• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.73-76
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• 2003

This paper proposes a maximum output power control of grid-connected wind power generation system using cage-type induction generators. For generator control, indirect vector control is used, where d-axis current controls the excitation level and q-axis current controls the generator speed. The generated power flows into the utility through the grid-side converter, by which the do link voltage is controlled to be constant and the ac current is controlled in sinusoid and. The generator speed is adjusted according to wind speed for extracting maximum power generation. Experimental results are shown to verify the validity of the proposed scheme.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.91-93
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• 2008

A Buoyant Hybrid Power Generation System (BHPGS) described in this paper, is a conceptual approach to a hybrid solar-wind power generation in the near sea. The primary purpose of the BHPGS is given to improve utilization of solar cell modules. Main components of the BHPGS include a solar cell module, buoyant object, power generator, and support assembly including weight. Components such a generator controller, DC/AC converter, etc., are not configured in the current BHPGS because they can easily be purchased as a commercial-off-the-shelf product. In addition, some of the BHPGS applications are discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.279-280
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• 2008

Accelerated aging tests were conducted under laboratory conditions on two generator stator bars. Electrical stress is applied in No. 1 model stator bar. Electrical and thermal stresses are applied in No. 2 model stator bar. As aging times increased from 0 to 4780h, diagnostic tests were performed on No. 1 and No. 2 model stator bars. Diagnostic tests included AC current, dissipation factor(tan$\delta$) and partial discharge magnitude. The ${\Delta}tan{\delta}$ and $\Deta$I of No. 1 and No. 2 model stator bars increased with increased in aging time.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.761-768
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• 2018

In this paper, the performance analysis of a control topology based on the direct output power control (DPC) for robust and inexpensive permanent magnet-assisted synchronous reluctance generator (PMa-SynRG) system is presented. The PMa-SynRG might be coupled to an internal combustion engine running at variable speed. A three-phase PWM rectifier rectifies the generator output and supplies the dc link. A single-phase PWM inverter supplies constant ac voltage at constant frequency to the grid. The overall control algorithm is implemented on a TMS320F2812 digital signal processor board. Simulations results and experimental results verify the operation of the proposed system.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.209-212
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• 2003

The superconducting generator and motor have many advantages over the conventional machines. The better characteristics originates from the higher magnetic field density by way of superconducting field coil which conducts the operating current with very large density. The major merits of the superconducting machines can be explained as the smaller size and weight as well as the higher efficiency. The compactness would be very useful for the applications such as ship propulsion motors and the higher efficiency is expected to play a good role in saving the electricity generation cost for the generators used in power plants. In spite of these advantages the main reason for the lazy commercialization is known as the expensiveness of the superconductors and the cryogenic systems. In this paper focusing on the superconducting generator, we will consider and estimate the economic effectiveness when the machines permeate into the actual AC generator market in Korea gradually.

• Journal of Electrical Engineering and Technology
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• v.2 no.1
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• pp.68-80
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• 2007

This paper covers switched reluctance generator (SRG) and its comparison with induction and synchronous machines for distributed generation. The SRG is simple in design, robust in construction, and fault tolerant in operation; it can also withstand very high temperatures. However, the performance and cost of the SRG power electronics driver are highly affected by the topology and design of the converter. IGBT and MOSFET based converters are not suitable for very high power applications. This paper presents thyristor-based resonant converters which are superior candidates for very high power applications. Operations of the converters are analyzed and their characteristics and dynamics are determined in terms of the system parameters. The resonant converters are capable of handling high currents and voltages; these converters are highly efficient and reliable as well. Therefore, they are suitable for high power applications in the range of 1MW or larger for distributed generation.

• Proceedings of the KIEE Conference
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• summer
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• pp.1124-1126
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• 2004

The measurements were performed to assess the insulation deterioration condition of the stator winding of Dae-Cheong hydro-generator ${\sharp}2$ which had been in service after being constructed 1980. After repair of the stator winding insulation. we conducted insulation diagnostic tests which include resistance, polarization index(P. I). AC current, dissipation factor($Tan{\delta}$) and partial discharges ($Q_{max}$). The results of diagnostic tests were compared to the previous records. On the basis of these test results. this paper tried to present the importance of insulation repair for the generator stator winding.

• Journal of Power Electronics
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• v.9 no.1
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• pp.43-50
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• 2009

This paper deals with a novel solid state controller (NSSC) for an isolated asynchronous generator (IAG) feeding 3-phase 4-wire loads driven by constant power prime movers, such as uncontrolled pico hydro turbines. AC capacitor banks are used to meet the reactive power requirement of the asynchronous generator. The proposed NSSC is realized using a set of IGBTs (Insulated gate bipolar junction transistors) based current controlled 2-leg voltage source converters (CC- VSC) and a DC chopper at its DC bus, which keeps the generated voltage and frequency constant in spite of changes in consumer loads. The neutral point of the load is created using aT-configuration of the transformers. The IAG system is modeled in MATLAB along with Simulink and PSB (power system block set) toolboxes. The simulated results are presented to demonstrate the capability of the isolated generating system consisting of NSSC and IAG driven by uncontrolled pico hydro turbine and feeding 3-phase 4-wire loads.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2072-2074
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• 2005

This test was performed to assess the insulation condition of the stator winding of 3.45kV hydro generator in insulation deterioration condition which was due to long service period(30years) since installed We extracted 12 stator wingdings from the hydro generator core, cut the stator windings into three parts(Middle winding part, slot winding part, end wingding part), and evaluated the insulation condition to know the deterioration condition of each parts. This insulation diagnostic tests include AC current, dissipation factor, and partial discharg test.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.861-863
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• 2003

In this paper, a controller for a non-contact bearing-based motor-generator system is designed. The levitation control method is a digital PID control. The plant dynamics consisting of actuator and rigid rotor dynamics are described. And some experiments are conducted with each global control and local control concept. From the whirl test, the Motor-Generator System can be controlled within about ${\pm}10{\mu}m$ gap variation at the rotational speed of 600rpm and generate electric power of AC100V.