Phasor Measurement Improvement Using Digital Filter in a Smart Grid

2021 ◽  
pp. 100-117
Author(s):  
Abderrahmane Ouadi ◽  
Abdelkader Zitouni
Keyword(s):  
Smart Grid ◽  
Digital Filter ◽  
Renewable Energy Sources ◽  
Point Of View ◽  
Optimization Approach ◽  
Operation Condition ◽  
Pass Filter ◽  
Phasor Measurement ◽  
Low Pass ◽  
Computational Requirement

During a transient operation condition of power smart grid, line current may include unwanted components that may cause unnecessary tripping of protection system. The disturbance mainly appears in a form of harmonics and sub-harmonics. In this case of signal waveforms including harmonics, the low pass filter may be used. However, this type of filter does not provide the ability to reject sub-harmonics. This chapter presents the digital filtering design issue based on optimization approach for removing sub-harmonics and hence improving the measurement. The first point of view is to reach an unified accurate phasor measurement algorithm that is immune to nearly all disturbances (sub-harmonics) in power grid including FACT devices and renewable energy sources, simultaneously with required speed of convergence. The second point focuses on reducing the computational requirement and algorithm complexity through designing recursive digital filter with reduced order.

Scattering and information

1970 ◽  
Vol 268 (1185) ◽  
pp. 177-200 ◽  
Keyword(s):  
Structural Information ◽  
Speckle Noise ◽  
Quantitative Information ◽  
Sampling Interval ◽  
Point Of View ◽  
Partial Coherence ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Scattering Volume

The paper discusses some aspects of scattering of electromagnetic radiation in inhomogeneous media from the point of view of information theory. A theory is developed, based on a concrete model of a typical scattering experiment, which takes into account the finiteness of the scattering volume and the coherence characteristics of the radiation; as a conclusion, the speckle noise which is superimposed over the signal is brought into evidence. More exactly, it is shown that the spurious oscillations are due to the non-vanishing character of the convolution square of the inhomogeneity distribution function at the point of truncation in the primary space. Subsequently, the structural information of scattering experiments is examined and the finite logoncontent determined. The sampling interval is established and the resolution achievable in scattering measurements is deduced; also the means by which it can be improved are examined. An analysis of the quantitative information obtainable is pursued and the desirability of filtering is suggested. Finally, the way in which the partial coherence effectively acts as a low-pass filter is studied.

Construction of a High-Pass Digital Filter from a Low-Pass Digital Filter

1994 ◽  
Vol 10 (4) ◽  
pp. 374-381 ◽  
Author(s):  
Stephen D. Murphy ◽  
D. Gordon E. Robertson
Keyword(s):  
Digital Filter ◽  
Low Frequency ◽  
Frequency Noise ◽  
Band Pass Filter ◽  
Low Frequency Noise ◽  
Pass Filter ◽  
Low Pass Filter ◽  
High Pass Filter ◽  
Low Pass ◽  
High Pass

To remove low-frequency noise from data such as DC-bias from electromyo-grams (EMGs) or drift from force transducers, a high-pass filter was constructed from a low-pass filter of known characteristics. A summary of the necessary steps required to transform the low-pass digital were developed. Contaminated EMG and force platform data were used to test the filter. The high-pass filter successfully removed the low-frequency noise from the EMG signals. The high-pass filter was then cascaded with the low-pass filter to produce a band-pass filter to enable simultaneous high- and low-frequency noise reduction.

Trajectory tracking compensation for teleoperation with transmission delays

Robotica ◽  
2011 ◽  
Vol 29 (6) ◽  
pp. 863-871 ◽  
Author(s):  
Lingyan Hu ◽  
Xiaoping P. Liu ◽  
Guoping Liu ◽  
Shaoping Xu
Keyword(s):  
Trajectory Tracking ◽  
Time Delays ◽  
Point Of View ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Transmission Delays ◽  
Additional Signal ◽  
Wave Variables ◽  
Reference Velocity ◽  
Low Pass

SUMMARYThe proper transmission of wave variables rather than power variables in teleoperation with time delays ensures system passivity – rendering the entire system stable, but the introduction of wave variables leads to distortion between the velocities/positions of the master and slave, and the performance deteriorates significantly with the increase of time delays. This paper presents a new compensating scheme implemented at the slave side to remove or cancel partially the distortion. The system passivity can still be maintained by tuning a properly designed low-pass filter. Compared with previous work, the main contribution of this work exists in two points: first, it is the actual velocity/trajectory of the slave rather than the reference velocity/trajectory of the slave that tracks the master one, so the quality of tracking is better and converges faster; second, the proposed compensator does not require any additional signal from the master side, minimizing the amount of data transmitted over the channel, which is very important from the practical point of view. The simulation and experiment results show that the velocity (or trajectory) tracking is significantly improved under the condition of stability, and the force presented to the user is close to the environment one, meaning a high degree of system transparency is achieved.

