Double Tuned Active Filter 기능을 갖는 Single Tuned Active Filter

김찬기,양병모 전력전자학회 2004 전력전자학회 논문지 Vol.9 No.6

This paper deals with the hybrid active filter which can reduce the 11th/13th harmonics in AC network by using the single tuned filter. Since the proposed algorithm uses the detuning compensation capability of the filter, the output voltage of the proposed active power filter is changed according to the capacitance of capacitors, magnitude of harmonic current, resonance frequency and control mode. In this paper, the control characteristics and the design of hybrid active filter is investigated. A new hybrid active filter with new algorithm, which is an active filter with single tuned filter instead of double tuned filter, is proposed. 본 논문은 Single Tuned Filter를 사용하여 11차와 13차 고조파를 동시에 제거하는 Hybrid 능동필터를 제안하였다. 제안된 Hybrid 능동필터는 Hybrid 능동필터의 Detuning 보상능력을 이용한 것으로, 하나의 필터를 이용하여 2개 이상의 고조파를 제거할 수 Topology를 보여주고 있다. 본 논문에서 다루는 Hybrid 능동필터는 Detuning 보상능력을 이용한 것이기 때문에 인버터 출력전압을 최적으로 설계하는 것이 필수적이다. 본 논문은 수동필터 부분의 커패시터 용량과 HVDC 시스템에서 발생되는 고조파 전류의 크기 그리고 수동필터의 공진주파수와 제어모드에 따라 인버터 출력전압이 변화함을 확인하였고, 이에 따른 최적의 인버터 전압을 구하였다.

Design of IIR Structure Active Mufflers using Stabilized Filter Algorithms

Dong-Jun Ahn(안동준),Hyun-Do Nam(남현도) 한국산학기술학회 2019 한국산학기술학회논문지 Vol.20 No.3

능동 머플러는 자동차 머플러의 배기소음을 저감하기 위하여 능동 소음 제어 기법을 적용하여 구현된다. 기존의 보편적인 Filtered_x LMS 알고리즘은 음향 궤환이 존재할 경우 제어필터의 차수가 매우 커지고 수렴성이 악화되는 문제가 있다. 이를 보완할 수 있는 Recursive LMS 알고리즘은 적응필터의 적응과정에서 쉽게 발산할 수 있어 적용이 제한되어 왔다. 본 논문에서는 수렴 성능과 계산량 부담이 개선되도록 1차 경로와 2차 경로 전달함수의 구조를 IIR 필터로 설계하였으며 IIR 필터 구조의 단점인 안정성 확보를 위해 안정화 필터 알고리즘을 적용하였다. 안정화 필터 알고리즘은 적응과정 중에 음향 궤환에 해당하는 전달함수의 극점이 발산하는 것을 방지하기 위하여 극점을 단위원 내부로 끌어 당기는 역할을 수행한다. 이러한 방법으로 능동 머플러 시스템의 계산량 절감과 수렴성능을 향상시킬 수 있다. 제안한 시스템의 유용성을 보이기 위하여 가변 환경인 디젤 엔진의 배기음향을 대상으로 기존의 Filtered_x LMS 알고리즘과 제안한 시스템과의 성능을 비교하여 그 우수성을 보였으며, 계산량은 절반 이하, 수렴 특성은 4배 이상의 성능을 보였다. Active muffler is implemented by applying active noise control technique to reduce exhaust noise of automobile muffler. Conventional Filtered_x LMS algorithm has a problem that the degree of control filter becomes very large and convergence deteriorates when acoustic feedback is present. The recursive LMS algorithm can compensate for this problem because it can be easily diverted in the adaptive filter adaptation process. In this paper, the structure of the primary path and the secondary path transfer function is designed as the IIR filter to improve the convergence performance and the computational burden, and the stabilization filter algorithm is applied to secure stability which is a disadvantage of the IIR filter structure. The stabilization filter algorithm plays a role of pulling the pole into the unit circle to prevent the pole of the transfer function corresponding to the acoustic feedback from diverging during the adaptation process. In this way, the computational burden of the active muffler system and the convergence performance can be improved. In order to show the usefulness of the proposed system, we compared the performance of the proposed Filtered_x LMS algorithm with the performance of the proposed system for the exhaust sound of a diesel engine, which is a variable environment. Compared to conventional algorithm, proposed algorithm"s computational burden is less than half, and convergence performances are more than 4 times.

