically in the MG. The results reveal that cyber-attacks affect secondary frequency control elements differently depending on the type of cyber threats used. By implementing an enhanced H∞ controller, the MG can effectively maintain stable frequency levels even when faced with malicious attacks and disruptions caused by renewable energy sources and loads.
Some of the metrics are blocked by your
consent settings
Synthetic Inertia-Power Sharing in High Renewable Power Grids Through Vehicle-to-Grid Topology
(2024-01-01)
Kerdphol, Thongchart
;
Surinkaew, Tossaporn
;
Ngamroo, Issarachai
With the increasing integration of renewable energy sources (RESs), the overall inertia of the power system is expected to decline. The remaining inertia is crucial for regulating system frequency and mitigating excessive rates of change. The deployment of dispatchable loads, such as electric vehicles (EVs), offers a promising solution. This paper presents a synchronized inertia support framework utilizing a vehicle-to-grid (V2G) system through its bidirectional chargers. This concept is realized by integrating a large-scale energy storage system (ESS) composed of controllable EVs into an enhanced inertia emulation structure. The synthetic inertia control strategy has been refined to account for EV user convenience and synchronized state of charge (SOC) management, facilitating synchronized inertia power sharing. This approach enhances the grid's dynamic performance and resilience. Simulation results demonstrate that the proposed method effectively delivers rapid inertia support from the onboard ESS of EVs, improving frequency stability.
Some of the metrics are blocked by your
consent settings
Distributed frequency suppression method using inverter for photovoltaic power generation
(2019-07-01)
Kato, Koki
;
Iwane, Yuji
;
Horie, Shunsuke
;
Goda, Tadahiro
;
Yukita, Kazuto
In this paper, the frequency variation suppression method for dispersed photovoltaic power generation (PV) is proposed. The variation of system frequency can occur due to the shortage of power generator adjustment under the massive installation of PV. In addition, the PV which is not equipped with frequency control results in the system frequency change. To handle this problem, a frequency control method by giving generator constants to distributed PVs is presented. Since, the distributed PVs cannot exchange information such as power generation amount and solar radiation amount etc., only the capacity of distributed PV is used. As a result, the generator constants of each PV can be calculated, and the frequency control can be performed. Study results confirm that the power generation output of PV which changes momentarily can be supplemented by giving the generator constants to distributed PVs.
Some of the metrics are blocked by your
consent settings
Coordinated PHEV, PV, and ESS for Microgrid Frequency Regulation Using Centralized Model Predictive Control Considering Variation of PHEV Number
(2018-01-01)
Pahasa, J.
;
Ngamroo, I.
The integration of plug-in hybrid electric vehicles (PHEVs), photovoltaic (PV) generators, and energy storage systems (ESSs) into microgrids is highly anticipated. A coordinated control of PHEVs, PVs, and ESS will support frequency control in a microgrid. However, the size of the ESS depends on the surplus power of PV. The lower the surplus power is, the smaller the size of ESS. Furthermore, the number of available PHEVs vary with the cumulative number of the participating PHEVs. This variation of the number of PHEVs may reduce the PHEVs' control effect in the microgrid. This paper proposes a coordinated control of PHEVs, PVs, and ESSs for frequency control in the microgrid using a centralized model predictive control (CMPC) considering the variation of PHEV numbers. The objectives of the coordinated control are: 1) to suppress the system frequency fluctuation and 2) to minimize the surplus power of PV and, therefore, reduce the size of ESS. Simulation studies indicate that the coordinated control of PHEVs, PVs, and ESSs by the proposed CMPC is superior to that of the proportional integral derivative control and the distributed MPC in terms of minimizing the frequency fluctuation, the PV surplus power, and the ESS size.
Some of the metrics are blocked by your
consent settings
PSO-based specified structure mixed H2/H∞ multiple PHEV controllers for robust frequency control in interconnected power systems with large wind farms
(2013-01-16)
Rattanapornchai, Chalotorn
;
Ngamroo, Issarachai
This paper focuses on the new robust control design of multiple plug-in hybrid electric vehicle (PHEV) units for frequency control in interconnected power systems with large wind farms. The controller structure of PHEV is specified as a proportional integral (PI). Unstructured system uncertainties such as various wind patterns, system parameters variation, are modeled by the inverse output multiplicative perturbation. The particle swarm optimization is applied for tuning the PI parameters for all PHEV units based on the mixed H<inf>2</inf>/H<inf>∞</inf> control approach. Simulation results confirm the superior performance and robustness of the proposed PHEV controller. © 2013 ISSN 1881-803X.
