scholarly journals Low-Power Voltage Transformer Smart Frequency Modeling and Output Prediction up to 2.5 kHz, Using Sinc-Response Approach

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4889
Author(s):  
Abbas Ghaderi ◽  
Alessandro Mingotti ◽  
Lorenzo Peretto ◽  
Roberto Tinarelli
Keyword(s):  
Low Power ◽  
Frequency Domain ◽  
Experimental Tests ◽  
Voltage Transformer ◽  
Output Response ◽  
Instrument Transformers ◽  
Disruptive Change ◽  
New Generation

The instrument transformers scenario is moving towards the adoption of a new generation of low-power instrument transformers. This disruptive change also requires that the modeling, characterization, and testing of those devices must be improved. Therefore, this study focuses on a smart approach developed by the authors in a previous study to estimate the output of low-power voltage transformers (LPVT). The approach—which is based on a sort of modeling in the frequency domain (the so-called sinc-response)—allows obtaining the behavior of the LPVT at rated and distorted conditions. Experimental tests performed on off-the-shelf devices confirm the applicability and effectiveness of the proposed approach when estimating the output response of LPVTs.

scholarly journals Smart Characterization of Rogowski Coils by Using a Synthetized Signal

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3359 ◽  
Author(s):  
Alessandro Mingotti ◽  
Lorenzo Peretto ◽  
Roberto Tinarelli
Keyword(s):  
Low Power ◽  
Distribution System ◽  
Network Models ◽  
Experimental Tests ◽  
Current Transformer ◽  
Rogowski Coil ◽  
Sufficient Information ◽  
Instrument Transformers ◽  
Rogowski Coils ◽  
Characterization Procedure

With the spread of new Low-Power Instrument Transformers (LPITs), it is fundamental to provide models and characterization procedures to estimate and even predict the LPITs’ behavior. In fact, distribution system operators and designers of network models are looking for all forms of information which may help the management and the control of power networks. For this purpose, the paper wants to contribute to the scientific community presenting a smart characterization procedure which easily provides sufficient information to predict the output signal of a Low-Power Current Transformer (LPCT), the Rogowski coil. The presented procedure is based on a synthetized signal applied to the Rogowski coil. Afterwards, the validity of the procedure is assessed within the Matlab environment and then by applying it on three off-the-shelf Rogowski coils. Simulations and experimental tests and results involving a variety of distorted signals in the power quality frequency range and by adopting a quite simple measurement setup demonstrated the effectiveness and the capability of the procedure to correctly estimate the output of the tested device.

scholarly journals A phase-locked loop using ESO-based loop filter for grid-connected converter: performance analysis

2021 ◽  
Author(s):  
Baoling Guo ◽  
Seddik Bacha ◽  
Mazen Alamir ◽  
Julien Pouget
Keyword(s):  
Performance Analysis ◽  
Frequency Domain ◽  
Low Frequency ◽  
Experimental Tests ◽  
Frequency Measurement ◽  
Phase Locked Loop ◽  
Frequency Domain Analysis ◽  
Loop Filter ◽  
Control Stability ◽  
Unbalanced Grid

AbstractAn extended state observer (ESO)-based loop filter is designed for the phase-locked loop (PLL) involved in a disturbed grid-connected converter (GcC). This ESO-based design enhances the performances and robustness of the PLL, and, therefore, improves control performances of the disturbed GcCs. Besides, the ESO-based LF can be applied to PLLs with extra filters for abnormal grid conditions. The unbalanced grid is particularly taken into account for the performance analysis. A tuning approach based on the well-designed PI controller is discussed, which results in a fair comparison with conventional PI-type PLLs. The frequency domain properties are quantitatively analysed with respect to the control stability and the noises rejection. The frequency domain analysis and simulation results suggest that the performances of the generated ESO-based controllers are comparable to those of the PI control at low frequency, while have better ability to attenuate high-frequency measurement noises. The phase margin decreases slightly, but remains acceptable. Finally, experimental tests are conducted with a hybrid power hardware-in-the-loop benchmark, in which balanced/unbalanced cases are both explored. The obtained results prove the effectiveness of ESO-based PLLs when applied to the disturbed GcC.

