On the Long-Period Accuracy Behavior of Inductive and Low-Power Instrument Transformers

The accuracy evaluation of instrument transformers is always a key task when proper control and management of the power network is required. In particular, accuracy becomes a critical aspect when the grid or the instrumentation itself is operating at conditions different from the rated ones. However, before focusing on the above non-rated conditions, it is important to fully understand the instrument transformer behavior at rated conditions. To this end, this work analyzed the accuracy behavior of legacy, inductive, and low-power voltage transformers over long periods of time. The aim was to find patterns and correlations that may be of help during the modelling or the output prediction of voltage transformers. From the results, the main differences between low-power and inductive voltage transformers were pointed out and described in detail.

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Are Inductive Current Transformers Performance Really Affected by Actual Distorted Network Conditions? An Experimental Case Study

Sensors ◽

10.3390/s20030927 ◽

2020 ◽

Vol 20 (3) ◽

pp. 927 ◽

Cited By ~ 3

Author(s):

Alessandro Mingotti ◽

Lorenzo Peretto ◽

Lorenzo Bartolomei ◽

Diego Cavaliere ◽

Roberto Tinarelli

Keyword(s):

Operating Conditions ◽

Accuracy Evaluation ◽

Current Transformers ◽

Need To Evaluate ◽

Instrument Transformers ◽

Instrument Transformer ◽

Secondary Result ◽

Error Index ◽

Accuracy Performance

The aim of this work is to assess whether actual distorted conditions of the network are really affecting the accuracy of inductive current transformers. The study started from the need to evaluate the accuracy performance of inductive current transformers in off-nominal conditions, and to improve the related standards. In fact, standards do not provide a uniform set of distorted waveforms to be applied on inductive or low-power instrument transformers. Moreover, there is no agreement yet, among the experts, about how to evaluate the uncertainty of the instrument transformer when the operating conditions are different from the rated ones. To this purpose, the authors collected currents from the power network and injected them into two off-the-shelf current transformers. Then, their accuracy performances have been evaluated by means of the well-known composite error index and an approximated version of it. The obtained results show that under realistic non-rated conditions of the network, the tested transformers show a very good behavior considering their nonlinear nature, arising the question in the title. A secondary result is that the use of the composite error should be more and more supported by the standards, considering its effectiveness in the accuracy evaluation of instrument transformers for measuring purposes.

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Toward the Standardization of Limits to Offset and Noise in Electronic Instrument Transformers

Sensors ◽

10.3390/s20144061 ◽

2020 ◽

Vol 20 (14) ◽

pp. 4061

Author(s):

Alessandro Mingotti ◽

Lorenzo Peretto ◽

Roberto Tinarelli

Keyword(s):

Low Power ◽

Mathematical Approach ◽

Electronic Instrument ◽

Critical Aspect ◽

Correct Operation ◽

Ratio Error ◽

Instrument Transformers

The scenario of instrument transformers has radically changed from the introduction of the Low-Power version, both passive and active. The latter type, typically referred to as Electronic Instrument Transformers (EITs), has no dedicated standard within the IEC 61869 series yet. To this purpose, in the authors’ opinion, it is worth understanding how the limits of typical disturbances affecting EITs should be standardized. In particular, after a brief review of the standards, the work presented a mathematical approach to determine the sources of signal disturbances influence, which affect the rms value, on the ratio error. From the results, we discussed that the emergence of disturbances generated within the EIT is a critical aspect to be studied with data of typical off-the-shelf devices. Therefore, to guarantee a correct operation of the devices, a proper standardization of the sources of disturbance should be provided.

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Optimised calibration programmes for comparators for instrument transformers

tm - Technisches Messen ◽

10.1515/teme-2020-0086 ◽

2021 ◽

Vol 88 (2) ◽

pp. 122-131

Author(s):

Christian Mester

Keyword(s):

Experimental Study ◽

Operating Principle ◽

Device Under Test ◽

Operating Range ◽

Ratio Error ◽

Phase Displacement ◽

Instrument Transformers ◽

Instrument Transformer ◽

Method Of Measurement

Abstract Traditionally, instrument transformers are calibrated using bridges. By definition, bridges use the null method of measurement. The traditional calibration programme for instrument transformer bridges characterise namely this null measurement. Many new commercial comparators for instrument transformer use a very different method. They sample the secondary signals of reference and device under test (dut) transformer independently. Based on the samples, magnitude and phase of both signals are determined. Ratio error and phase displacement are calculated. Consequently, the significance of their calibration using the traditional calibration programme is limited. Moreover, the operating range of modern comparators is much larger than that of bridges. The additional versatility cannot be used without an adapted calibration programme. This article analyses the calibration programmes for both technologies. An experimental study confirms both the suitability of the new calibration programme and the need to chose the calibration programme depending on the technology of the device to be calibrated. The conclusion is very general and applies to all measurement problems where an operating principle is replaced by another – when changing the operating principle, it is important to check the calibration programme and adapt it if necessary.

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Design of R3TOS based reliable low power network on chip

2017 Seventh International Conference on Emerging Security Technologies (EST) ◽

10.1109/est.2017.8090423 ◽

2017 ◽

Author(s):

N Poornima ◽

Seetharaman Gopalakrishnan ◽

Tughrul Arsalan ◽

T. N. Prabakar ◽

M. Santhi

Keyword(s):

Low Power ◽

Network On Chip ◽

Power Network ◽

On Chip

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Remotely Accessible, Low Power Network Attached Storage Device

2018 Second International Conference on Inventive Communication and Computational Technologies (ICICCT) ◽

10.1109/icicct.2018.8473164 ◽

2018 ◽

Cited By ~ 1

Author(s):

Anirudh Lanka ◽

Arjun Gargeyas

Keyword(s):

Low Power ◽

Storage Device ◽

Power Network ◽

Network Attached Storage

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The Downside of Software-Defined Networking in Wireless Network

UKH Journal of Science and Engineering ◽

10.25079/ukhjse.v4n2y2020.pp147-156 ◽

2020 ◽

Vol 4 (2) ◽

pp. 147-156

Author(s):

Zahraa Saleh ◽

Qahhar Qadir

Keyword(s):

Low Power ◽

Communication Networks ◽

Data Extraction ◽

Software Defined Networking ◽

Network Control ◽

Control Logic ◽

High Loss ◽

Traffic Volumes ◽

High Level ◽

Control And Management

Mobile traffic volumes have grown exponentially because of the increase in services and applications. Traditional networks are complex to manage because the forwarding, control, and management planes are all bundled together and, thus, administrators are supposed to deploy high-level policies, as each vendor has its own configuration methods. Software-Defined Networking (SDN) is considered the future paradigm of communication networks. It decouples control logic from its underlying hardware, thereby promoting logically centralized network control and making the network more programmable and easy to configure. Low-power wireless technologies are moving toward a multitenant and multiapplication Internet of Things (IoT), which requires an architecture with scalable, reliable, and configured solutions. However, employing an SDN-based centralized architecture in the environment of a low-power wireless IoT network introduces significant challenges, such as difficult-to-control traffic, unreliable links, network contention, and high associated overheads that can significantly affect the performance of the network. This paper is a contribution toward a performance evaluation for the use of SDN in wireless networking by evaluating the latency, packet drop ratio (PDR), data extraction rate (DER), and overheads. The results show that SDN adds a high percentage of overheads to the network, which is about 43% of the 57% user packets, and the DER drops when the number of mesh nodes are increased, in addition to the high loss that was observed for packets that traveled over more hops.

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