scholarly journals Enhanced Interpolated Dynamic DFT Synchrophasor Estimator Considering Second Harmonic Interferences

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2748 ◽  
Author(s):  
Lei Chen ◽  
Wei Zhao ◽  
Fuping Wang ◽  
Qing Wang ◽  
Songling Huang
Keyword(s):  
Second Harmonic ◽  
Electronic Devices ◽  
Distribution Networks ◽  
Fast Response ◽  
Harmonic Suppression ◽  
Observation Window ◽  
Time Requirements ◽  
Measurement Units ◽  
Ieee Standard ◽  
Better Than

In the future, phasor measurement units are expected to be applied in distribution networks (DNs) for their control and monitoring. Because of the widely used power electronic devices in DNs, harmonics are widely present in a voltage/current signal. Particularly, second harmonics have the most significant uncertainty contributions to synchrophasor estimation, which is especially true when a short cycle observation window is used for a fast response. Based on the interpolated dynamic discrete Fourier transform (IpD 2 FT), this paper introduces an enhanced IpD 2 FT (e-IpD 2 FT) synchrophasor estimator that considers second harmonic interferences. First, the adaptive equivalent filters of the IpD 2 FT are given. Based on these, the optimal frequencies where the IpD 2 FT has the least second harmonic interferences are then searched using an enumeration method, and the e-IpD 2 FT synchrophasor estimator is accordingly proposed. Instantaneous frequency responses and several simulation tests show that the e-IpD 2 FT performs much better than the IpD 2 FT in second harmonic suppression, and can meet the P-class response time requirements and most of the M-class accuracy requirements of the IEEE standard C37.118.1 only over a three-cycle window.

Design of K-band modified hairpin filter with harmonic suppression using GaAs MMIC process

Circuit World ◽  
2019 ◽  
Vol 45 (4) ◽  
pp. 287-291
Author(s):  
Jin Guan ◽  
Min Gong ◽  
Bo Gao ◽  
Yuxi Lu ◽  
Yu Lu
Keyword(s):  
Transmission Lines ◽  
Integrated Circuit ◽  
Second Harmonic ◽  
Simulation Software ◽  
Pass Band ◽  
Harmonic Suppression ◽  
Content Type ◽  
Compact Size ◽  
Better Than ◽  
K Band

Purpose The purpose of this paper is to present a K-band modified hairpin bandpass filter on a planar circuit with harmonic suppression and compact size. Design/methodology/approach The inter-connect transmission lines of conventional hairpin filter are replayed by T-shaped open stub to achieve transmission zero for second harmonic. This filter is simulated and optimized by using electromagnetic simulation software and tested on-chip. Findings This proposed filter shows the return loss of better than −10dB, the insertion loss of better than 2 dB in pass-band and suppression of more than 40 dB at second harmonic. Originality/value The proposed filter can be designed on monolithic microwave integrated circuit, PCB or LTCC and it is useable for microwave and microwave and millimeter-wave systems.

Development of a dual-stage and visual-servo filming robot

2021 ◽  
pp. 095965182199136
Author(s):  
Liang-Chien Liu ◽  
Ping-Han Yang ◽  
Shih-Chi Liao ◽  
Bing-Peng Li ◽  
Fu-Cheng Wang ◽  
...  
Keyword(s):  
Fast Response ◽  
Tracking Performance ◽  
Visual Servo ◽  
Response Characteristics ◽  
Lower Stage ◽  
Upper Stage ◽  
Dual Stage ◽  
Switching Controller ◽  
Similar Evaluation ◽  
Better Than

This article presents the development of a visual-servo filming robot for dolly & truck style camera movement in filming applications. The robot was implemented with a fast-response slider as the upper stage on top of the slow-response tracked robot body as the lower stage, to improve target tracking performance. A new switching controller was developed, which controlled the stages’ motions by balancing and adjusting the weights of vision error and slider’s noncentering error of the upper stage, thus achieving tracking performance better than the traditional master–slave control strategy. The simulations were carried out to evaluate the tracking performance of the model, particularly focusing on evaluating how the dual stage improves the overall response of the model. The similar evaluation was executed experimentally as well. Both results confirm that the fast-response characteristics of the upper stage can compensate the slow dynamics of lower stage, the tracked robot which is inevitably heavy due to its composition.