Design of a Force Feedback Chatter Control System

1972 ◽  
Vol 94 (1) ◽  
pp. 5-10 ◽  
Author(s):  
C. Nachtigal
Keyword(s):  
Machine Tool ◽  
Frequency Domain ◽  
Transient Response ◽  
Force Feedback ◽  
Design Procedure ◽  
Experimental Tests ◽  
Work Piece ◽  
Regenerative Chatter ◽  
Chatter Control ◽  
The Stability

The analysis of machine tool chatter from frequency domain considerations is generally accepted as a valid representation of the regenerative chatter phenomenon. However, active control of regenerative chatter is still in its embryonic stage. It was established in reference [2] that a measurement of the cutting force could be effectively used in conjunction with a controller and a tool position servo system to increase the stability of an engine lathe and to improve its transient response. This paper presents the design basis for such a system, including both analytical and experimental considerations. The design procedure stems from a real part stability criterion based on the work by Merritt [1]. Because of the unknown variability in the dynamics of a machine tool system, the controller parameters were chosen to accomodate some mismatch between structure and tool servo dynamics. Experimental tests to determine the stability zone of the controlled machine tool system qualitatively confirmed the analytical design results. The experimental results were consistent in that the transient response tests confirmed the frequency domain stability tests. It was also demonstrated experimentally that the equivalent static stiffness of a flexible work-piece system could be substantially increased.

scholarly journals Noise Optimization Design of Frequency-Domain Air-Core Sensor Based on Capacitor Tuning Technology

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 194
Author(s):  
Shengbao Yu ◽  
Yiming Wei ◽  
Jialin Zhang ◽  
Shilong Wang
Keyword(s):  
Frequency Domain ◽  
Optimization Design ◽  
Signal To Noise Ratio ◽  
Experimental Tests ◽  
Impedance Analysis ◽  
Physical Structure ◽  
Normal Operation ◽  
Amplifier Circuit ◽  
Noise Current ◽  
Air Core

In the semi-aviation frequency-domain electromagnetic measurement, the induction air-core coil and the differential pre-amplifier circuit introduce noise, which affects the sensor and results in receiving weak signals and improving the signal-to-noise ratio of the system. In response to this problem, by analyzing the physical structure of the air-core coil sensor and the mechanism of the amplification circuit, combined with the simulation and experimental tests of voltage noise, current noise, resistance noise and other noise components, analyzed that the thermal noise is the main component of the sensor noise in the system frequency band, but directly removing the matching resistor increases the instability of the circuit, causes the coil to work in an underdamped state, and generates a time domain oscillation at the resonant frequency, source impedance analysis and analysis of differential pre-amplifier circuit in the frequency-domain detection method, abandoning the matching resistance scheme and magnetic flux negative feedback scheme. The matching capacitor is added to make the receiver detect the frequency range in the 1–10 kHz range. In normal operation, the noise level reaches 10 nV level, which not only increases the stability of the circuit, but also reduces the noise of the sensor. It has far-reaching significance for the detection of weak frequency signals.

scholarly journals PMU’s Behavior with Flicker-Generating Voltage Fluctuations: An Experimental Analysis

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3355 ◽  
Author(s):  
Paolo Castello ◽  
Carlo Muscas ◽  
Paolo Pegoraro ◽  
Sara Sulis
Keyword(s):  
Distribution Systems ◽  
Ad Hoc ◽  
Current Trend ◽  
Experimental Tests ◽  
Distribution Networks ◽  
Distribution Grid ◽  
Voltage Fluctuations ◽  
Wide Area Monitoring ◽  
Accuracy Measurement ◽  
New Generation

