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Voltage-controlled filter

About: Voltage-controlled filter is a research topic. Over the lifetime, 5514 publications have been published within this topic receiving 70872 citations. The topic is also known as: VCF.


Papers
More filters
Journal ArticleDOI
Fei Li1, Xing Zhang1, Zhu Hong1, Haoyuan Li1, Changzhou Yu1 
TL;DR: In this paper, a new kind of high-order filter, named LCL - LC filter, is presented, and a parameter design method on the base of the resonant frequency characteristics of the filter is also proposed.
Abstract: In order to further cut down the cost of filter for grid-connected pulsewidth modulation (PWM) converter under the more and more stringent grid code, a new kind of high-order filter, named LCL - LC filter, is presented in this paper. The resonant frequency characteristics of the filter are analyzed, and a parameter design method on the base of the characteristics is also proposed in the paper. The proposed parameter design method can easily make full use of the existing research results about the traditional LCL filter parameter design. And then a parameter robustness analysis method based on four-dimensional graphics is proposed to analyze parameter robustness of the presented filter. Compared with the traditional one, the proposed analysis method can analyze the filter performance under variations of several parameters at a time without any iteration. The comparative analysis and discussion considering the LCL filter, the trap filter, and the LCL - LC filter, are presented and verified through the experiments on a 5 kW grid-connected converter prototype. Experiment results demonstrate the accuracy of theoretical analysis and prove that the presented filter has a better performance than two others.

89 citations

Proceedings ArticleDOI
20 Jun 1993
TL;DR: In this paper, a modified synchronous reference frame (SRF) based controller for the series active filter allows injection of a controlled percentage of the higher harmonic load currents into the supply, in compliance with the IEEE 519 harmonic current standards, thereby reducing the passive filter terminal voltage THD.
Abstract: A simple and cost-effective solution to reduce the passive filter terminal voltage total harmonic distortion (THD) is outlined. A modified synchronous reference frame (SRF) based controller for the series active filter allows injection of a controlled percentage of the higher harmonic load currents into the supply, in compliance with the IEEE 519 harmonic current standards, thereby reducing the passive filter terminal voltage THD. This implementation retains all the desirable features of the original SRF controlled hybrid series active filter system. It reduces the rating and size of the passive filter system and allows the use of simpler passive filter system structures such as only a simple high pass passive filter or a simple power factor correction capacitor as the passive filter system. Simulation and experimental results are used to establish the functionality and performance of the SRF controller and the modified SRF controller for the hybrid series active filter system. >

88 citations

Patent
04 Mar 1991
TL;DR: In this paper, an analog-to-digital converter includes a delta-sigma modulator (10), having the output of the modulator filtered by a digital filter section.
Abstract: An analog-to-digital converter includes a delta-sigma modulator (10), having the output thereof filtered by a digital filter section. The digital filter section includes a first fixed decimation filter (12) followed by a variable decimation filter section (14) and an output low-pass filter section (16), having a fixed decimation ratio. The fixed variable decimation filter section (14) includes a single FIR filter (24) that has data processed therethrough with different sampling rates. A recursive controller (26) receives an external configuration input to determine the number of passes through the filter (24) that are required to provide the desired decimation ratio.

88 citations

Patent
06 Apr 1994
TL;DR: In this paper, a cross-coupled switched capacitor circuit was used to reduce the size of the capacitors in a biquad switched capacitor filter, which reduced the capacitance by a factor of two.
Abstract: A biquad switched capacitor filter is preferably utilized as the output filter in a sigma delta digital-to-analog converter. The switched capacitor filter uses a cross-coupled switched capacitor circuit which delivers charge to the capacitors on both phases of the clock. As a result, the sizes of the capacitors can be reduced by a factor of two, while delivering the same charge as a single sampling circuit. By using the cross-coupled switching circuit everywhere in the filter, the sensitivity to capacitor mismatches is substantially reduced. The clock phases applied to the stages of the filter are alternated so that there is a one clock cycle delay around each loop containing two filter stages, thereby insuring the stability of the filter.

88 citations

Journal ArticleDOI
TL;DR: In this article, the Harris HSP 43168 Finite-Impulse Response (FIR) filter bank was used to detect weak signals in a background of noise and the search for narrow-band radio emissions from extraterrestrial civilizations.
Abstract: We have designed and constructed an agile 8-channel digital filter bank on a 9U VME board that operates at a maximum clock rate of 36 MHz. A set of these boards have been employed to create 100-200 MHz, 50-100 channel spectrometers. Our applications involve detection of weak signals in a background of noise--pulsar radio astronomy and the search for narrow-band radio emissions from extraterrestrial civilizations. The agility factors include total bandwidth, spacing of filter channels, selection of filter response and choice of output data format (voltage or detected power). The input is a complex analog voltage centered on zero frequency which is passed to the board via coaxial ports on the front panel. The computational kernels on this board are Harris HSP 43168 Finite Impulse Response (FIR) filter devices. We can also operate the board in a 16-channel output mode. The 2-4 bit format digital output is presented to a custom backplane. Along with our development we have written a suite of simulation software tasks both to determine the sensitivity loss and non-linear gain response that result from quantization and to optimize filter responses.

88 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20239
202229
20201
20188
2017150
2016199