Second-harmonic suppression in DART-SFIT devices

2014 ◽  
Author(s):  
G. Martin ◽  
E. Chilla ◽  
H. Schmidt ◽  
B. Steiner
Keyword(s):  
Second Harmonic ◽  
Harmonic Suppression

Controllable growth of multilayered XSe2 (X=W and Mo) for nonlinear optical and optoelectronic applications

2D Materials ◽  
2021 ◽  
Author(s):  
Kun Ye ◽  
Lixuan Liu ◽  
Liying Chen ◽  
Wenlong Li ◽  
Bochong Wang ◽  
...  
Keyword(s):  
Large Scale ◽  
Second Harmonic ◽  
Transition Metal Dichalcogenides ◽  
Chemical Vapor ◽  
Fast Response ◽  
Peak Position ◽  
Metal Dichalcogenides ◽  
Controllable Growth ◽  
Optoelectronic Applications ◽  
Layered Transition Metal

Abstract The layered transition metal dichalcogenides (TMDs) exhibit the intriguing physical properties and potential application in novel electronic devices. However, controllable growth of multilayer TMDs remains challenging. Herein, large-scale and high-quality multilayer prototype TMDs of W(Mo)Se2 were synthesized via chemical vapor deposition. For Raman and PL measurements, 2H and 3R multilayer WSe2 crystals displayed significant layer-dependent peak position and intensity feature. Besides, different from the oscillatory relationship of SHG intensity for odd-even layer numbers in 2H-stacked multilayer WSe2, the second harmonic generation intensity of 3R-stacked ones parabolically increased with the thickness due to the absence of inversion symmetry. For device application, photodetectors based on WSe2 with increasing thickness exhibited p-type (bilayer), ambipolar (trilayer), and n-type (4 layers) semiconductor behaviors, respectively. Furthermore, photodetectors based on the as-synthesized 3R-stacked WSe2 flakes displayed an excellent responsivity (R) of 7.8×103 mA/W, high specific detectivity (Da*) of 1.7×1014 Jones, outstanding external quantum efficiency (EQE) of 8.6×102 %, and fast response time (τRise=57 ms and τFall=53 ms) under 532 nm illumination with bias voltage of Vds=5 V. Similar results have also been achieved in multilayer MoSe2 crystals. All these findings indicate great potential of 3R-stacked TMDs in two-dimensional optoelectronic applications.

Compact LowPass Filter with Wide StopBand Using Non-Uniform Microstrip Resonant Cells

2012 ◽  
Vol 263-266 ◽  
pp. 15-19
Author(s):  
Yan Liang ◽  
Xiao Ming Wu ◽  
Bi Hua Tang ◽  
Yong Le Wu
Keyword(s):  
Microstrip Line ◽  
Photonic Bandgap ◽  
Impedance Matching ◽  
Stop Band ◽  
Cutoff Frequency ◽  
Harmonic Suppression ◽  
Lowpass Filter ◽  
Measurement Results ◽  
Better Than

In this paper, a novel compact microstrip lowpass filter is designed. The proposed filter which is etched on the 50 Ω microstrip line consists of four non-uniform 1-D microstrip photonic bandgap (PBG) cells with different cutoff frequency.. The demonstration lowpass filter with 2.2 GHz cutoff frequency is designed, fabricated and measured. The measurement results show that the band rejection effect is better than -20 dB from 2.8 GHz to 10 GHz, the insertion is less than 2 dB, and the length of filter is 5.6 cm long. Compared with the conventional filter, the proposed filter has smaller size. Meanwhile, it overcomes the problems of narrow stop-band and low harmonic suppression. Furthermore, the impedance matching is not need to be considered. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

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