• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.1
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• pp.36-43
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• 2017

This paper describes a hybrid multi-output three-level DC/DC converter suitable for a wide, high-input voltage range of an auxiliary power supply for a high-power photovoltaic generating system. In a high-power photovoltaic generating system, the solar panel output voltage depends on solar radiation quantity and varies from 450Vdc to 1100Vdc. The proposed hybrid multi-output three-level DC/DC converter, which is an auxiliary power supply, would be used as power source for control printed circuit boards and relay and cooling fans in a high-power photovoltaic generating system. The proposed multi-output ($24V_{DC}/30A$, $230V_{DC}/5A$) hybrid three-level boost converter, which uses an energy recovery snubber, is controlled by variable-frequency and phase-shifted modulations and can achieve zero-voltage switching with all operating conditions of input voltage and load range. Experimental results of a 2kW prototype are evaluated and implemented to verify the performance of the proposed converter.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.659-663
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• 2012

The application of large power transformer into a power distribution system was inevitable due to the increase of power demand and distributed generation. However, the decrease of the power transformer's impedance caused the short-circuit current of the power distribution system to be increase thus, the higher short-circuit current exceeded the cut-off ratings of the protective devices such as circuit breaker. To solve these problems, several countermeasures have been proposed to protect the power system effectively from higher fault current and the superconducting fault current limiter (SFCL) has been expected to be the promising countermeasure. In spite of excellent current limiting performances of the SFCL, on the other hand, the efforts to apply the SFCL into power system has been delayed due to both the limited spaces for the SFCL's installation and its long recovery time after the fault removal. In order to solve these problems, a hybrid SFCL, which can perform either first half cycle limiting of first half cycle non-limiting operation, has been developed by corporation of LSIS (LS Industrial System) and KEPCO (Korea Electric Power Corporation). In this paper, we tried to requirements hybrid SFCL by PSCAD/EMTDC. Simulation results of our analysis of the hybrid SFCL is that its accompanied the characteristics both the limit the fault current and quick recovery caused by the less impact from superconductor.

• Proceedings of the KWS Conference
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• 2003.05a
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• pp.81-83
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• 2003

The potential advantages of the hybrid welding process are improved weld penetration, enhanced gap tolerance, control of weld metal composition, and improved weld quality in comparison to laser or arc welding. Especially, the deep penetration of hybrid welding is very attractive in welding of thick plates. In this study, therefore, the influence of arc power in hybrid welding on detailed bead dimensions at different laser power levels was investigated.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.307-311
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• 2004

In this study, a novel hybrid vehicle is proposed. The vehicle has a flywheel-engine hybrid system. Flywheels are more effective as energy charge systems than electric batteries in a respect of output power density. However, transmissions to effectively drive flywheels are very complex systems such as CVTs (Continuously Variable Transmissions). In the proposed hybrid vehicle, Constant Pressure System is employed, which is hydraulic power transmission. Using Constant Pressure Systems, hydraulic CVTs are easily realized with variable displacement pumps/motors. In this paper, firstly, the proposed flywheel hybrid vehicle making use of Constant Pressure System is described. Secondly, fuel consumption characteristics of the flywheel hybrid vehicle are experimentally examined with the stationary test facility, which employs a flywheel as a load emulating vehicle inertia. Finally, the experimental results and discussions are described. Fuel consumption of 26km/L is expected for 10 mode driving schedule with vehicle mass of 1500kg.

• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2547-2555
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• 2023

Amberlite IRN-78 resin was incorporated with iron to make a hybrid resin for the removal of silica from the borated water of nuclear power plants. The hybrid resin contained 0.84 wt % iron compounds upon pyrolysis. In batch experiments carried out at room temperature, 1 g of the hybrid resin removed ~60 ㎍ silica from 1 ppm borated water in ~120 min. The efficiency of the hybrid material increased with the resin quantity, decreased with silica concentration, and remained unchanged at different pH values. Freundlich and Temkin isothermal adsorption dominated the silica removal process and followed the pseudo-first-order and intra-particle diffusion mechanism simultaneously. The concentration of the leached iron remained appreciably under the safe limits of 200 ㎍/l during the experiments. This detailed study suggests the use of hybrid resin for the removal of silica from borated water streams and other similar systems.

• Journal of Auto-vehicle Safety Association
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• v.10 no.2
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• pp.36-42
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• 2018

UNECE/WP29/GRPE/EVE has recently defined that the power of a hybrid electric vehicle is the system power. Although a method for measuring the maximum power of a hybrid electric vehicle is presented by KATRI, it does not consider charging and discharging characteristics of traction batteries. This study provides a maximum power measurement method which reflects the charging and discharging characteristics of traction batteries in NOVC-HEVs (Not Off Vehicle Charging-Hybrid Electric Vehicles). Both methods are compared with regard to the output measurement results.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.7
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• pp.799-806
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• 2013

As a first step to develop the hybrid power generation system, on this study, the time-variable resources of wind and solar radiation of Yeongdo, Busan, Korea had been measured during June and July 2013. And the quantity of generated wind power and solar photovoltaic had also been measured during the same period. It is found out that the wind mainly flew from southwest at the average speed of 2 m/s during 2 months. And it is clear that, because of the low wind velocity, the wind quality to generate the power seems not enough at this area. Meanwhile solar radiation was measured every daytime (6:00~19:00) and the peak solar radiation occurred around 12:00~14:00. And it is clear that the time-based variations of quantity of generated power were proportional to the variations of these resources, respectively. As a proposal, these 2 natural energies can be combined as resources of a hybrid system, because these 2 patterns are not overlapped so much on time base.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11b
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• pp.33-37
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• 2004

Photovoltaic energy and wind energy are highly dependent on the season, time and extremely intermittent energy sources. Because of these reasons, in view of the reliability the photovoltaic and the wind power generation system have many problems(energy conversion, energy storage, load control etc.) comparing with conventional power plant. In order to solve these existing problems, hybrid generation system composed of photovoltaic(500W) and wind power system(400W) was suggested But, hybrid generation system cannot always generate stable output due to the varying weather condition So, the auxiliary power compensation unit that uses elastic energy of spiral spring was added to hybrid generation system for the present study. It was partly confirmed that hybrid generation system was generated a stable outputs by spiral spring was continuously provided to load.

• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.49-55
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• 2010

A series hydraulic hybrid vehicle(SHHV) concept has been explored as a potential pathway to an ultra-efficient city vehicle. Improvements in SHHV fuel economy with reduced emissions strongly depend on their supervisory control strategy. Thermostatic control is simple and reliable but it's cause of frequent engine on-off. Therefore, power follower strategy is presented. In this paper, thermostatic control strategy and power follower strategy is compared for the SHHV model developed using AMESim.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.473-474
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• 2013

In this paper, a power flow control of PV hybrid module system with ESS is proposed. Photovoltaic(PV) hybrid module system is consist of individual converter, central inverter, and energy storage system(ESS). Because PV power can be changed in particular hours and environment condition, the power management control for ESS is required. In this paper, the power flow control method for PV hybrid module system with ESS is proposed. The validity of proposed control method is verified by simulations and theoretical analysis.