Active Damping for Wind Power Systems with LCL Filters Using a DFT

June-Seok Lee,Hae-Gwang Jeong,Kyo-Beum Lee 전력전자학회 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.2

This paper proposes a simple active damping algorithm for small-scale wind power systems with an LCL filter. Compared to an L filter or an LC filter, an LCL filter can decrease the harmonics induced by low switching frequencies and produce a satisfactory grid-side current using a comparatively low inductance. Additional active damping of the filter resonance is necessary when an LCL filter is used. This paper introduces an active damping method using a Discrete Fourier Transform (DFT) filter to improve performance without additional sensors or complexity. Experimental results are shown to verify the validity of the proposed algorithm as an active damping method.

능동전력필터의 기준신호발생을 위한개선된 적응예측필터의 성능 분석

배병열,백승택,한병문 전력전자학회 2004 전력전자학회 논문지 Vol.9 No.6

The performance of active power filter depends on the inverter characteristic, the control method, and the accuracy of reference signal generator. The accuracy of reference signal generator is the most critical item to determine the performance of active power filter. This paper introduces a novel reference signal generator composed of improved adaptive predictive filter. The performance of proposed reference signal generator was verified by means of simulation with MATLAB. The application feasibility was evaluated by building and experimenting a single-phase active power filter based on the proposed reference generator, which was implemented in the DSP(digital signal processor) TMS320C31. Both simulation and experimental results confirm that the proposed reference signal generator can be utilized for the active power filter. 능동전력필터의 성능은 인버터의 특성, 제어 방법, 그리고 기준신호발생기의 정확도에 좌우된다. 이중에서 기준신호발생기의 정확도는 능동전력필터의 성능을 결정짓는 가장 중요한 요소이다. 본 논문은 개선된 적응예측필터로 구성한 새로운 기준신호발생기에 대해 소개하고 그 성능을 MATLAB을 이용한 시뮬레이션으로 검증하였다. 그리고 실제 하드웨어의 적용타당성을 평가하기 위해 개선된 기준신호발생기로 구성한 알고리즘을 TMS320C31 DSP(digital signal processor)에 구현하고 이 기준신호발생기를 기반으로 하는 단상능동전력필터의 축소모형을 제작하여 실험을 실시하였다. 시뮬레이션과 실험결과로 제안하는 기준신호발생기가 위상지연이 없는 기준신호를 추출하여 능동전력필터에 활용가능하며 그 성능도 대단히 우수함을 알 수 있었다.

필터 종류에 따른 Semi-volatile 화합물 이행 특성

김정열,신창호 한국연초학회 1997 한국연초학회지 Vol.19 No.2

Semivolatile components in mainstream smoke of cigarette attached the different type filter were analysed. Based on the main peak of GC profile, benzene, toluene, acetic acid, limonene, acetamide, pyridine, nicotine, phenol, pyrrole, and furfuryl alcohol were identified. The amount delivered of semivolatile components by each filter was evaluated with the ratio of areas of sample vs area% of ISTD. By comparing dual and triple filter to mono filter, the delivery amounts were 52% benzene, 62% toluene and 74% benzene, 84% toluene, respectively. The delivery amount of limonene which was known of tobacco taste component, were 52%, and 93% by dual and triple filter, respectively. Also, delivery amounts of acetic acid which was one of acidic compounds in smoke, were 86% and 83% by dual and triple filter, respectively. When adding the same amount of active carbon, the amounts delivered of vapour phase such as benzene and toluene by dual filter were lower than that of triple filter. But the delivery amounts of acetic acid and phenol by dual filter were higher than that of triple filter. This results assume that the pH of active carbon in filter affect to the adsorption or absorption of triacetin during filter making process.

능동 인덕터를 이용한 주파수 가변형 대역통과 필터 설계

이석진(Lee, Seok-Jin),최석우(Choi, Seok-Woo) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.7

