• 전력전자학회논문지
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• 제22권5호
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• pp.457-462
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• 2017

This paper proposes a digital power control of the LLC resonant half-bridge inverter for high power microwave oven application. Conventional half-bridge inverter for driving a microwave oven uses a hardware-based power control method which varies the frequency according to the AC source voltage. In this case, it is difficult to control the output power according to the variation of the load status of magnetron. The proposed power control consists of an instantaneous current generator and a current controller. Instantaneous current generator makes an instantaneous current reference from power command using input voltage information. Current controller controls input current which has an information of status of magnetron. The proposed power control does not require any compensation algorithm for the change of the load status of the magnetron and change of input voltage. The validity of the proposed method for the control of the change of input voltage and frequency is verified by both simulation and experiment.

• 조명전기설비학회논문지
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• 제24권12호
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• pp.64-70
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• 2010

High capacity UPS and emergency generators are commonly employed at facilities where power interruption is not allowed. Nowadays, combinations of existing commercial incoming power and an emergency generator or combination of multiple generators and CTTS(Closed Transition Transfer Switch) is adopted sometimes for more reliable power supply. In this paper, application of CTTS and STS(Static Transfer Switch) to dual-power line is suggested for highly reliable uninterruptible power. By realizing such a system, construction of incoming power facilities, installation of emergency generator and large capacity UPS can be omitted, through which saving of the installation space and corresponding capital investment can be expected.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.192-196
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• 2001

These days, most of electric power facilities need high stability. Therefore integrated system has been required to monitor and control electronic power distribution system in fields at all times when the interruption of electric power has occurred. To construct this system, unit that convert and process the input signal from fields needed. And for control and monitoring from remote place MMI software is required. Lastly network equipments are required for real-time communications. So, in this paper, units for control and monitoring of emergency power generator and for electric power monitoring in normal electric power and interruption of electric power are developed. Also integrated remote system for monitoring in remote is developed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 추계학술대회
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• pp.167-168
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• 2018

Recently high magnetic flux is used for water treatment and medical treatment. The magnetic flux density reaches up to several Tesla. In this paper, high magnetic flux generator and detector are investigated. The target flux density is 7 Tesla. Proto-types are made and tested.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.96-97
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• 2012

In nitride and oxide film deposition, sputtered metals react with nitrogen or oxygen gas in a vacuum chamber to form metal nitride or oxide films on a substrate. The physical properties of sputtered films (metals, oxides, and nitrides) are strongly influenced by magnetron plasma density during the deposition process. Typical target power densities on the magnetron during the deposition process are ~ (5-30) W/cm2, which gives a relatively low plasma density. The main challenge in reactive sputtering is the ability to generate a stable, arc free discharge at high plasma densities. Arcs occur due to formation of an insulating layer on the target surface caused by the re-deposition effect. One current method of generating an arc free discharge is to use the commercially available Pinnacle Plus+ Pulsed DC plasma generator manufactured by Advanced Energy Inc. This plasma generator uses a positive voltage pulse between negative pulses to attract electrons and discharge the target surface, thus preventing arc formation. However, this method can only generate low density plasma and therefore cannot allow full control of film properties. Also, after long runs ~ (1-3) hours, depends on duty cycle the stability of the reactive process is reduced due to increased probability of arc formation. Between 1995 and 1999, a new way of magnetron sputtering called HIPIMS (highly ionized pulse impulse magnetron sputtering) was developed. The main idea of this approach is to apply short ${\sim}(50-100){\mu}s$ high power pulses with a target power densities during the pulse between ~ (1-3) kW/cm2. These high power pulses generate high-density magnetron plasma that can significantly improve and control film properties. From the beginning, HIPIMS method has been applied to reactive sputtering processes for deposition of conductive and nonconductive films. However, commercially available HIPIMS plasma generators have not been able to create a stable, arc-free discharge in most reactive magnetron sputtering processes. HIPIMS plasma generators have been successfully used in reactive sputtering of nitrides for hard coating applications and for Al2O3 films. But until now there has been no HIPIMS data presented on reactive sputtering in cluster tools for semiconductors and MEMs applications. In this presentation, a new method of generating an arc free discharge for reactive HIPIMS using the new Cyprium plasma generator from Zpulser LLC will be introduced. Data (or evidence) will be presented showing that arc formation in reactive HIPIMS can be controlled without applying a positive voltage pulse between high power pulses. Arc-free reactive HIPIMS processes for sputtering AlN, TiO2, TiN and Si3N4 on the Applied Materials ENDURA 200 mm cluster tool will be presented. A direct comparison of the properties of films sputtered with the Advanced Energy Pinnacle Plus + plasma generator and the Zpulser Cyprium plasma generator will be presented.

• 기술사
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• 제10권1호
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• pp.10-14
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• 1977

In accordance with introducing extra high voltage system, system power plants have to be operated in underexcited condition, which causes temperature rise at the stator end portion of turbine generator. This Paper deals with (1) various elements affecting temperature rise and (2) methods of pre-estimating temperature rise.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.959-961
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• 1998

In this paper, we present design rule of high-voltage rectangular generator working in wide band frequency domain. Though power electronics now have voltage ratings up to several kV, it is difficult to design and fabricate high-voltage systems with the power electronic devices alone. So we have combined IGBT with technically designed transformer to get the high-voltage rectangular waveforms. In this work, next two things are the main factors. The first one is design of transformer working low-frequency domain of less than 10Hz. And the second one is adding offset voltage part. As a result, we can get variable frequency high-voltage rectangular waveform and this can be used as a voltage source of sandpaper manufacturing process.

• Transactions on Electrical and Electronic Materials
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• 제7권5호
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• pp.252-256
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• 2006

When a partial discharge takes place at the stator of a generator, the electrical pulse will propagate along the stator bars and the capacitor chains formed by the end part of the stator winds. On the first path, the pulse propagates as a travel wave at slow speed. On the second path, the pulse propagates at quick speed. Based on the data of the experiments on a real 50 MW steam generator, the author has found the pulses can propagate by magnetic field of the stator winding. It was studied that how to locating the partial discharge by signals coming from the different paths, including the features of signals on the two paths at time domain and frequency domain, the measurement frequency rang of the signals, the blind area, the advantage and disadvantage of this method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1574-1575
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• 2011

The application of a pulsed power system is being extended to an environmental and industrial field. The non-destructive gaseous pollutants from industrial plants such as power generation plants and incinerators can be processed by applying high voltage pulses with a fast rising time (a few nanoseconds) and short duration (nano to microseconds) in a pulsed corona discharge reactor. The pulsed plasma generator with a triggered switch has been developed. Its corona current in load can be adjusted by applied voltage and repetition rate. We investigated the performance of the pulsed plasma generator by analyzing the concentration of ozone in small reactor. This paper describes the electrical characteristics of the pulse generator with a voltage of 30 kV at repetition rate of 50 PPS. In addition, we briefly discuss a configuration of the system and initial test results.

• Journal of Power Electronics
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• 제4권3호
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• pp.169-179
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• 2004

This paper presents the steady-state analysis of the three-phase self-excited induction generator (SEIG). The three-phase SEIG with a squirrel cage rotor is driven by a variable-speed prime mover (VSPM) or a constant-speed prime mover (CSPM) such as a wind turbine or a micro gas turbine. Furthermore, a PI closed-loop feedback voltage regulation scheme of the three-phase SEIG driven by a VSPM on the basis of the static VAR compensator (SVC) is designed and evaluated for the stand-alone AC and DC power applications. The simulation and experimental results prove the practical effectiveness of the additional SVC with the PI controller-based feedback loop in terms of its fast responses and high performances