• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2011.10a
• /
• pp.75-75
• /
• 2011

This paper has been studied that ocean wave vibration power generator is composed of buoy and vibration generator to make effective use of ocean wave energy. We designed buoy to can occur resonance for dominant frequency with ocean wave. And then we fitted the natural frequency of vibration system with vibration power generator to buoy's natural frequency. And we can show that the amplitude of ocean wave up and down motion is decreased, on the other hand, the displacement of vibration system with vibration power generator is increased. Therefore, ocean wave vibration power generator which is proposed in this paper has merits not only securing its stability from surroundings but also producing more electronic power by using ocean wave energy.

• Journal of Drive and Control
• /
• v.12 no.2
• /
• pp.7-13
• /
• 2015

In this study, we suggested the wave power generator using horizontal motions of the wave for use in the coastal sea. The length of the horizontal movement of the wave in the vicinity of the sea surface is larger than the length of the vertical reciprocating movement of the wave, hence the proposed device has a wave power transmission plate. In addition, because the motion of the wave is maximum to the sea surface, by arranging the buoyancy tanks at the top of the wave power transmission plate, it is always capable of vertical movement in accordance with the sea surface. To confirm the usefulness of the proposed wave power generator, we constructed a mathematical model of the wave power generator and carried out simulation using bondgraph. Furthermore, the efficiency was verified by measuring the degree of electrical energy production through a preliminary experiment.

• Journal of the Society of Naval Architects of Korea
• /
• v.59 no.6
• /
• pp.439-446
• /
• 2022

Efforts to reduce carbon dioxide(CO₂) emissions are being carried out due to climate environmental problems. Eco-friendly ships are also being developed, and various energy saving measures have been developed and applied. In ships, researches have been conducted in various fields such as electric propulsion system and energy saving devices. In addition, the development of ships using various renewable energy, such as kite using wind power and wind power generation, has been carried out. This paper proposes a plan to use renewable energy for ships by applying wave generators to small ships. In 2016, 130 small domestic ships drifted by sea due to discharge of starting storage batteries, and discharge cases accounted for the largest portion of the causes of domestic ship accidents. This is due to the excessive use of storage batteries for starting the main engine by departing in a weak storage battery state for small ships. Accordingly, two type wave power generators - opened flow wave power generator and enclosed vibrator type wave power generator - are developed for charging a starting storage battery when the ships are stationary at sea or port. Opened flow wave power generator utilizes the flow of fluid in the ship by using wave induced ship motion. Enclosed vibrator type wave power generator utilizes the pendulum kinetic energy located in a ship due to wave induced ship motion.

• Journal of Magnetics
• /
• v.18 no.3
• /
• pp.250-254
• /
• 2013

In this research, the linear electrical generator in wave energy farm utilizing resonance power buoy system is studied. The mechanical resonance characteristics of the buoy and the wave are analyzed to maximize the kinetic energy in a relatively small wave energy area where WRPS is operated. In this research, we chose an analog model of the linear electrical generator of which size is one-hundredth of an actual size of it in WPRS (Wave energy farm utilizing Resonance Power buoy System) prior to verifying the characteristics of actual model of linear electrical generator in WRPS. In addition, the finite element analysis is conducted using commercial electromagnetic analysis software named MAXWELL to examine the electric characteristic of linear generator. Finally, for the verification of dynamic and electric characteristics of linear generator, the prototype was manufactured and the experiments to measure the displacement and the output electric power were performed.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.8
• /
• pp.391-399
• /
• 1999

We have designed the backward wave oscillator, a power-pulsed generator oscillated at 20 GHz has higher frequency than current one. An absolute instability linear analysis was used for the purpose of designing the slow wave structure. A large diameter (D/$\lambda$=4.8) of the slow wave structure was adopted to prevent the breakdown brought about by the increase of power density. We have fabricated a marx generator, pulse forming line and diode. And the development of a compact pulsed power generator with short period and low amplitude is expected.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.74.5-74
• /
• 2001