최근 이동통신 시장의 급속한 증가에 따라 단말기 설계는 다표준 방식으로 발전하고 있다. 본 논문에서는 다표준 이동통신 시스템에 적용할 수 있는 주파수 가변형 능동 RC 대역통과 필터를 능동 인덕터를 사용하여 설계하 였다. 기존의 대역통과 필터 설계법에서는 저지대역의 감쇠 특성과 통과대역의 주파수 선택도를 향상시키기 위하여 필터의 차수를 높게 하거나 극점 Q 를 증가시키는 설계법을 사용한다. 본 논문에서는 극점 Q 가 높은 능동 인덕터로 대역통과 필터를 설계하여 주파수 특성이 향상되었다. 또한 설계된 대역통과 필터는 튜닝 회로를 이용하여 필터의 중 심주파수와 이득을 간단히 조절할 수 있도록 제안하였다. 설계된 능동 RC 대역통과 필터 특성은 TSMC 0.18㎛ 공정 파라미터를 이용하여 해석하였다. 시뮬레이션 결과, Q=20.5를 갖는 능동 인덕터를 이용한 필터는 1.86GHz 중심주파 수에서 90MHz의 대역폭을 갖고, 튜닝 회로의 커패시터 값으로 중심주파수를 1.86∼2.38GHz 범위까지 튜닝이 가능하 여 다표준 무선통신 시스템에 적용할 수 있다. The fast-growing market in wireless communications has led to the development of multi-standard mobile terminals. In this paper, a frequency-tunable active RC bandpass filter for multi-standards wireless communication system is designed using an active inductor. The conventional bandpass filter design methods employ the high order filter or high quality factor Q to improve the stopband attenuation characteristics and frequency selectivity of the passband. The proposed bandpass filter based on the high Q active inductor has an improved frequency characteristics. The center frequency and gain of the designed bandpass filter is tuned by employing the tuning circuit. We have performed the simulation using TSMC 0.18㎛ process parameter to analyze the characteristics of the designed active RC bandpass filter. The bandpass filter with Q=20.5 has 90MHz half power bandwidth at the center frequency of 1.86GHz. Moreover, the center frequency of the proposed bandpass filter can be tuned between 1.86∼2.38GHz for the multi-standards wireless communication system using the capacitor of the tuning circuit.

하이브리드 능동전력필터의 전력품질 개선을 위한 Coordinate Transformation 기법에 대한 성능 비교

손진근,박현수,이현재,박훈양 대한전기학회 2022 전기학회논문지 P Vol.71 No.1

In this paper, the performances of Coordinate transformation method for harmonic and reactive power compensation of hybrid active power filters were compared and analyzed. Recently, as the spread of power electronic devices is expanding, the occurrence of harmonics in the system is increasing, and the harmonics have a bad effect on the system and electrical equipment. As a measure against such harmonics, the parallel resonance problem of passive power filters among filters can be solved, and a hybrid active power filter with a small compensation capacity of the active power filter can be considered. However, In order to control the hybrid active power filter to the required power factor, it is necessary to control it through fast tracking even when the load changes. Therefore, in this paper, the performance was analyzed by applying the p-q theory method and the compensation current control method using d-q respectively to the hybrid active power filter. As a result of comparing and analyzing the effects through simulation, it was confirmed that using the p-q theory method quickly followed the target value with a relatively small error even with a variable load than using the d-q method.

Three-Phase Hybrid Shunt Filters for Power Quality Improvement

G. Bhuvaneswari,Manjula G.Nair 전력전자학회 2007 JOURNAL OF POWER ELECTRONICS Vol.7 No.3

Active power filters can be cost-effective for use in practical systems with the insertion of a few passive elements in shunt or series configuration. The resulting hybrid filters can be designed to provide dominant lower order harmonic elimination and reactive power support by the passive elements so that the burden on the active filter counterpart is reduced. In this paper, the rate reduction in the shunt active filter is estimated when it is connected in parallel with suitable passive tuned harmonic filters. The active filtering system is based on an appropriate control scheme. The simulation and the experimental results of the shunt active filter, along with the estimated value of reduction in rating, show that the hybrid shunt filtering system is quite effective in compensating for the harmonics and reactive power, in addition to being cost-effective.

직ㆍ병렬 능동 전력필터 시스템을 이용한 불평형 전원전압 보상

姜旻衡(Min-Hyung Kang),金榮石(Young-Seok Kim) 대한전기학회 2007 전기학회논문지 Vol.56 No.4

This paper suggests of a 3-phase 3-wire unified active power filter. The system is composed of a series active power filter and a parallel active power filter. The proposed series active power filter compensating unbalance source voltage and current harmonics of the parallel active power filter improves power factor. The proposed algorithm which improves for power factor and harmonic reduction are calculated by the performance function, and which compensates for the unbalanced source voltage is calculated based on the symmetrical component analysis. We composed a combined system of the series active power filter and parallel active power filter to confirm a validity of the proposed control methods. The effectiveness of the proposed algorithm is confirmed by the experiments.

복합형 전력필터 설계에 관한 연구

송의호 國立 昌原大學校 産業技術硏究所 2002 産技硏論文集 Vol.16 No.-

A new hybrid power filter using variable capacitor banks is presented to overcome the high cost problem of the active or the other hybrid active filters. The proposed hybrid active filter which consists of tuned(5th and 7th harmonics) LC passive filters, power factor improvement(PFI) capacitor bank, and active filter compensates power factor as well as harmonic currents. Since most of harmonic currents are filtered by the passive filter and most of reactive power is compensated by the PFI capacitor bank, the power rating of active filter can be minimized, resulting in cost minimization of the proposed hybrid active filter. A 400kVA hybrid active filter system is implemented and tested using 1MVA thyristor rectfier load to verify the operation and performance.