Some of the metrics are blocked by your
consent settings
Bidirectional power controller design of PHEV for robust frequency control
(2012-06-12)
Ngamroo, Issarachai
;
Rattanapornchai, Chalotorn
This paper presents a bidirectional power controller design of plug-in hybrid electric vehicle (PHEV) for robust frequency control in the two-area interconnected power system with wind farms. The controller structure is a proportional integral (PI). System uncertainties such as various wind patterns, system parameters variation etc., are modeled by the inverse output multiplicative perturbation. The particle swarm optimization is applied for tuning the PI parameters based on the mixed H2/H∞ control technique. Simulation results confirm the superior performance and robustness of the proposed controller.
Some of the metrics are blocked by your
consent settings
Design of optimal fuzzy logic-PID controller using bee colony optimization for frequency control in an isolated wind-diesel system
(2009-12-16)
Chaiyatham, T.
;
Ngamroo, I.
;
Pothiya, S.
;
Vachirasricirikul, S.
Generally, the inevitable problems in the fuzzy logic-PID (FLPID) control design are the trial and error of the setting of scale factors, membership functions and control rules. To solve these problems, this paper proposes the optimal FLPID controller design using bee colony optimization (BCO) for the load frequency control in the microglia system. The considered microgrid is the hybrid wind-diesel isolated system. The BCO is applied to automatically optimize the FLPID controllers of governor in the diesel side and blade pitch control in the wind side. Simulation studies show the superior robustness of the optimal FLPID against system parameters variation in comparison with the optimal PID controller and the non-optimal FLPID controller.
Some of the metrics are blocked by your
consent settings
Robust frequency control of wind-diesel hybrid power system using superconducting magnetic energy storage
(2009-04-23)
Ngamroo, Issarachai
In an isolated wind-diesel hybrid power system, the variable power consumptions as well as the intermittent wind power may cause a large fluctuation of system frequency. If the system frequency can not be controlled and kept in the acceptable range, the system may lose stability. To reduce system frequency fluctuation, a superconducting magnetic energy storage (SMES) which is able to supply and absorb active power quickly, can be applied. In addition, variation of system parameters, unpredictable power demands and fluctuating wind power etc., cause various uncertainties in the system. A SMES controller which is designed without considering such uncertainties may lose control effect. To enhance the robustness of SMES controller, this paper focuses on a new robust control design of SMES for frequency control in a wind-diesel system. The coprime factorization is used to represent the unstructured uncertainties in a system modeling. The structure of a SMES controller is the practical first-order lead-lag compensator. To tune the controller parameters, the optimization problem is formulated based on loop shaping technique. The genetic algorithm is applied to solve the problem and achieve the control parameters. Simulation results confirm the high robustness of the proposed SMES controller with small power capacity against various disturbances and system uncertainties in comparison with SMES in the previous research. © 2009 The Berkeley Electronic Press. All rights reserved.
Some of the metrics are blocked by your
consent settings
Robust pitch controller design in hybrid wind-diesel power generation system
(2008-09-23)
Cuk Supriyadi, A. N.
;
Ngamroo, I.
;
Kaitwanidvilai, S.
;
Kunakorn, A.
;
Hashiguchi, T.
In this paper, the robust control design of pitch controller for frequency control in a hybrid wind-diesel power generation system is proposed. The structure of the pitch controller is a 1<sup>st</sup>-order lead-lag compensator. To take system uncertainties into account, the coprime factorization is applied in system modeling. To obtain the controller parameters, the performance and stability conditions of H<inf>∞</inf> loop shaping technique are used to formulate the optimization problem. The genetic algorithm is employed to solve the problem. Simulation studies show the frequency control effect and robustness of the proposed controller against system uncertainties in comparison with a variable structure pitch control. ©2008 IEEE.
Some of the metrics are blocked by your
consent settings
Switching frequency control based on phase-locked loop for a current-fed parallel resonant inverter
(2007-10-01)
Ponwiangkum, N.
;
Kittiratsatcha, S.
This paper proposes a computer simulation in PSCAD program of a current-fed parallel resonant inverter. Even though the circuit parameters such as permeability and conductivity have changed regarding to the changing temperature during the heating period. The proposed idea is able to control the phase difference Δθ between the output voltage and output current to be constant at desired value. The principle of the proposed controller utilizes the phaselocked loop with a phase frequency detector. If the Δθ is constant without any effect from the temperature change, then the output power will be controlled precisely by adjusting only the dc-link current. The proposed idea is verified by the experimental results. © 2007 IEEE.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results