The wave power plant is a generating system to convert the wave energy resources to electric energy. ´CHUJEON A´, which is a prototype of wave power plant developed by KORDI(Korea Ocean Research and Development Institute), has been launched for its performance test. A wound rotor induction machine is adopted as a generator for the power plant to acquire constant frequency and voltage over wide range of rotor speed. Because the generator of ´CHUJEON A´ has no connection to the power grid line on land, all of the processes to generate and consume the electricity have to be conducted on the floating plant. This paper deals with the design and implementation of the unmanned control system for ´CHUJEON A´. The system includes generator control system, power conversion and charging system, data acquisition and wireless communication system ...

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.3
• /
• pp.401-409
• /
• 2023

Oscillating water column (OWC) type wave power generator system is a power generation system that uses wave energy, a sustainable and renewable energy source. Irregular cycles and wave heights act as factors that make it difficult to secure generation efficiency of the wave power generator system. Recently, research for improving power generation efficiency is being conducted by applying digital twin technology to OWC type wave energy converter system. However, digital twin using sensor data can predict erroneous performance due to uncertainty in the sensor data. Therefore, this study proposes an uncertainty analysis method for sensor data which is used in digital twin to secure the reliability of digital twin prediction results. Uncertainty quantification considering sensor data characteristics and future uncertainty information according to uncertainty propagation were derived mathematically, and confidence interval estimation was performed based on the proposed method.

• Journal of information and communication convergence engineering
• /
• v.7 no.2
• /
• pp.209-214
• /
• 2009

The employment of the induction generator is preferable in the natural energy utilization by the minimum maintenance and the mechanical robustness, Another merit is also expected when it is connected to the power network system, because constant-voltage and constant frequency (CVCF) power generation is easily realized in spite of the variation of the rotor speed. However the induction generator needs much amount of the reactive power that reduces power factor in the primary side. The improvement of power factor in the primary side requires large VAR compensator, this point is solved, the merit of the induction machine as a main generator will become more established. This paper proposes a novel approach where the secondary is controlled by a PWM inverter not only to get CVCF power but also to improve the primary power factor. Basically the inverter is controlled so that the field current is supplied from the secondary side in this approach. The required capacity of the inverter is small, because only the slip power is controlled in the secondary side. In the experimental system where the sea wave torque simulator is used, the power factor is well improved by the microcomputer controlled PWM inverter.

• Journal of information and communication convergence engineering
• /
• v.7 no.1
• /
• pp.46-51
• /
• 2009

In this paper, the two-axis theory is adopted to analyze the secondary excited induction generator applied to random wave input generation system. The analysis by the two-axis theory helps to know the transmitted power of the induction machine. The electric variables, like as primary and secondary currents, voltages, and electric output power, were able to express as equations. These equations are help to simulate the generation system numerical model and to know the transient state of the system. As it is preferred to stabilize the output voltage and frequency in the constant level, microcomputer controlled VSI connected to the secondary windings supplies the secondary current with slip frequency. For testing the appropriateness of this method, the input torque simulator in the laboratory to drive the secondary excited results show the advantage of secondary excited induction generator system for the random input wave generation system.

• Transactions on Electrical and Electronic Materials
• /
• v.12 no.4
• /
• pp.152-155
• /
• 2011

This paper presents a comparative analysis on step and the touch voltages generated by either a sine and a ring wave voltage generator; this analysis was done as a basic study in order to develop a small and lightweight ground meter. A ring wave generator using pulsed power technology was fabricated; an experimental grounding system specified in Institute of Electrical and Electronics Engineers standards 80 and 81 was installed. The step and the touch voltages, which were measured using comparable a sine and a ring waves in terms of magnitude and frequency, were equal. Using pulsed power technology, the weight of the fabricated ring wave generator could be reduced to one-fifth of that of a sine wave generator. Consequently, if a ground meter adopts the ring wave instead of a sine wave, it will be possible to reduce the weight of a ground meter and improve the efficiency of measurement.