• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.481-482
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• 2013

This paper presents the method to determine the battery capacity for controlling the wind power with BESS for stabilizing the output of HanGeong wind farm in accordance with grid codes for distributed generators in Jeju Island. To find appropriate capacity of BESS, three kinds of simulations are carried out : There are focused on smoothing control, the frequency fluctuation and the renewable energy resources standards, respectively. As the simulation result, maximum C-rates of BESS for the wind farm are calculated as 2C, 5C and 2C that are for each method and battery capacities have 25%, 20% and 10% of total capacity of HanGeong wind farm. Finally, simulations for this paper are carried out by using PSCAD/EMTDC.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.5
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• pp.343-349
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• 2020

This study proposes a new single inductor converter for DC grid systems. A conventional system is composed of two independent converters for controlling battery and load. This system is simple but it has two inductors that affect power density and efficiency. The proposed converter can reduce the number of inductors by integrating the two converters and relieve voltage stress on switches by using a battery switching cell. Accordingly, power density and efficiency can be improved using a single inductor and lower voltage-rated switches. A prototype of a 500 W converter is built, and each mode is experimented on to confirm the validity of the proposed converter.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.3
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• pp.397-408
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• 1994

In this paper, a novel concept for a static three-phase to three-phase power converter for an AC drive with a unity power factor and reduced harmonics on the utility line is presented. The power circuit consists of two back-to-back connected six-pulse bridges having only a $\mu$F ceramic capacitor in the DC link. By controlling the active kpower balance between two bridges, the DC link voltage can be maintained within 20V deviation from the nominal value with the small ceramic capacitors regardless of the load variation even in the unbalanced source condition.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.6
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• pp.631-637
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• 2002

Two stroke low speed diesel engines are used as a power supplier not only for marine vessel but also diesel power plant with a benefit of its higher mobility and durability than the other thermal engines. However, there are some disadvantages such as the bigger vibrating excitation forces generated by high combustion pressure in cylinders which various kinds of vibrations are caused. In this paper, it is theoretically studied to control engine body vibration using dynamic vibration absorber. As an actual case, dynamic absorbers are designed for controlling X-mode vibration of 9K80MC-S engine on the diesel power plant and its performance is identified by the vibration test both in shop and site

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.8
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• pp.629-634
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• 2009

In this paper, drying mechanism is analyzed for improving the energy efficiency of an electric clothes dryer which consumes more electric power than other appliances. For the purpose, characteristic curves of the dryer such as temperature, relative humidity, evaporation rate, mass transfer coefficient, remaining moisture content curves are experimentally obtained. Based on the experimental results and analysis of drying mechanism, the effect of power of a heater and heat loss on the power consumption of an electric clothes dryer are systematically presented. These results demonstrate the feasibility of controlling heat loss at the heater as well as the backduct component to decrease the power consumption of an electric clothes dryer.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2262-2267
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• 2008

In this paper, drying mechanism is analyzed for improving the energy efficiency of an electric clothes dryer which consumes more electric power than other appliances. For the purpose, characteristic curves of the dryer such as temperature, relative humidity, evaporation rate, mass transfer coefficient, remaining moisture content curves are experimentally obtained. Based on the experimental results and analysis of drying mechanism, the effect of power of a heater and heat loss on the power consumption of an electric clothes dryer are systematically presented. These results demonstrate the feasibility of controlling heat loss at the heater as well as backduct component to decrease the power consumption of an electric clothes dryer.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.3
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• pp.254-262
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• 1990

In the active power filter, the PWM method for controlling the power converter plays an important role for the performance and the efficiency of the filter. In this paper, a new PWM method for the single phase current source type active power filter is presented, which is intended particularly for obtaining the maximum efficiency of the compensation. This method is basically based upon the optimized injection method, but in contrast to the existing method, this method adapts the optimized injection method by putting not only the pulse width, but also the pulse position into control variables. By doing this, when the number of pulses per one cycle is N, lower order harmonics up to the Nth order can be completely eliminated by the filter. So, this method is much more efficient than any other existing method. These characteristics are well verified by the computer simulations and the experiments.

• Journal of Power Electronics
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• v.16 no.1
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• pp.142-152
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• 2016

Common mode voltage (CMV) generation is a major problem in switching power converter fed induction motor drive systems. CMV is the zero sequence voltage generated due to the switching action of power converters. Even a small magnitude of CMV with a high rate of change may circulate large bearing currents which may damage a machine's bearings and shorten its life. There are several methods of controlling CMV. This paper presents 3-level sinusoidal pulse width modulation based techniques to control the magnitude and rate of change of CMV in multilevel AC-DC-AC drive systems. Simulation and experimental investigations have been presented to validate the performance of proposed technique to control CMV in 3-level neutral point clamped inverter based AC-DC-AC system.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.419-420
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• 2015

In this paper, a low-cost single-phase PWM rectifier with small DC-link capacitors is proposed, where a buck-boost converter with a low power rating is added at the DC link. By controlling the auxiliary circuit so as to absorb the voltage ripple in the DC link, the second-order voltage ripple in DC-link capacitor can be reduced significantly. Therefore, a small film capacitor can be utilized to replace the bulky electrolytic capacitors. The simulation results are shown to verify the validity of the proposed method.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.695-697
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• 1993

In this paper, a novel concept for a static three-phase to three-phase power converter for an AC drive with an unity power factor and reduced harmonics on the utility line is presented. The power circuit consists of two back-to-back connected six-pulse bridges having only a $5{\mu}F$ ceramic capacitor in the DC link. By controlling the active power balance between two bridges, the DC link voltage can be maintained within 20V deviation from the nominal value with the small ceramic capacitor regardless of the load variation even in the unbalanced source condition.