• Journal of Power Electronics
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• 제11권6호
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• pp.904-913
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• 2011

Previous publications regarding the design and specifications of input filters for STATCOMs usually deal with the input filter only, and seldom pay any attention to the influence of the input filters on the performance of the STATCOM systems. A detailed analysis of the influences of input filters on the stability of STATCOM systems and the corresponding design considerations are presented in this paper. Three types of input filters, L filters, LC filters, and LCL filters, are examined separately. The influences of the parameters of input filters on system stability are investigated through frequency domain methods. With direct current control taken as the major control strategy for the STATCOMs, the different situations when adopting different current detection points are covered in this analysis. A comparison between LC filters and LCL filters is also presented with optimized filter parameters. Based on the analysis, the phase margin, as one of the design considerations for the different types of input filters under different current detection schemes, is discussed. This leads to filter parameters that are different than those of the traditional design. Hardware experimental results verify the validity of the above analysis and design.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.178-179
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• 2017

Input filter is an essential component in a practical matrix converter (MC) system to generate the sinusoidal input currents. However, the input filter causes a displacement angle between the input current of MC and the source current. In this paper, we investigate the input filter design for MCs by considering the displacement angles of the input current and the input voltage to guarantee high input power factor (IPF) operation as well as low input current harmonic contents. Simulation results are provided to validate the input filter design with near unity input power factor and low total harmonic distortion (THD) of the input current.

• 한국융합학회논문지
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• 제4권4호
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• pp.41-48
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• 2013

Observer design for system with unknown input was carried out. First, Kalman filter was considered to estimate system state with White noise. With the results of Kalman filter design, state observer, controller properties, including controllability and observability, and the Kalman filter structure and algorithm were also studied. Kalman filter algorithm was applied to Position and velocity measurement based on Kalman filter with white noise, and it was constructed and achieved by programming based on Matlab programming. Finally, observer for system with unknown input was constructed with the help of Gershgorin's disc theorem. With the designed observer, system states was constructed and applied to system with unknown input. By simulation results, estimation performance was verified. In this project, state feedback control theory, observer theory and relevant design procedure, as well as Kalman filter design were understood and used in practical application.

• 대한전기학회논문지
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• 제45권1호
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• pp.30-41
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• 1996

Current Source(CS) PWM converter is appropriate for the magnet power supply system which requests high power and high precision current control. Input and output filters should be installed to eliminate the current or voltage harmonics caused by the PWM switching for the CS PWM converter. But the input/output filters limit the output DC current range and may destroy the system with filter resonance, and make the system equation more complicated. In this paper, systematic and simple filter design method which considers not only the harmonic attenuation but also the total system good transfer function characteristics in the dc filter. The simulated and experimental results verify the proposed theory. (author). refs., figs., tabs.

• 전력전자학회논문지
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• 제7권5호
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• pp.490-498
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• 2002

본 논문에서는 전압형 PWM 컨버터의 교류 입력측 LCL 필터의 설계기법을 제안한다 기존의 전압형 PWM 컨버터에서 전원계통으로 흘러 들어가는 스위칭 고조파전류를 억제하기 위해 교류 입력측에 LCL 필터를 설치하는 것은 매우 경제적이고 효과적인 방법이다 필터 커패시터로 스위칭 고조파전류를 흡수하며 공진을 억제하기 위해 수동 댐핑 저항을 이용한다 UPS용의 LCL 필터 구조 PWM 컨버터의 설계예시를 보였으며 제안한 설계기법의 타당성을 입증하기 위해 PSIM을 이용한 시뮬레이션을 행하였다.

• 조명전기설비학회논문지
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• 제12권1호
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• pp.35-44
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• 1998

본 연구에서는 전류스트레스 및 필터소자의 용량저감을 고려한 다이오드 정류기의 입력LC필터 설계법을 기술하였다. 입력교류전류의 제3고조파 성분에 대하여 무한한 임피던스를 갖도록 LC병렬 공진회로와 출력측 직류콘덴서로 구성된 새로운 필터를 단위법(Per Unit)에 의해 설계하였다. 제안된 LC필터를 다이오드정류기에 적용하여 정상상태에서 실험한 결과, 입력교류전류의 제3고조파성분을 8.8〔%〕로 감소시켰으며, 입력역률은 종전의 표준형의 입력역률이 0.76인데 비하여 0.913으로 개선시켰다. 또한 필터소지자의 전압.전류용량감소와 함께, 설계된 입력LC필터는 다이오드 정류기계통에 악영향을 미치지 않았으며, 따라서 종래의 표준형 LC필터에 의한 방법과 비교하여 제안된 방법이 83.5〔%〕의 저용량의 필터로도 고역률의 정류가 가능함을 입증하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.307-310
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• 2002

A design for the input filter and the output filter of a single-phase UPS system is proposed. And also, this paper describes a reduction of the DC voltage ripple of a single-phase UPS. The input power of proposed UPS fluctuates with twice frequency of the utility source, which causes DC voltage fluctuation. The reduction of the DC voltage fluctuation requires a large DC link capacitor. The proposed method uses a LC series resonant filter paralleled with a conventional smoothing capacitor. The effectiveness of the proposed method was confirmed by simulation results.

• 대한의용생체공학회:의공학회지
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• 제13권2호
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• pp.107-114
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• 1992

An adaptive filter for noise cancellation of ECG Is proposed. An adaptive noise canceller using the least mean squares algorithm Is used to reduce unwanted noise. An adaptive filter for nolse cancella lion minimizes the mean-square error between a primary input and a reference input. A primary input is the noisy ECG, and a reference input is a noise that Is correlated in some way with the noise in the primary input or a signal that is correlated only with ECG in the primary input.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.259-261
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• 1996

In this paper, active input filter for power factor correction(PFC) circuit employing ripple arrent and voltage cancellation is proposed to reduce filter's size and cost, and to make filter design easy. Switching ripple current and voltage can be sensed through the secondary windings of filter inductor. Single stage passive filter can achieve high order filter characteristics by using active ripple current and voltage cancellation technique. Conventional high order passive filter and its problems are suggested. Analysis of active filter and design procedure are detailed. Simulation result is presented to verify high order filter characteristics of proposed scheme.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 전문대학교육위원
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• pp.132-135
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• 2005

A design for the input filter and the output filter of a single-phase uninterruptible power supply (UPS) system is proposed. A filter design example is presented. And also, this dissertation describes a reduction of the DC voltage ripple of a single-phase UPS. The input power of proposed UPS fluctuates with twice frequency of the utility source, which causes DC voltage fluctuation. The reduction of the DC voltage fluctuation requires a large DC link capacitor. The proposed method uses a LC series resonant filter paralleled with a conventional smoothing capacitor. The effectiveness of the proposed method was confirmed by simulation results.