• 전력전자학회논문지
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• 제13권1호
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• pp.9-14
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• 2008

멀티레벨 인버터 시스템에 낮은 스위칭 주파수가 사용되면, 이들 멀티레벨 인버터 시스템은 큰 값의 저 주파수 고조파 성분을 발생한다. 일반적으로 이러한 문제를 해결하기 위해 LC필터가 인버터 시스템의 출력단에 사용되었다. 그러나 LC필터를 사용한 경우 제동저항의 사용에 의한 전압강하가 발생하고, 제동저항의 전력손실로 인해 시스템의 효율이 감소하는 문제를 야기하게 된다. 본 논문에서는 낮은 스위칭 주파수를 갖는 3상 NPC 3레벨 인버터를 위한 출력 필터 설계방법을 제안하였다. 그리고 제안된 필터 시스템의 효율을 분석하였고, 제안된 시스템의 효과는 시뮬레이션과 실험결과를 통하여 입증하였다.

• Journal of Power Electronics
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• 제19권6호
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• pp.1380-1392
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• 2019

Input filters are very important to matrix converters (MCs). They are used to improve grid side current waveform quality and to reduce the input voltage distortion supplied to the grid side. Due to the effects of the input filter and the output power, the grid side power factor (PF) is not at unity when the input power factor angle is zero. In this paper, the displacement angle between the grid side phase current and the phase voltage affected by the input filter parameters and output power is analyzed. Based on this, a new grid side PF unity compensation method implemented in the indirect space vector pulse width modulation (ISVPWM) method is presented, which has a larger compensation angle than the traditional compensation method, showing a higher grid side PF at unity in a wide output power range. Simulation and experimental results verify that the analysis of the displacement angle between the grid side phase current and the phase voltage affected by the input filter and output power is right and that the proposed compensation method has a better grid side PF at unity.

• 전력전자학회논문지
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• 제11권4호
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• pp.313-320
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• 2006

본 논문에서는 단상 NPC 멀티레벨 인버터의 출력단 고조파 저감을 위한 LC 트랩 필터의 설계 방법을 제시하였고, 출력전압 THD와 출력전류 고조파 FFT 분석을 수행하였다. 제시된 LC 트랩 필터는 일반적인 LCR 필터와 종속 접속된 구조를 가지며, 스위칭 주파수에 동조되었다. 인버터 시스템은 고전력 응용에 적합한 NPC 멀티레벨 인버터를 사용하였으며, 제어기는 DSP(TMS320C31)을 사용하여 구성하였다. 제안된 시스템의 효용성은 시뮬레이션과 실험 결과를 통하여 증명하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.748-751
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• 2000

in this paper the design procedure of three phase voltage source inverter output filter is described. The 'd' axis transfer function of the filter output voltage to the load current is described with the capacitor value and the system time constant including the controller. This means that the relation between the filter capacitor value and the system time constant is given as the closed form. By using the above closed form the capacitor value can be calculated with the system time constant is given as the closed,. form the capacitor value can be calculated with the system time constant which can be implemented practically not using the try and error method. And as the effect of the load is connected.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.161-167
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• 1993

This paper presents robustness properties of the Kalman Filter ad the associated LQG/LTR method for linear time-invariant systems having delays in both the state and output. A circle condition relating to the return difference matrix associated with the Kalman filter is derived. Using this circle condition, it is shown that the Kalman filter guarantees(1/2, .inf.) gain margin and .+-.60.deg. phase margin, which are the same as those for nondelay systems. However, it is shown that, even for minimum phase plants, the LQG/LTR method can not recover the target loop transfer function. Instead, an upper bound on the recovery error is obtained using an upper bound of the solution of the Kalman filter Riccati equations. Finally, some dual properties between output-delated system and input-delayed systems are exploited.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.337-340
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• 2004

To develop the highly sensitive Magneto-Impedance sensor, the amorphous ribbon was micro-processed to meander type sensor pattern and the filter circuit was constructed with this pattern. Its external magnetic field dependence of impedance and the output properties of the filter circuit were investigated. The impedance of the pattern had a peak value at the magnetic field of 10 Oe and its changing ratio was about 280%. The impedance change per unit magnetic field was about 36%, in which the output with high sensitivity and linearity could be obtained. The output sensitivity was about 7%/Oe at bias field of 6 Oe..

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1077-1079
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• 2000

In this paper. the design procedure of the inverter output filter is described. The transfer function of the filter output voltage to the load current is described with the capacitor value and the system time constant including the controller. This means that the relation between the filter capacitor value and the system time constant is given as the closed form. By using the above closed form. the capacitor value can be calculated with the system time constant which can be implemented practically not using the try and error method. And as the effect of the load current to the voltage distortion can be calculated from the closed form, it can be verified how much the voltage distortion is effected when the nonlinear load is connected.

• 대한전자공학회논문지
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• 제20권4호
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• pp.1-9
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• 1983

MRAS 초안주 출력 오차 모델(MRAS hyperstable output-error model)을 이용한 적응 순환 필터(adaptive recursive filter)의 설계상 가장 어려운 점은 오차 완화 필터 (error-smoothing filter)의 설계이다. 본 논문에서는 적응 순환 필터의 대표적 알고리즘인 HARF(hyperstable adaptive recursive filter) 알고리즘을 적절히 변형시킴으로써 오차 완화 필터를 제거시킬 수 있고, 동시에 수산 속도도 바른 알고리즘을 얻을 수 있음을 보였다.

• Journal of Power Electronics
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• 제13권6호
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• pp.1058-1069
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• 2013

This paper proposes and designs a new output filter called an LCFL filter for application to three phase three wire shunt active power filters (SAPF). This LCFL filter is derived from a traditional LCL filter by replacing its capacitor with a C-type filter, and then constructing an L-C-type Filter-L (LCFL) topology. The LCFL filter can provide better switching ripple attenuation capability than traditional passive damped LCL filters. The LC branch series resonant frequency of the LCFL filter is set at the switching frequency, which can bypass most of the switching harmonic current generated by a SAPF converter. As a result, the power losses in the damping resistor of the LCFL filter can be reduced when compared to traditional passive damped LCL filters. The principle and parameter design of the LCFL filter are presented in this paper, as well as a comparison to traditional passive damped LCL filters. Simulation and experimental results are presented to validate the theoretical analyses and effectiveness of the LCFL filter.

• 전기학회논문지
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• 제56권2호
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• pp.383-388
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• 2007

This paper considers a low-order dynamic output feedback controller design problem. Since the proposed control law inherently has a low-pass filter property, it can alleviate the mal-effects of the sensor noise without additional filter designs. Frequency domain analysis shows the characteristics of the proposed control law against measurement noise. The effectiveness of the proposed control law is illustrated by numerical simulations with a rotary inverted pendulum and a convey-crane. Using only one integrator the proposed control law has the advantage to the stabilization problem with sensor noise as well as it can successfully replace the measurements of derivative terms in a state feedback control law.