The Design of Digital Filter Based on DSP Builder

2014 ◽  
Vol 602-605 ◽  
pp. 2641-2644
Author(s):  
Xiao Li Hu ◽  
Li Ding ◽  
Zhi Gang Zhang
Keyword(s):  
Digital Filter ◽  
Hardware Description Language ◽  
Description Language ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Paper Model ◽  
Dsp Builder ◽  
Quartus Ii ◽  
Low Pass ◽  
Hardware Description

This paper model digital FIR low-pass by using the Toolbox of the DSP Builder in MATLAB and convert to VHDL hardware description language, compile and simulation through QUARTUS II software automatically, download and verified by EPF10K20RC208-4.The design combine MATLAB software with FPGA hardware organic ally and completes the transplant of the FIR low-pass filter.

scholarly journals Damping techniques for grid-connected converters with LCL filter: an overview

2021 ◽  
Vol 42 (2) ◽  
pp. 227
Author(s):  
Arthur de Abreu Romão ◽  
Newton Da Silva
Keyword(s):  
Renewable Energy Sources ◽  
Design Procedure ◽  
Voltage Source ◽  
Third Order ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Resonant Behavior ◽  
Low Pass ◽  
Grid Connected Converters ◽  
Low Pass Filters

Distributed generation systems, based on renewable energy sources, are typically connected to the main grid by a voltage-source inverter with a low-pass filter. The need for improved efficiency led to the use of third order low-pass filters, such as the LCL configuration, which has resonant behavior. In order to meet energy quality requirements and ensure the systems stability it is necessary to suppress the LCL filters resonance through damping techniques. Therefore, this paper presents an overview of some damping strategies found in literature and its design procedure, applied to a simulated single-phase grid-tied inverter. The comparison of each presented damping methodology characteristics is described, with analysis of advantages and drawbacks for each case.

scholarly journals Application of Empirical Wavelet Transform in Digital Image Watermarking

2020 ◽  
Vol 37 (5) ◽  
pp. 839-845
Author(s):  
Mohammad Keivani ◽  
Amir Mahdi Sazdar ◽  
Jalil Mazloum ◽  
Akram Esvand Rahmani
Keyword(s):  
Wavelet Transform ◽  
Image Watermarking ◽  
Low Cost ◽  
Original Data ◽  
Point Of View ◽  
Security Requirements ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Empirical Wavelet Transform ◽  
Low Pass

Nowadays, rapid growth of the Internet and digital multimedia technologies make it possible to duplicate data without any loss of quality and at a very low cost. In this regard, manipulation of documents will easily be accomplished by applying digital art and without the copyright owner's permission. To deal with situation, more diverse security requirements are introduced every day. Watermarking is considered as one of the methods used for achieving this purpose. Watermarking is focused on inserting a subtle signal between the host media data somehow it does not change the original data, but they can be extracted if necessary. They are also used as a claim for ownership of the digital effect. Various methods have been presented for watermarking so far. These methods have been developed to overcome the weaknesses of previous methods. Empirical wavelet transform is taken into account as a new method for hiding and extracting military digital images with respect to alpha composition. As such, it is resistant to noise, low pass filter and compression. Analytical studies showed that this method is more efficient than other methods from quantitative and qualitative point of view.

Application of Wavelet Digital Filter of Fourier Transform Profilometry in 3-D Measurement

2004 ◽  
Vol 471-472 ◽  
pp. 654-657
Author(s):  
Yun Shan Wang ◽  
S. Fu ◽  
Jin Quan Xu ◽  
Can Lin Zhou ◽  
S.C. Si ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Wavelet Transform ◽  
Digital Filter ◽  
High Frequency ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Fourier Transform Profilometry ◽  
Low Pass ◽  
Phase Demodulation

Fourier transform profilometry in 3-D measurement based on wavelet digital filter is presented in this paper. Before phase demodulation, original modulated grating image is handled with wavelet transform in order to remove the background components and high frequency. This method resolves spectrum overlapping at some extent and reduces the requirement of low-pass filter.

A View of Recursive Digital Filter Design Methods

1976 ◽  
Vol 13 (4) ◽  
pp. 371-379
Author(s):  
S. M. Bozic
Keyword(s):  
Digital Filter ◽  
Filter Design ◽  
Simple Design ◽  
Simple Manner ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Digital Filter Design ◽  
Recursive Digital Filter ◽  
Low Pass ◽  
Z Transformation

The object of this paper is to examine and explain in a simple manner some of the inherent properties of the bilinear z-transformation as used in the recursive low-pass filter design. It also compares it with the standard z-transformation and illustrates some finer points on a simple design example.

Research on Digital Filter Design for Orthogonal Decomposition Algorithm Applied in Coriolis Flow Meters

2013 ◽  
Vol 475-476 ◽  
pp. 161-166
Author(s):  
Wu Liu ◽  
Guo Qing Ding ◽  
Xin Chen
Keyword(s):  
Digital Filter ◽  
Filter Design ◽  
Notch Filter ◽  
Orthogonal Decomposition ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Flow Meters ◽  
Digital Filter Design ◽  
Low Pass ◽  
Coriolis Flow Meters

Coriolis flow meters are used in measuring flow amount of natural gas and oil due to the good performance and high precision. Orthogonal decomposition algorithm is the most efficient algorithm with the highest precision in processing the digital signals of Coriolis flow meters, and digital filter design is vital important in the algorithm. In this paper we introduce a digital filter system combining the self-adaptive lattice notch filter and low pass filter embedded with Hanning Window or Kaiser Window, we also discussed the parameters selection and adjusting method deeply and systematically. For self-adaptive lattice notch filter, we calculate the key feedback parameter ρ based on bandwidth BW, leading the relative error of frequency calculated within 0.01%. For low pass digital filter, we adjust the filter order through monitoring the sine feature of the orthogonal component that has passed the low pass filter, and the relative errors of phase difference are within 0.1%. We also demonstrate the feasibility of this system through simulation under MATALAB system and calculating experiments data of Coriolis flow meter.

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