• 전력전자학회논문지
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• 제9권6호
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• pp.584-591
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• 2004

기존의 아날로그 점호각 제어방법은 op-amp, 저항 및 커패시터 등을 사용하였기 때문에 아날로그 회로의 특성상 온도와 소자의 경년변화에 따라 파라메타 값이 변동하며 전원전압의 노이즈에 민감하게 반응하는 단점이 있었다. 따라서 본 논문에서는 디지털 사이리스터 점호회로를 이용하여 기존의 아날로그 점호회로 장점인 선형특성, 그리고 전원전압 노이즈 온도 및 갱년변화에 의한 수동소자의 변동에 강인한 특징을 갖는다. 또한 디지털 시스템의 장점인 연산기능을 이용하여 전원전압의 불평형 발생시 디지털 시스템의 특징인 연산기능을 이용하여 전원전압의 불평형을 검지하고 보상알고리즘을 도입하여 언제나 리플이 없는 출력전압을 만들어내어 사이리스터 전력변환 시스템의 안정적인 운전이 가능하게 할 수 있는 장점이 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1061-1063
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• 2001

This paper proposes a new power conditioning system for the SMES composed of a thyristor PWM converter with a resonant commutation circuit. The operation of the proposed system and the dynamic interaction between SMES and the power system is analyzed by a theoretical approach with equivalent circuits and verified by computer simulations with EMTP, considering a typical 154kV power system. The proposed system can provide a solution for the power factor regulation and harmonic level reduction in the ac terminal with low-cost system configuration.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.565-568
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• 2003

The conventional analog-based firing circuit can be implemented by comparing a linearly decreasing periodic sawtooth waveform synchronized to the ac line, with a voltage corresponding to the desired converter delay angle. This circuit requires a large number of components (resistance and capacitor) and careful adjustment of the synchronization circuity In this paper a novel firing circuit is proposed for thyristor switch is elements. The proposed circuit is implemented on the basis of the analog cosine method using FPGA and microprocessor.

• 전력전자학회논문지
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• 제27권5호
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• pp.397-401
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• 2022

The construction of the ITER tokamak machine is ongoing at a 77% process rate to achieve the first plasma in 2025. The 18 sets of power supply systems comprising 400 MVA thyristor AC/DC converters for the superconducting magnets supplied by Korea (KO) are being installed with other systems, such as PF converters (China), DC busbars (Russia), and cooling water systems (India), in two buildings (Europe). The system interfaces have been defined during the design stage, and the systems have been manufactured. However, during the on-site installation work, several installation and integration issues emerged due to the manufacturing tolerance and design mistakes. To continue the installation and testing, the engineers of each system resolved the interface issues, planned the commissioning, and integrated the test plan. This paper describes the on-site installation status and issues and the commissioning plan of KO AC/DC converters.

• 전기학회논문지
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• 제61권6호
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• pp.833-837
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• 2012

In HVDC System, the rapid voltage breakdown between anodes and cathodes during valve firing causes radio interference in HVDC converter station. These voltage breakdown causes steep current pulse and inject current in system. As a result, harmonic frequencies are generated from valve, switchyard. In this paper, theoretical background of radio interference in HVDC converter is discussed and its reduction method for radio interference is proposed.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권4호
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• pp.194-202
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• 1999

Various ways of designing heat sink are available for commercial high power converters and among them, the method of air cooling is the most popular and practical method than any other ones. In this paper, a practical method of cooling high power converter, which includes a method of reducing noise and vibration caused by the fan and a method of estimating the gap and contact resistances existing between the thyristor and heat sink, is presented. Finally, the heat transfer analysis and implementation methods of heat sink for high power converter is presented.

• 조명전기설비학회논문지
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• 제24권12호
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• pp.91-99
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• 2010

HVDC converter station consists of a number of equipment such as converter transformer, ac filter, thyristor valve and so on. They can be acoustic noise sources. In this paper, we analyzed the simulation results of the outdoor acoustic noise for HVDC converter station. It shows that maximum noise level in boundary of HVDC converter station exceeds regulation value. The main factors in generating maximum noise level are ac filter and converter transformer. Then we applied some soundproof countermeasures in HVDC converter station. Shielding wall is enough to reduce transformer noise level but not enough to reduce ac filter noise level. In case of ac filter, soundproof building is effective in satisfying noise level regulation in boundary of HVDC converter station. In addition, we also studied effects of season, soundproof woods, ground.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.491-495
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• 2001

Compare with diode or thyristor bridge AC/DC converter, the 3 phase PWM converter has some merits of low THD and unit power factor. So, in many critical application like as UPS, using PWM converter is the trends. 3 phase PWM converter had been studied widely already. But analytical design procedure can not found from publication for hardware design and controller design. So, in this paper, 3 phase PWM converter analysis review was given. And from the DC analysis result, parameter design was done. From the AC model, the voltage controller and current controller was designed. The gain of controllers was calculated by analytical method.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 춘계학술대회 논문집
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• pp.322-327
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• 1999

In most railway vehicle applications, a single phase AC/DC converter is used greatly and is essential equipment for Korea High Speed Train. A diode bridge rectifier and a phase-controlled thyristor bridge rectifier generate harmonics in power system. Nowadays, power factor and harmonics become major issue in electrical equipment for railway vehicle. Many researchers have been trying to improve the power factor and ac-side harmonics. Therefore the PWM converter is used to operate at unity Power factor and to reduce ac-side current harmonics. This paper describes the circuit for AC/DC PWM converter of Korea High Speed Train and proposes control algorithm to realize the sinusolidal input current waveform and the effective unity power factor. The validity of the proposed control method is verified through the experimental result.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.782-785
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• 2005

This article introduces technique to reduce harmonic by using the $5^{th}$ and $7^{th}$ harmonic tune filter and line reactor in the comparison to the technique of intervening firing method at the pulse of the 6-pulse phase-controlled converter in every 1/6 period. The design of the technique introduced in this article is to reduce the harmonic distortion of the current and the voltage resulted from three-phase thyristor phase-controlled converter. The waveform obtained from the experiment was analyzed on the spectrum of the current, voltage and the total harmonic distortion. The double firing method causes zero vectors of output voltage and input current. Designing the mechanism of the converter based on the idea of Park Vector Theory, the number of harmonic distortion in the intervening firing method were compared to those in normal firing method.