scholarly journals Active Power Measurement Based on Multiwavelet Transforms

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Xiao-Bing Zhang ◽  
Yun-Hui Li ◽  
Xiao-Meng Cui
Keyword(s):  
Time Domain ◽  
Fourier Transforms ◽  
Active Power ◽  
New Method ◽  
Power Measurement ◽  
The Time Domain ◽  
Better Than

This paper discusses a new method for calculating active power in the multiwavelet domain. When the voltage and current waveforms are analyzed using multiwavelet, the active power can be calculated by simply adding the products of the multiwavelet coefficients without having to reconstruct the signals back to the time domain first and then using the traditional integration. From the simulation result, we can see that the results using multiwavelet are better than the ones using wavelet and Fourier Transforms no matter which prefilter is used.

scholarly journals Total Radiated Power Measurement in an Uncalibrated Reverberation Chamber

2019 ◽  
Vol 69 (5) ◽  
pp. 427-430
Author(s):  
Deepshikha Gururani ◽  
Harish S. Rawat ◽  
Satya K. Dubey ◽  
V.N. Ojha
Keyword(s):  
Quality Factor ◽  
Time Domain ◽  
Indoor Environment ◽  
Real Life ◽  
Power Measurement ◽  
Shielding Effectiveness ◽  
Reverberation Chamber ◽  
Radiated Power ◽  
Reverberation Chambers ◽  
The Time Domain

With the increased use of wireless communication in recent years, the use of reverberation chamber (RC) has increased to a great extent. Reverberation chambers have been eminently used for EMC testing and shielding effectiveness. The environment it provides is very similar to the reverberant surroundings that antenna undergoes in real life use. An experiment to measure total radiated power of antenna, antenna efficiency and quality factor of chamber in indoor environment is proposed. This will make the measurement very simple and inexpensive as designing and calibration of chamber will not be needed. In this paper, we have used three different techniques to compare total radiated power, quality factor, Rician K factor and efficiency of a patch antenna measured in indoor environment with RC data. The three method used include plate stirring method and two time domain methods. The time domain methods use modulated pulse and Gaussian pulse respectively for the measurement. The antenna and chamber parameters are measured in the real time and the data matched well with the RC data for different techniques.

scholarly journals Multiple Spatiotemporal Characteristics-Based Zonal Voltage Control for High Penetrated PVs in Active Distribution Networks

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 249 ◽  
Author(s):  
Chuanliang Xiao ◽  
Lei Sun ◽  
Ming Ding
Keyword(s):  
Time Domain ◽  
Reactive Power ◽  
Voltage Control ◽  
Distribution Networks ◽  
Spatial Domain ◽  
Active Power ◽  
Short Term ◽  
Control Scheme ◽  
The Time Domain ◽  
Active Distribution Networks

The penetration of photovoltaic (PV) outputs brings great challenges to optimal operation of active distribution networks (ADNs), especially leading to more serious overvoltage problems. This study proposes a zonal voltage control scheme based on multiple spatiotemporal characteristics for highly penetrated PVs in ADNs. In the spatial domain, a community detection algorithm using a reactive/ active power quality function was introduced to partition an ADN into sub-networks. In the time domain, short-term zonal scheduling (SZS) with 1 h granularity was drawn up based on a cluster. The objective was to minimize the supported reactive power and the curtailed active power in reactive and active power sub-networks. Additionally, a real-time zonal voltage control scheme (RZVC) with 1 min granularity was proposed to correct the SZS rapidly by choosing and controlling the key PV inverter to regulate the supported reactive power and the curtailed active power of the inverters to prevent the overvoltage in each sub-network. With the time domain cooperation, the proposed method could achieve economic control and avoid overvoltage caused by errors in the forecast data of the PVs. For the spatial domain, zonal scheduling and zonal voltage control were carried out in each cluster, and the short-term scheduling and voltage controlling problem of the ADN could then be decomposed into several sub-problems. This could simplify the optimization and control which can reduce the computing time. Finally, an actual 10kV, 103-node network in Zhejiang Province of China is employed to verify the effectiveness and feasibility of the proposed approach.

Active Power Measurements - An Overview and a Comparison of DSP Algorithms by Noncoherent Sampling

2011 ◽  
Vol 18 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Milos Sedlacek ◽  
Zdenek Stoudek
Keyword(s):  
Time Domain ◽  
Additive Noise ◽  
Digital Signal ◽  
Power Estimation ◽  
Active Power ◽  
Test Signal ◽  
Additional Information ◽  
Measurement Results ◽  
The Time Domain ◽  
Power Measurements

Active Power Measurements - An Overview and a Comparison of DSP Algorithms by Noncoherent Sampling This paper presents an overview of algorithms for one-phase active power estimation using digital signal processing in the time domain and in the frequency domain, and compares the properties of these algorithms for a sinusoidal test signal. The comparison involves not only algorithms that have already been published, but also a new algorithm. Additional information concerning some known algorithms is also included. We present the results of computer simulations in MATLAB and measurement results gained by means of computer plug-in boards, both multiplexed and using simultaneous signal sampling. The use of new cosine windows with a recently published iterative algorithm is also included, and the influence of additive noise in the test signal is evaluated.

An open-source full 3D electromagnetic modeler for 1D VTI media in Python: empymod

Geophysics ◽  
2017 ◽  
Vol 82 (6) ◽  
pp. WB9-WB19 ◽  
Author(s):  
Dieter Werthmüller
Keyword(s):  
Fourier Transform ◽  
Time Domain ◽  
Fourier Transforms ◽  
Transverse Isotropy ◽  
Hankel Transform ◽  
Transform Methods ◽  
Electromagnetic Responses ◽  
The Time Domain ◽  
Ground Penetrating ◽  
Vertical Transverse Isotropy

The Python-code empymod computes the 3D electromagnetic field in a layered earth with vertical transverse isotropy by combining and extending two earlier presented algorithms in this journal. The bottleneck in frequency- and time-domain calculations of electromagnetic responses derived in the wavenumber-frequency domain is the transformations from the wavenumber to the space domain and from the frequency to the time domain, the so-called Hankel and Fourier transforms. Three different Hankel transform methods (quadrature, quadrature-with-extrapolation [QWE], and filters) and four different Fourier transform methods (fast Fourier transform [FFT], FFTLog, QWE, and filters) are included in empymod, which allows us to compare these different methods in terms of speed and precision. The best transform in terms of speed and precision depends on the modeled frequencies. Published digital filters for the Hankel transform are very fast and precise for frequencies in the range of controlled-source electromagnetic data, but they fail in the frequency range of ground-penetrating radar. Conventional quadrature, on the other hand, is in comparison very slow but can model any frequency. Examples comparing empymod with analytical solutions and with existing electromagnetic modelers illustrate the capabilities of empymod.

scholarly journals Blind Speech Separation in Convolutive Mixtures Using Negentropy Maximization

2010 ◽  
Author(s):  
Vuong Hoang Nam ◽  
Nguyen Quoc Trung ◽  
Tran Hoai Linh
Keyword(s):  
Time Domain ◽  
Main Idea ◽  
New Method ◽  
Speech Separation ◽  
Simulation Experiments ◽  
Convolutive Mixtures ◽  
The Time Domain ◽  
Innovation Processes

This paper proposes a new method to address the  problem  of  blind  speech  separation  in  convolutive mixtures in the time domain. The main idea is extract the  innovation  processes  of  speech  sources  by  nonGaussianity  maximization  and  then  artificially  color them  by  re-coloration  filters.  Some  simulation experiments of the 2x2 case are presented to illustrate the proposed approach.

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