1,543 Results Found

In real-world scenarios, deviations in the frequency response of instrumentation transformers can lead to distorted harmonic measurements, highlighting the critical role harmonic measurement plays in assessing power quality. The blind channel equaliz...

The accuracy of instrument transformers (ITs) is vital for the accurate measurement of electrical quantities. However, their performance is influenced by various factors during operation, including environmental conditions such as temperature, pressu...

Voltage and current measurements in high-voltage substations are fundamental for stable operation. Conventional instrument transformers (ITs) face challenges in gas-insulated switchgears (GISs), such as size, weight, accuracy limitations, and behavio...

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...

Current and voltage instrument transformers are essential elements of the power system. They work like transformers but do not transmit power. Their task is to accurately transform currents or voltages during system operation, which are then used for...

In this review article, ideas for the development of measuring methods and setups to test inductive instrument transformer accuracy for the transformation of distorted current or voltage are analyzed. This article proposes limiting values for ratio e...

Power grids are a combined system where the electrical energy produced by the power plants is transmitted to consumers. This forms a specific interdependence where the recipients have a significant impact on the power quality. Therefore, the nonlinea...

Nowadays, different Industry 4.0 technologies have been implemented into diverse industries. However, these implementations are not standardized across similar industries and countries. Consequently, companies are actively looking for assessment inst...

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 with...

Internal arc testing is still a controversial topic in the instrument transformer world. The main reason for that is the fact that even a fully successful test guarantees only a certain degree of transformer safety. Furthermore, the test does not cov...

This paper serves as a comprehensive “starter pack” for electrical diagnostic methods for power transformers. It offers a thorough review of electrical diagnostic techniques, detailing the required instrumentation and highlighting key res...

Instrument transformers are largely used to measure voltages and currents in public electricity networks. Their performance is essential for Power Quality measurements. Tests and procedures to estimate the effect of single influence factors are perfo...

The integration of renewable energy sources on a large scale in the electrical energy distribution systems, as well as the widespread of non-linear loads, has led to a significant increase in power quality (PQ) disturbances. For this reason, PQ monit...

Instrument transformers (ITs) play a key role in electrical power systems, facilitating the accurate monitoring and measurement of electrical quantities. They are essential for measurement, protection, and metering in transmission and distribution gr...

Objectives: This study compared the cyclic fatigue resistance and the mechanical, thermal, and metallurgical characteristics of SlimShaper® and SlimShaper PRO® instruments. Both sequences include three instruments (ZS1–ZS3) with identic...

The phenomenon of high-frequency distortion (HFD) in the electric grids, at both low-voltage (LV) and medium-voltage (MV) levels, is gaining increasing interest within the scientific and technical community due to its growing occurrence and the assoc...

This paper presents the development and characterization of a reference high-voltage sensing chain for the calibration and conformity assessment of instrument transformers with Class 0.1-WB3, in the extended frequency range up to 150 kHz, according t...

To address the “metering blind zone” problem in distribution networks caused by flood disasters, this paper proposes an optimal deployment strategy for low-voltage instrument transformers (LVITs) based on time-varying risk assessment. A c...

With the global trend to digitalize substation automation systems, International Electro technical Commission 61850, a communication protocol defined by the International Electrotechnical Commission, has been given much attention to ensure consistent...

An eddy current testing instrument is the core equipment for non-destructive testing (NDT) in nuclear power plants, and its performance is of great significance to ensure the safety of nuclear power units throughout their life cycle. At present, main...

For Chinese traditional musical instruments, the general subjective evaluation method by experts is not cost-effective and is limited by fewer and fewer experts, but a clear physical law is very hard to established by physicists. Considering the effe...

Absolute instrument refers to a media that can make light rays to propagate in a closed orbit and perform imaging and self-imaging. In the past few decades, traditional investigations into absolute instrument have been centered on the two-dimensional...

Fourier transform spectrometers (FTSs) are cornerstone instruments in Earth observation space missions, effectively monitoring atmospheric gases in missions such as Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), and Infrared Atmos...

This work deals with two paramount devices when Smart Grids are concerned: phasor measurement units (PMUs) and low-power instrument transformers (LPITs). In particular, a simple calibration procedure to test the measurement chain PMU + LPIT has been...

In this paper, we consider the calibration of measuring bridges for non-conventional instrument transformers with digital output. In this context, the main challenge is represented by the necessity of synchronization between analog and digital output...

In Fourier Transform Spectrometers, phase errors in spectral measurement induce distortion in reconstructed spectra. Existing phase correction algorithms demonstrate insufficient precision in addressing both linear phase and instrumental phase compon...

