Topic
Tuned filter
About: Tuned filter is a research topic. Over the lifetime, 305 publications have been published within this topic receiving 2585 citations.
Papers published on a yearly basis
1 / 2
Papers
TL;DR: In this paper, a new tunable optical filter has been developed which rejects a narrow wavelength interval ( 90%). This filter will be useful in optics, in spectroscopy, and for laser applications.
Abstract: A new tunable optical filter has been developed which rejects a narrow wavelength interval ( 90%). This filter will be useful in optics, in spectroscopy, and for laser applications. The active element of the filter is a crystalline colloidal array of polystyrene spheres. The rejected wavelengths are Bragg diffracted from this ordered array. For a particular sphere concentration and scattering from a particular set of lattice planes, tunability can be achieved by the altering of the angle between the filter and incident light beam. Bragg diffraction and light rejection of these filters are monitored by transmission measurements. The utility of this filter for spectroscopic measurements is demonstrated for Raman spectroscopy. Raman measurements are shown for polypropylene, a highly scattering material with numerous low-frequency modes. The filter selectively attenuates the elastically scattered light and allows the low frequency peaks to be observed. Use of this wavelength rejection filter to reject the Rayleigh scattered light simplifies the instrumentation, decreases the cost, and increases the sensitivity of Raman spectral measurements. This filter also has the potential to replace dispersive elements such as gratings and prisms in a variety of spectroscopic and optical applications.
209 citations
TL;DR: In this paper, the authors investigate the filter topology selection issue and present their research results on the effectiveness and costs of various filter topologies for harmonic mitigation, they show that the association of three single-tuned filters is a very appropriate solution for most typical harmonic problems.
Abstract: Passive filters have been a very effective solution for power system harmonic mitigation. These filters have several topologies that give different frequency response characteristics. The current industry practice is to combine filters of different topologies to achieve a certain harmonic filtering goal. However, there is a lack of information on how to select different filter topologies. This decision is based on the experience of present filter designers. The goal of this paper is to investigate the filter topology selection issue. It presents our research results on the effectiveness and costs of various filter topologies for harmonic mitigation. The research results show that the association of three single-tuned filters is a very appropriate solution for most typical harmonic problems.
168 citations
TL;DR: In this paper, a maximally flat 10.7-MHz fourth-order bandpass filter with an on-chip automatic tuning system is presented, and the power consumption of the system is 220 mW.
Abstract: A maximally flat 10.7-MHz fourth-order bandpass filter with an on-chip automatic tuning system is presented. The signal-to-in-band integrated noise ratio (SNR) of the automatically tuned filter is around 68 dB. The third intermodulation distortion (IM3) is lower than -40 dB for a two-tone input signal of 3.2 V peak to peak (V/sub p-p/). The complete system operates with supply voltages of +or-2.5 V. The power consumption of the system is 220 mW. All this has been achieved due to the use of a low-distortion transconductor, the development of a high-frequency CMOS resistor, and the realization of an advanced on-chip automatic tuning system for both frequency and bandwidth control. The chip has been fabricated in a standard 1.5- mu m n-well CMOS process. >
165 citations
TL;DR: Through the experiments, the validity of CMV and DM harmonics suppression by the hybrid filter in the three-phase inverter is verified and the calculation-control active CM filter is proved to be the best in the optional schemes.
Abstract: In the motor systems driven by sinusoidal pulse width modulation (SPWM) three-phase inverters, the peaks of common-mode (CM) voltage are so high that it will cause many negative effects. In this paper, a hybrid filter is presented to reduce the CM voltage (CMV) and the differential-mode (DM) harmonics in a three-phase inverter with carrier peak position modulation (CPPM). Because the use of CPPM strategy in the inverter can ensure that the output CMV will be only two levels in any condition, the simple active CM filter (composed of a half-bridge circuit) in the hybrid filter can effectively suppress the output CMV and CM current. The passive filter in the hybrid filter consists of an added single tuned filter and the original DM low-pass filter. The single tuned filter is designed to lower the DM harmonics, which are aggravated by the CPPM strategy in the carrier frequency band. Through the experiments, the validity of CMV and DM harmonics suppression by the hybrid filter in the three-phase inverter is verified and the calculation-control active CM filter is proved to be the best in the optional schemes.
79 citations
TL;DR: In this paper, a new method for planning single-tuned passive harmonic filters to control harmonic voltage distortion throughout a power system is presented, where the probabilistic characteristics of the harmonic source currents and network harmonic impedances in the filter planning are taken into account.
Abstract: This paper presents a new method for planning single-tuned passive harmonic filters to control harmonic voltage distortion throughout a power system. In the problem, the probabilistic characteristics of the harmonic source currents and network harmonic impedances in the filter planning are taken into account. The objective is to minimize the total filter installation cost, while the harmonic voltage limits and filter component constraints are satisfied with predetermined confidence levels. To obtain the optimal size of each filter component of the planning problem, the proposed procedure is first to find the candidate filter buses based on the sensitivity analysis. Next, the formulated probability-constrained problem is transformed into a deterministic nonlinear programming problem and is solved by a genetic-algorithm-based optimizer. The proposed solution procedure is tested with an actual distribution network and is verified by the conventional deterministic approach and by the Monte Carlo simulation. Numerical experiences show that the proposed method yields favorable results compared with the other two approaches.
78 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 5 |
| 2020 | 11 |
| 2019 | 9 |
| 2018 | 15 |
| 2017 | 16 |
| 2016 | 16 |