• Journal of Electrical Engineering and Technology
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• v.5 no.3
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• pp.415-422
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• 2010

The distributed flexible alternative current transmission system (D-FACTS) is a recently developed FACTS technology. Distributed Static Series Compensator (DSSC) is one example of DFACTS devices. DSSC functions in the same way as a Static Synchronous Series Compensator (SSSC), but is smaller in size, lower in price, and possesses more capabilities. Likewise, DSSC lies in transmission lines in a distributed manner. In this work, we designed a fuzzy logic controller to use the DSSC for enhancing transient stability in a two-machine, two-area power system. The parameters of the fuzzy logic controller are varied widely by a suitable choice of membership function and parameters in the rule base. Simulation results demonstrate the effectiveness of the fuzzy controller for transient stability enhancement by DSSC.

• Journal of the Korean Society of Safety
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• v.14 no.1
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• pp.55-65
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• 1999

Fuzzy logic fuzzy set theory is recently getting increasing emphasis in process control applications. This paper describes application of fuzzy logic in a speed control system that uses a phase controlled bridge converter and a separately excited dc motor. The fuzzy control is used to linearize the transfer characteristics of the converter in discontinuous conduction mod occurring at light load and high speed. The fuzzy control is then extended to the current and speed control loops replacing the conventional PI control method. The control algorithms have been developed in detail and verified by simulation of a DC motor(DM) drive system. The simulation result indicates the superiority of fuzzy control over the conventional control methods. Fuzzy logic seems to have a lot of promise in the applications of power electronics.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1235-1244
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• 2017

This paper proposes a fuzzy logic controlled new topology of high voltage gain zero voltage switching (ZVS) asymmetrical PWM full-bridge DC-DC boost converter for constant load and high power applications. The APWM full-bridge stage provides high voltage gain and soft-switching characteristics increase the efficiency and reduce the switching losses. Fuzzy logic controller (FLC) improves the performance and dynamic characteristics of the proposed converter. A comparison with a classical proportional-integral (PI) controller demonstrates the high performances of the proposed technique in terms of effective output voltage regulation under different operating conditions. Simulation is done by integrating two different simulation platforms $PSIM^{(R)}$ and $Matlab^{(R)}/Simulink^{(R)}$ by using SimCoupler tool of $PSIM^{(R)}$. Experimental results using 120W load have been provided to validate the results.

• Journal of the military operations research society of Korea
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• v.35 no.1
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• pp.1-19
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• 2009

This study aims to improve methodology for a Defense Simulation which is to calculate wartime stockpile requirement of artillery munitions for K-9 against armored vehicles. Due to incorrect data input and distortion in simulation logic, the expected occupancy ratio for each weapon system obtained from applying a traditional method using an analytical Defense Simulation shows considerable discrepancies from what we expect from a war in the future. This study analyzes causes for incorrect data input and phenomena of distortion in simulation logic. By taking measures to control these phenomena, the study aims to present trustworthy methodology for a Hybrid Defense Simulation which is to calculate wartime stockpile requirement of munitions for ground forces by interaction between a controlled training Defense Simulation model and a analytical Defense Simulation model

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.364-369
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• 1988

In this study, a model for the simulation of the material flow not only inside a robot cell with flexible handling sequence but also between robot cells is presented. A method for the connection of special simulation programs has been developed and a logic model between a real system and a simulation system is employed.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.1
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• pp.1-10
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• 2010

This paper proposes a two-phase clocked adiabatic static CMOS logic (2PASCL) circuit that utilizes the principles of adiabatic switching and energy recovery. The low-power 2PASCL circuit uses two complementary split-level sinusoidal power supply clocks whose height is equal to $V_{dd}$. It can be directly derived from static CMOS circuits. By removing the diode from the charging path, higher output amplitude is achieved and the power consumption of the diode is eliminated. 2PASCL has switching activity that is lower than dynamic logic. We also design and simulate NOT, NAND, NOR, and XOR logic gates on the basis of the 2PASCL topology. From the simulation results, we find that 2PASCL 4-inverter chain logic can save up to 79% of dissipated energy as compared to that with a static CMOS logic at transition frequencies of 1 to 100 MHz. The results indicate that 2PASCL technology can be advantageously applied to low power digital devices operated at low frequencies, such as radio-frequency identifications (RFIDs), smart cards, and sensors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1139-1143
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• 2003

HILS(Hardware-In-the-Loop Simulation) is a scheme that incorporates hardware components of primary concern in the numerical simulation environment. Due to its advantages over actual vehicle test and pure simulation, HILS is being widely accepted in automotive industries as test benches for vehicle control units. Developed in this study is a HILS system for EHB(Electro-Hydraulic Brake) systems that include a high pressure generator and a valve control system that independently modulates the brake pressures at four wheels. An EHB control logic was tested in the HILS system. Test results under various driving conditions are presented and compared with the VDC logic.

• Journal of the Korea Society for Simulation
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• v.14 no.4
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• pp.95-106
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• 2005

Recent advances in wireless sensor networks have led to many routing protocols designed for energy-efficiency in wireless sensor networks. Despite that many routing protocols have been proposed in wireless sensor networks, a single routing protocol cannot be energy-efficient if the environment of the sensor network varies. This paper presents a fuzzy logic based Adaptive Routing (FAR) algorithm that provides energy-efficiency by dynamically changing protocols installed at the sensor nodes. The algorithm changes protocols based on the output of the fuzzy logic which is the fitness level of the protocols for the environment. A simulation is performed to show the usefulness of the proposed algorithm.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.6
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• pp.584-590
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• 2000

Urban traffic situations are extremely complex and highly interactive. The multi-agent systems approach can provide a new desirable solution. Currently, a traffic simulator is needed to understand and explore the difficulties in an agent-oriented traffic control. This paper presents an agent-oriented fuzzy logic controller for multiple crossroads simulation. A fuzzy logic control simulation with variables of arrival, queue, and traffic volume could alleviate traffic congestion. We developed an agent-oriented simulator suitable for traffic junctions with η$\times$η intersections in Visual C++. The proposed method adaptively controls the cycle of traffic signals even though the traffic volume varies. The effectiveness of this method was shown through simulation of multiple intersections.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.389-394
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• 2004

A Fuzzy Logic Sliding Mode Control or FLSMC for the uninterruptible power system (UPS) is presented, which is tracking a sinusoidal ac voltage with specified frequency and amplitude. The FLSMC algorithm combines feedforward strategy with the Variable Structure Control (VSC) or Sliding Mode Control (SMC) and fuzzy logic control. The control function is derived to guarantee the existence of a sliding mode. FLSMC has an advantage that the stability of FLSMC can be proved easily in terms of VSC. Furthermore, the rules of the proposed FLSMC are independent of the number of system state variables because the input of the suggested controller is fuzzy quantity sliding surface value. Hence the rules of the proposed FLSMC can be reduced. The simulation results illustrate that the purposed approach gives a significant improvement on the tracking performances. It has the small overshoot in the transient and the smaller chattering in the steady state than the conventional VSC. Moreover, its can achieve the requirements of robustness and can supply a high-quality voltage power source in the presence of plant parameter variations, external load disturbances and nonlinear dynamic interactions.