The concept of risk is fundamental in various scientific fields, including physics, biology and engineering, and is crucial for the study of complex systems, especially financial markets. In our research, we introduce a novel risk model that has a na...

The converter transformer is a special power transformer that connects the converter bridge to the AC system in the HVDC transmission system. Due to the special structure of the converter transformer, it is necessary to test its operation state durin...

Power quality is a wide-ranging and current topic that involves a huge effort from the scientific community. Power quality issues have to be avoided or solved in order to preserve the integrity of the network and its assets. To this purpose, several...

Power quality evaluation is the process of assessing the actual power network parameters with respect to the ideal conditions. However, several new assets and devices among the grid include mining the voltage and current quality. For example, the pow...

This paper presents a novel method for assessing the technical condition of devices in the high-voltage (HV) switching bay of a substation, focusing on circuit breakers, disconnectors, and instrument transformers. These devices are typically maintain...

This paper analyzes the impact of typical DC transient events occurring in railway grids on the frequency performance of instrument transformers (ITs) installed onboard trains and in AC substations for power quality (PQ) applications. PQ monitoring i...

Low-Power Instrument Transformers (LPITs) are becoming the first choice for distributed measurement systems for medium voltage networks. However, there are still a lot of challenges related to their operation. Such challenges include their accuracy v...

Cotton micronaire (MIC) is an essential fiber quality index that characterizes both fiber maturity and fineness components. This study compared how MIC affects the fiber high volume instrument (HVI) and advanced fiber information system (AFIS) qualit...

Large-scale renewable energy plants, flexible AC (alternating current) and high voltage DC (direct current) transmission systems, and modern consumer devices utilize power electronics that tend to increase harmonic emissions. Furthermore, such emissi...

There has been an interest in understanding the relationship between textile cotton fiber strength (or tenacity) and structure for better fiber quality measurement and enhancement. This study utilized coupled Stelometer and high volume instrument (HV...

We formulate a general program for describing and analyzing continuous, differential weak, simultaneous measurements of noncommuting observables, which focuses on describing the measuring instrument autonomously, without states. The Kraus operators o...

The remote calibration of instrumentation transformers is theoretically possible using synchronous measurements across a transmission line with a known impedance and a local set of calibrated voltage and current transformers. In this paper, an extens...

Communication protocols play a pivotal role in the substation automation system as they carry critical information related to asset control, automation, protection, and monitoring. Substation legacy protocols run the assets’ bulk data on multip...

Cotton fiber length and maturity, two critical fiber qualities, are commonly determined in the U.S. by Uster high volume instrument (HVI) and advanced fiber information system (AFIS). The main objectives of this investigation were to compare how HVI...

This paper explores the dynamic behavior of different wood species in the form of violin boards, based on experimental modal analysis using a single-input, multiple-output configuration. Thus, two groups of species were studied: the first group for t...

The detection of acoustic emissions with multiple channels and different kinds of sensors (external ultrasound electronic sensors and internal optical fiber sensors) for monitoring power transformers is presented. The source localization based on the...

Deep hole measurement is a crucial step in both deep hole machining and deep hole maintenance. Single-camera vision presents promising prospects in deep hole measurement due to its simple structure and low-cost advantages. However, the measurement er...

Conventional current transformers (CTs) suffer from nonlinearities due to their ferromagnetic cores. On one hand, it is well-known that severe core saturation may occur because of large overcurrents or unidirectional transient components: this may su...

The paper presents a method for the frequency characterization of voltage transformers (VTs) for medium voltage (MV) grids which involves only sine waves. It is called extended SINDICOMP, since it is an extended version of the previously developed te...

In this paper, we present an investigation into the influence of the load power factor of secondary winding on the metrological performance of inductive CTs with frequencies from 50 Hz to 5 kHz of the harmonic of a transformed distorted current. The...

International technical committees put considerable efforts into the writing process of standards. They always try to find a tradeoff between the rigorous scientific requirements and the practical needs of manufacturers and final users. In addition,...

Inductive current transformers are characterized by different transformation accuracies for higher harmonics of distorted primary currents. Therefore, it is highly required to perform the tests of their metrological properties to choose the best unit...

This manuscript presents performed laboratory studies and the analysis of the impact of current shunt values used in the differential connection on the wideband metrological performance of inductive current transformers. Moreover, a comparison of the...

In this work, a new methodology is proposed for the online and non-invasive extraction of partial discharge (PD) pulses from raw measurement data obtained using a simplified setup. This method enables the creation of sub-windows with optimized size,...