Phasor measurement units (PMUs), which are the key components of a synchrophasor-based wide area monitoring system (WAMS), were historically conceived for transmission networks. The current trend to extend the benefits of the synchrophasor technology to distribution networks requires the PMU to also provide trustworthy information in the presence of signals that can occur in a typical distribution grid, including the presence of severe power quality (PQ) issues. In this framework, this paper experimentally investigates the performance of PMUs in the presence of one of the most important PQ phenomena, namely the presence of voltage fluctuations that generate the disturbance commonly known as flicker. The experimental tests are based on an ad-hoc high-accuracy measurement setup, where the devices under test are considered as “black boxes” to be characterized in the presence of the relevant signals. Two simple indices are introduced for the comparison among the different tested PMUs. The results of the investigation highlight possible critical situations in the interpretation of the measured values and provide a support for both the design of a new generation of PMUs and the possible development of an updated synchrophasor standard targeted to distribution systems.

Effects of Radial Immersion and Cutting Direction on Chatter Instability in End-Milling

Manufacturing ◽  
2002 ◽  
Author(s):  
Philip V. Bayly ◽  
Brian P. Mann ◽  
Tony L. Schmitz ◽  
David A. Peters ◽  
Gabor Stepan ◽  
...  
Keyword(s):  
Frequency Domain ◽  
End Milling ◽  
Experimental Tests ◽  
Milling Process ◽  
Element Analysis ◽  
Model Stability ◽  
Interrupted Cutting ◽  
Time Marching ◽  
Variance Estimate ◽  
Low Radial Immersion

Low radial immersion end-milling involves intermittent cutting. If the tool is flexible, its motion in both the x- and y-directions affects the chip load and cutting forces, leading to chatter instability under certain conditions. Interrupted cutting complicates stability analysis by imposing sharp periodic variations in the dynamic model. Stability predictions for the 2-DOF model differ significantly from prior 1-DOF models of interrupted cutting. In this paper stability boundaries of the 2-DOF milling process are determined by three techniques and compared: (1) a frequency-domain technique developed by Altintas and Budak (1995); (2) a method based on time finite element analysis; and (3) the statistical variance of periodic 1/tooth samples in a time-marching simulation. Each method has advantages in different situations. The frequency-domain technique is fastest, and is accurate except at very low radial immersions. The temporal FEA method is significantly more efficient than time-marching simulation, and provides accurate stability predictions at small radial immersions. The variance estimate is a robust and versatile measure of stability for experimental tests as well as simulation. Experimental up-milling and down-milling tests, in a simple model with varying cutting directions, agree well with theory.

Experimental tests of a two-layer Monte Carlo-diffusion hybrid model for photon migration in the frequency domain

2001 ◽  
Author(s):  
Gregory W. Faris ◽  
George Alexandrakis ◽  
David R. Busch ◽  
Michael S. Patterson
Keyword(s):  
Monte Carlo ◽  
Frequency Domain ◽  
Hybrid Model ◽  
Experimental Tests ◽  
Photon Migration

Design of the Improved Accompanying Temperature Logger

2014 ◽  
Vol 989-994 ◽  
pp. 3015-3018
Author(s):  
Juan Guo ◽  
Shi Ying Liang ◽  
Zong Tao Yin
Keyword(s):  
Power Consumption ◽  
Energy Conservation ◽  
Low Power ◽  
Communication Protocol ◽  
Reducing Power ◽  
Experimental Tests ◽  
Low Power Consumption ◽  
Temperature Logger ◽  
Ultra Low Power

This paper describes research on some methods of reducing power consumption to reduce the volume accompanying logger. For the requirement of ultra-low power consumption and miniature, the design is described separately from the hardware and software, mainly including temperature detecting module, interface of communication, low current circuit hardware, energy conservation ,arouse from power down state, communication protocol, etc. The experimental tests for device prove that the research can achieve low power requirements.

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