• Journal of Power Electronics
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• 제16권4호
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• pp.1612-1620
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• 2016

This paper presents the dynamic excitation control of a siphon-turbine coupled pico-hydro powered cage rotor induction generator and load matching for off-grid electricity generation. Through the proposed dual-role of the current-controlled voltage source converter (VSC), acting as static synchronous compensator and load controller, real and reactive power are dynamically controlled in a decoupled manner with a self supported DC-bus. The proposed scheme entails minimal computation for ensuring the rated (set) capacity of real power. The scheme also exhibits fault immunity for protection, thus enabling the effective handling of constant power electrical loads presented by base telecom station towers in remote locations. The performance of the system is evaluated under MATLAB/Simulink and is experimented through a developed hardware prototype. Simulation and experimental results show close conformity and validate the effectiveness of the proposed scheme.

• Journal of electromagnetic engineering and science
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• 제9권2호
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• pp.53-60
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• 2009

Remarkable developments in the electric and electronic industry have given people's daily life much more convenience and abundance. However, in electrical communication, or electric and electronic fields, making electrical and electronic devices more functional, more integrated, and faster have put electromagnetic interference(EMI) into more complex forms, and lots of problems such as interruption, malfunction, or interference by noise between electrical communication systems occurs every day. In this research, the electromagnetic compatibility(EMC) filter in the high powered breaker was designed and fabricated as a counter measure. The filter attenuated noise more than 20${\sim}$50 dB in the range of 10 MHz${\sim}$1.5 GHz. And, when the electric fast transient(EFT) of 4 kV in the level 4 of IEC 61000-4-4 was induced, it was soon suppressed to 600 V.

• 전기의세계
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• 제24권6호
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• pp.85-91
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• 1975

A new design method for the SCR-Chopper type speed controller of the battery-powered vehicles was developed. The conventional speed-controllers were either inductance type or contact type using resistance. In the new method, a photocoupler was used in sensing the control currents and a noncontacting type photo-conductive device (CDS) was used in mading acceleration. Experiments using these new devices showed encouraging results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.712-714
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• 1998

Fuel cell systems offer high energy efficiencies for transportation application. In addition, they can use alcohols and alternative fuels as the fuel, while producing little or no noxious emissions. Fuel cell-powered vehicles should be competitive in performance characteristics and in capital and maintenance costs with internal combustion engine vehicles. The objective of the present study is to design a fuelcell/battery powered vehicles to analyze technical feasibity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1975년도 제6차 하계학술발표회 및 산학협동세미나 초록
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• pp.79-82
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• 1975

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.220-221
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• 2008

With recent advanced in portable electric devices, wireless sensor, MEMS and bio-Mechanics device, the new typed power supply, not conventional battery but self-powered energy source is needed. Particularly, the system that harvests from their environments are interests for use in self powered devices. For very low powered devices, environmental energy may be enough to use power source. Therefore, in other to made piezoelectric energy harvesting device. The made 31 type triple-morph cantilever was resulted from the conditions of 100k$\Omega$, 0.25g, 154Hz respectively. The thick film was prepared at the condition of $6.57V_{rms}$, and its power was $432.31{\mu}W$ and its thickness was $50{\mu}m$.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권8호
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• pp.347-353
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• 2002

This paper presents an accurate method for measuring the ground resistance in powered grounding system. Most of substations and electric power equipments are interconnected to an extensive grounding network of overhead ground wires, neutral conductors of transmission lines, cable shields, and etc. The parasitic effects due to circulating ground currents and ground potential rise make a significant error in measuring the ground resistance. The test current transition method was proposed to reduce the effects of stray ground currents, ground potential rise and harmonic components in measurements of the ground resistance for powered grounding systems. The instrumental error of the test current transition method is decreased as the ratio of the test current signal to noise(S/N) increases. It was found from the test results that the proposed measuring method of the ground resistance is more accurate than the conventional fall-of-potential method or low-pass filter method, and the measuring error was less than 3[%]when S/N is 10.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.1039-1042
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• 2005

Recently, a considerable number of studies have been made on the $RFID^{[1-6]}$ systems. RFID is a technique of identifying an object using radio frequency transmission. The technology can be used to identify, track, sort or detect a wide variety of objects. The RFID system is composed of two main elements: a reader and a tag. Tags can either be active (powered by battery) or passive (powered by the reader field). The passive tags communicate back to the reader with a technique called 'backscatter'. RFID technology can be applied to the supply chain, security, logistics industry and etc. Especially, UHF RFID is worth noticing because of its relatively long identification range and commercial UHF RFID systems are under development. In this paper, we designed and implemented a UHF RFID reader firmware for ISO/IEC 18000-6 Type B specification.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권5호
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• pp.220-229
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• 2004

We have examined a technique of one-dimensional (1D) fluid modeling for radio-frequency Ar capacitively coupled plasmas (CCP) between unequal-sized powered and grounded electrodes. In order to simulate a practical CCP reactor configuration with a grounded side wall by the 1D model, it has been assumed that the discharge space has a conic frustum shape; the grounded electrode is larger than the powered one and the discharge space expands with the distance from the powered electrode. In this paper, we focus on how much a 1D model can approximate a 2D model and evaluate their comparisons. The plasma density calculated by the 1D model has been compared with that by a two-dimensional (2D) fluid model, and a qualitative agreement between them has been obtained. In addition, 1D and 2D calculation results for another reactor configuration with equal-sized electrodes have also been presented together for comparison. In the discussion, four CCP models, which are 1D and 2D models with symmetric and asymmetric geometries, are compared with each other and the DC self-bias voltage has been focused on as a characteristic property that reflects the unequal electrode surface areas. Reactor configuration and experimental parameters, which the self-bias depends on, have been investigated to develop the ID modeling for reactor geometry with unequal-sized electrodes.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.589-590
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• 2013

The fast development of electronic devices towards wireless, portable and multi-functionality desperately needs the self-powered and low maintenance power sources. The possibility to coupling the nanogenerator to wearable and portable electronic device facilitates the self powered device with independent and self sustained power source. Nanogenerator has ability to convert the low frequency mechanical vibration to electrical energy which is utilized to drive the electronic device [1]. The self powered power source has the ability to generate the power from environment and human activity has attracted much interest because of place and time independent. The human body motion based energy harvesting has created huge impact for future self powered electronics device applications. The power generated from the human body motion is enough to operate the future electronic devices. The energy harvesting from human body motion based on triboelectric effect has simple, cost-effective method [2, 3] and meet the required power density of devices. However, its output is still insufficient to driving electronic devices in continues manner so new technology and new device architecture required to meet required power. In the present work, we have fabricated the triboelectric nanogenerator using PDMS polymer. We have studied detail about the power output of the device with respect to different polymer thickness and varied separation distance.