• Journal of Energy Engineering
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• v.28 no.1
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• pp.65-72
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• 2019

The Korean government is aiming to produce 20% of the electricity using renewable energy sources by 2030. Ocean renewable energy sources which are abundant in South Korea can do an important role to achieve the goal. This paper introduces a tidal current energy converter utilizing flow induced vibrations which can efficiently work even in the currents slower than 1.0m/s and suggests optimal designs of the tidal energy converter based on speeds of the tidal currents in seven different coastal regions in South Korea. Moreover, the theoretical annual energy production by the tidal converter is estimated at theses costal areas. The total amount of the annual energy production by the tidal energy converter is predicted as 221.77 TWh which is equivalent to 42.3% of the electric consumption of South Korea in 2013. The result shows that the tidal current energy converter can be an important role to achieve the goal of the Korean government.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.159.2-159.2
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• 2011

Hyundai Heavy Industries has developed a tidal current energy converter utilizing the accumulated technology as the world largest constructor for ship and offshore structures. The model has two sets of turbines in both ends in order to utilize the bi-directional current flows in flood and ebb tide. The torque produced by turbine in tidal current is directly delivered to generator along the horizontal axis, in which the turbine, gear, generator, gear and turbine are connected successively. The manufactured model for field test has the turbine diameter of 5 meters to produce the maximum power of 500kW at maximum current speed of 5m/s. The technical verification of tidal power converter was performed by means of small scale model test in towing tank as well as field test at the Strait of Uldolmok located in Jindo of Jeollanamdo province. Field test was performed by mounting the tidal current converter on the SEP(Self Elevating Platform) which could lower the 4 vertical legs on the seabed and could elevate platform over the water surface using the hydraulic power for itself. The field test performed for a month shows that power output is similar or larger compared with the expected one in design stage. This paper presents the development of tidal current energy converter and real sea field test by Hyundai Heavy Industries. This project has finished successfully and provided the technical advance toward commercial services for tidal current power generation in the south-west region in Korea.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.644-647
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• 2007

We have developed electrical power train for 1MW tidal current plant which is composed of both 500kW tidal current plant with doubly-fed induction generator and 500kW tidal current plant with synchronous generator. To check performances of the protype, 2MW dynamometer is used to simulate a helical turbine, and then protype generator and converter are coupled with the dynamometer separately. From the suggested experimental results it is reconfirmed that two kinds of the power train to be installed at the Uldolmok located at southwestern shore in Korea are able to operate under all kinds of the condition about speed and power.

• New & Renewable Energy
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• v.9 no.4
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• pp.19-24
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• 2013

In order to analyze the characteristics of tidal current power generation system, we measured output power in M-G Set (Motor-Generator Set) and MATLAB/Simulink. We installed M-G Set (Motor-Generator Set) and did a simulation using MATLAB/Smulink. The simulation consisted of the tidal current turbine, PMSG, converter, and three-phase PWM inverter. Also, the speed control of the generator was performed using machine side converter. And we measured output voltage, current, power of the generator and the output power of three-phase PWM inverter.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.507_508
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• 2009

As a result of environmental concerns, renewable energy systems are rapidly increasing and particularly tidal current is a potential source of energy. In accordance with a large-capacity trend, doubly-fed induction generator is applied such as wind farms and tidal systems. In this paper, Optimal hysteresis band amplitude of CRPWM Converter is determined for improving rotor current waveform and electrical quality.

• New & Renewable Energy
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• v.9 no.1
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• pp.44-50
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• 2013

In order to analyze the characteristics of tidal current power generation system, we measured the output power according to the stream velocity by a water tunnel system and a simulation in MATLAB/Simulink. The water tunnel system consisted of impeller tidal flow transducer and PMSG with rotor in the water. The simulation consisted of PMSG, the tidal current turbine, and back-to-back converter. Also, we simulated the characteristics of output power according to the change of blade length and angular velocity.

• New & Renewable Energy
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• v.16 no.1
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• pp.31-40
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• 2020

Most countries in the world are trying to reduce the use of fossil fuels in the production of electricity and replace them with renewable energy technologies. In Korea, there are abundant ocean renewable energy sources that will play an important role in power generation in the future. This paper introduces a new tidal energy converter utilizing flow induced vibration (FIV), which can work efficiently, even in the currents slower than 1.0m/s. All tests were conducted at the Marine Renewable Energy Laboratory at the University of Michigan to examine the effects of the damping ratio of the electric generators on the power outputs and power efficiencies. In these tests, two identical circular cylinders were used, and passive turbulence controllers were applied to the surface of the cylinders to enhance the FIV. The experimental results showed that by using the two cylinders in the FIV, the power output and efficiency reached up to 31 W and 36%, respectively. In particular, the results showed that the power efficiency was higher at the relatively low flow speed (4

• The KSFM Journal of Fluid Machinery
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• v.13 no.2
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• pp.36-40
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• 2010

Tidal current power system is the energy converter which converts the kinetic energy of tidal stream into electric energy. The performance of the rotor which initially converts the energy is determined by various design factors and it should be optimized by the ocean environment of the field. Flow direction changes due to rise and fall of the tides, but horizontal axis turbine is very sensitive to direction of flow. To investigate the rotor performance considering the interaction problems with incidence angle of flow, series of experiments have been conducted. The results and findings are summarized in the paper.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.125-129
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• 2006

In order to transmit energy generated through the stator winding of a doubly-fed Induct ion generator (DFIG), we need to synchronize the generated voltage vector with the grid voltage vector. However, the existing synchronization method works only when the encoder is installed at a specific Position and equivalent constant is precise. In order to solve this Problem, a new synchronization method has been proposed and a way of applying the method to existing doubly-fed induction generator control algorithm has been also proposed. The validity of the proposed methods have been verified using a prototype converter for the control of a 1.5MW-class doubly-fed induction generator

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.1
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• pp.1-10
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• 2022

In this study, the two horizontal shroud tidal current energy converter, which can generate power even under low flow speed conditions, was developed. In order to determine the shape of the shroud system, a three-dimensional numerical simulation test was conducted, and a 1/6 scale down model was made to perform a hydraulic model experiment. The hydraulic model experiment was performed under four flow conditions, and the flow speed, torque, and RPM were measured for each experimental case. As a result of the numerical simulation test, it was found that the flow speeds passing through the nozzle were increased by about 2~3 times in the cylinder, and when the extension ratio was 2:1, the highest flow speed was shown. In addition, it was found that the flow speeds increased 2.8 times when the diameter ratio between the nozzle and the cylinder was 1.5:1. Meanwhile, as a result of the hydraulic model experiment, it was found that when the tip speed ratio was between 1.75 and 2, the power coefficient was 0.32 to 0.34.