• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.10
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• pp.1046-1052
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• 2007

Elastic-plastic structural analysis for regenerative cooling chamber of gas generator was performed. Uniaxial tension test was conducted for STS316L at room and high temperature conditions to get the material data necessary for the structural analysis of the chamber which was operated under thermal load and high internal pressure. Physical properties including thermal conductivity, specific heat and thermal expansion were also measured. The structural analysis for four different types of regenerative cooling chamber of gas generator revealed that increased cooling performance decreased the thermal load and strain of the cooling channel structure. The results propose that in order for the regenerative cooling gas generator chamber to have high structural stability with endurance to high mechanical and thermal loads, it is important for the chamber to be designed to have high cooling performance.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.802-807
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• 2007

Elastic-plastic structural analysis for regenerative cooling chamber of gas generator was performed. Uniaxial tension test was also conducted for STS316L at room and high temperature conditions to get the material data necessary for the structural analysis of the chamber which is operated under thermal load and high internal pressure. Physical properties including thermal conductivity, specific heat and thermal expansion data were also measured. The structural analysis for four different types of regenerative cooling chamber of gas generator revealed that increased cooling performance decreases the thermal load and strain of the cooling channel. The results propose that in order for the regenerative cooling gas generator chamber to have high structural stability with endurance to high mechanical and thermal loads, it is important for the chamber to be designed to have high cooling performance.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1819-1821
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• 1996

A compact size high voltage pulse generator with nanosecond rise time has been fabricated and investigated experimentally. It can be reduced the inductance of the generator by fixing the Marx generator components and pulse forming network components into a single cylindrical unit. As a result, it can be obtained nanosecond rise time about $8{\sim}10[ns]$ and pulse width of several hundred nanoseconds from the modified Marx pulse generator. And parametric studies showed that the rise time of the output pulse was depended little on the change of the load resister and the charging capacitor while the pulse width of the output pulse was depended greatly upon the change of the load resistor and the charging capacitor.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.7
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• pp.1195-1199
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• 2008

In this paper, peak detector of generator's output voltage and variable gain controller are introduced for a fast dynamic response. The conventional r,m.s, signal detected has inherent time delay, and the dynamic response of generator using conventional PID controller has some problem in sudden load change. In this paper, the peak detector and signal selector with variable gain controller is used to overcome this problem. The main controller can check the voltage state from the peak detector. When a sudden load change, the over-voltage and under-voltage signal from peak detector change the controller's gain and exciter's current reference. The proposed scheme can improve the dynamic response, which is verified from experimental test of 200kW diesel engine-generator.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.7
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• pp.329-333
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• 2001

The pulsed poser system has been widely used to many applications, such as E/P(Electrostatic Precipitator), DeNox/DeSOx power system, ozon generator, etc. A pulse energy efficiency for load depends on the rising time, peak value, pulse duration and impedance matching, etc. The pulse generator generally required for short pusle duration and high peak value was forced to consider its volume and economy. In this study, developing a compact pulse generator that applied for cascading method to be made of two pulse transformers, we compared cascading voltage with non cascading one by applying the pulse energy to load. Adopting cascading technique to pulse transformer, we found that average cascading voltage was about 60[%] of theoretical value. Maximum cascading ratio was calculated at 60 times compared with non cascading voltage.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.74-75
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• 2017

This paper proposes a control scheme of the voltage ripple suppression for the permanent magnet exciter generator. The output voltage of the permanent magnet excitation generator is affected by the field current, load current and the engine speed. The engine speed can be controlled by the governor. But, the actual frequency is changed at the starting and a sudden load variation. As a result, output voltage overshoot and undershoot can decrease the power quality in the grid system. The proposed control scheme uses a frequency factor to control the field current of the generator for the voltage ripple reduction. Because of the linkage flux is proportional to the frequency, the instantaneous frequency can consider the linkage flux. The proposed control method shows the improved control performance for the permanent magnet excitation generator through simulation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.4
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• pp.383-387
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• 2008

This paper analyzes the operation characteristics of a self excited induction generator with Steinmetz connection. For this analysis, the symmetrical components analysis is used to obtain the related expressions and the excitation capacitance and the magnetizing reactance are determined in turn by the condition of self excitation which includes the input impedance of the generator as viewed across load terminals. Two simultaneous equations of the condition of self excitation itself are solved by using the real and imaginary function in an application software. This method is applied to simulate the operation characteristics when the generator is driven at rated speed and the specified excitation capacitor is connected across the lagging phase. The results show that better operation characteristics except generated frequency are obtained by using relatively large excitation capacitance and resistive load.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5D
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• pp.689-695
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• 2011

In this paper, available power generation on the road from renewable energy technologies on how to use the piezoelectric effect has been studied. A lot of vehicles on road that can generate electricity using renewable energy technology as part of the external shock to convert the load into electrical energy using piezoelectric effect piezoelectric generator can be applied to road space. Piezoelectric power harvesting using piezoelectric ceramics for the development of impact load characteristics were tested as function of various experimental design such as generator design and array of piezo-ceramic. To design the piezoelectric generator, the characteristics of piezoelectric ceremic were compared depending on the type of impact load as function of impact load, shock-absorbing.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.423-426
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• 1999

This paper describes a driving scheme of the series hybrid electric vehicle that we have developed. Both series HEV and parallel HEV are well known. We chose series HEV because it provides good energy efficiency in urban driving and operates in all-electric mode in performance. And engine-Generator is driven at constant speed with constant load to maintain the low emission. And the battery supplies power during high-load and receive energy during low-load

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.949-951
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• 2002

Permanent-magnet (PM) synchronous generator is feasible for use with a wind turbine, because the generator for wind power requires variable-speed generation, light weight, and high torque. In this paper, basic design and construction of an axial-flux permanentmagnet generator with power output at 60 [Hz], 300 [r/min] for wind energy system is introduced. Finite-element method (FEM) is applied to analyze generator performance. In order to save time, equivalent analysis model is developed. The performance of the proposed generator at no-load and resistive load are compared, and power output and voltage at various speed and loads are compared as well. The results of FE analysis show that this PM generator is a useful solution for small-scale wind-turbine applications.