• The KSFM Journal of Fluid Machinery
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• v.12 no.3
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• pp.38-43
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• 2009

The Shiwhaho is an artificial lake located in Yellow sea of Korea where the ocean tidal current is significantly strong, and the tidal power plant is currently being under construction to generate electric power from the ocean tidal current. In addition to the tidal power plant under construction, an ocean current power park was proposed to maximize the power generation by utilizing the ocean current generated by the tidal power plant. To evaluate the feasibility of such combined power plant, the flow characteristics in the ocean current power parks connected with the tidal power plants were investigated numerically in the present study. When two different type of generations are operating together as a system, their interference may occur, which affects their efficiency. Therefore, the minimum distances between the tidal power plants and the ocean current power generators are studied in the present study to minimize such interference. The feasible region to generate power around the Shiwha tide embankment is also predicted by considering predicted ocean current speed distribution. Various arrangements of the ocean current generators are examined and an optimal arrangement is also discussed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.2
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• pp.45-53
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• 2013

In this paper, we analyze the typical phase voltage and line current waveform characteristics of the distribution system with 3 phase small synchronous generation source in case with load and non-load group, in order to investigate the power quality for end load connected of generation source. As demonstrated by our experimental results, the distortion and power quality of phase voltage and line current waveform were relatively good for low voltage 3 phase model grids connected of 3 phase small synchronous generation source in case with non-load group. However, distortion and power quality of voltage and current waveform was poor for low voltage 3 phase model grids connected to 3 phase small synchronous generation source in the load group with some phase voltage and frequency difference. From the above results, we conclude that the phase voltage and frequency of 3 phase generation source must be identical to that of distribution system source to maximize the power quality. Also, special attention is required in case of having load group or non-load group to 3 phase generation source.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.265-267
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• 2002

In this paper, the communication between Over-Current Relay agents is realized using DNP(Distributed Network Protocol), which is the standard communication protocol of distribution automation system in KEPKO. The key words in OCR agent communication are defined and represented by use of DNP application function code. And the DNP index for OCR agent is defined. The proposed communication scheme is tested by use of Communication Test Harness, a test tool for DNP protocol to show its soundness.

• Transactions on Electrical and Electronic Materials
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• v.17 no.2
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• pp.57-68
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• 2016

In this study, we present the modern hybrid system based power generation for electric vehicle applications. We describe the hybrid structure of modified current source based DC - DC converters used to extract the maximum power from Photovoltaic (PV) and Fuel Cell system. Due to reduced dc-link capacitor requirement and higher reliability, the current source inverters (CSI) better compared to the voltage source based inverter. The novel control strategy includes Distributed Maximum Power Point Tracking (DMPPT) for photovoltaic (PV) and fuel cell power generation system. The proposed DC - DC converters have been analyzed in both buck and boost mode of operation under duty cycle 0.5>d, 0.5<d<1 and 0.5<d for capable electric vehicle applications. The proposed topology benefits include one common DC-AC inverter that interposes the generated power to supply the charge for the sharing of load in a system of hybrid supply with photovoltaic panels and fuel cell PEM. An improved control of Direct Torque and Flux Control (DTFC) based induction motor fed by current source converters for electric vehicle.In order to achieve better performance in terms of speed, power and miles per gallon for the expert, to accepting high regenerative braking current as well as persistent high dynamics driving performance is required. A simulation model for the hybrid power generation system based electric vehicle has been developed by using MATLAB/Simulink. The Direct Torque and Flux Control (DTFC) is planned using Xilinx ISE software tool in addition to a Modelsim 6.3 software tool that is used for simulation purposes. The FPGA based pulse generation is used to control the induction motor for electric vehicle applications. FPGA has been implemented, in order to verify the minimal error between the simulation results of MATLAB/Simulink and experimental results.

• Journal of the Korean Society of Visualization
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• v.8 no.2
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• pp.51-55
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• 2010

Flow characteristics of a free-horizontal-axis-turbine (FHAT) current power generation system have been investigated by the use of a volumetric PTV. Three types of FHAT system (S50, SE50, S65) have been tested under the current speed 1.35 knot, 1.5 knot and 2 knot. The width of the blade installed around the body is 50 mm. Based upon the power generation characteristics of the FHAT, the flow features of the blade have been investigated. Among the three models it has been verified that the S65 is the most appropriate for power generations.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.95_96
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• 2009

In this paper, a new algorithm of Integrated Volt/Var Control (IVVC) is proposed using Volt/Var control for the Distribution Automation System (DAS) based on the modeling of the distributed load and the distributed current. In the proposed, the load flow based on the modeling of the distributed load with Distributed Generation and the distributed current are estimated from constants of four terminals using the measurement of the current and power factor from a Feeder Remote Terminal Unit (FRTU). For Integrated Volt/Var Control (IVVC), the gradient method is applied to find optimal solution for tap and capacity control of OLTC (On-Load Tap Changers), SVR (Step Voltage Regulator), and SC (Shunt Condenser). What is more Volt/Var control method is proposed using moving the tie switch as well as IVVC algorithm using power utility control. In the case studies, the estimation and simulation network have been testified in Matlab Simulink.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1674-1676
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• 2003

The factors affecting the accuracy of lightning current measuring system are figured out the materials and length of down-conductor, and impedance matching between grounding resistance and characteristic impedance of cable. The cable with the low characteristic impedance used to transfer the lightning current from the top of the tower is too long to measure the waveform of lightning current, exactly. Especially, the height of the tower can cause the change of front time and magnitude of lightning stroke current. Basically, in this experiment. It was found that the magnitude and rise time of the lightning current are extremely dependant in the length of down-conductor in lightning current measuring system.

• Journal of Information Processing Systems
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• v.18 no.6
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• pp.784-793
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• 2022

Grid-connected distributed power generation has been widely used in green energy generation. However, due to the distributed characteristics, distributed power generation is difficult to be dynamically allocated and monitored in the electrical control process. In order to solve this problem, this research combined the Internet of Things (IoT) with the automatic control system of electrical engineering to improve the control strategy of the power grid inverter according to the characteristics of the IoT system. In the research, a connection system of the power grid inverter and the IoT controller were designed, and the application effect was tested by simulation experiments. The results showed that the power grid inverter had strong tracking control ability for current and power control. Meanwhile, the electrical control system of the IoT could independently and dynamically control the three-phase current and power. The given value was reached within 50 ms after the step signal was input, which could protect the power grid from being affected by the current. The overall system could realize effective control, dynamic control and protective control.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.130-133
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• 2006

It is well-known that the resources for tide and tidal current energy are abundant in Korea. The south coast in Korea is recognized as one of the most appropriate places in the world for developing tidal current energy. The target site for harnessing tidal current energy is the Uldolmok, where the strongest tidal current in Korea occurs. In order to commercialize and industrialize the tidal current power generation, the construction of pilot tidal current power plant of 1MW has been started in April 2006, and is expected to be completed by May 2007. Extensive works including field investigation, field experiment for evaluating the efficiency of helical turbine and numerical analysis have been performed. This paper present the several design parameters for constructing the Uldolmok pilot tidal current power plant.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.673-676
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• 2001

The photovoltaic power generation system has a great future as clean energy instead of fossil fuel, which has many environmental problems such as exhausted gas or air pollution. In a utility interactive photovoltaic generation system, a three phase inverter is used for the connection between the photovoltaic array and the utility. This paper presents a three phase inverter for photovoltaic power system with current controller, voltage controller, PLL control system and the phase detector of interactive voltage by using dq transformation. The proposed inverter system provides a sinusoidal ac current for domestic loads and the utility line with unity power factor.