1,721,044 research outputs found
A Smart Frequency Domain-Based Modeling Procedure of Rogowski Coil for Power Systems Applications
Full text linkRogowski coils are key measurement instruments in several applications due to their flexibility, large bandwidth, linearity, and so on. Like the majority of the instrument transformers (ITs), Rogowski coils are standardized and their use is regulated almost for every application. This article focuses on a smart way for the equivalent parameters' computation of the Rogowski coil. The parameter computation is performed by evaluating the Rogowski response when subjected to a single waveform generated to fulfill a specific requirement on its frequency content. Results demonstrate the equivalency of the presented method compared to the typical frequency sweep test. In addition, the results have been used to validate Rogowski's output estimate procedure presented by the authors in a previous work
Uncertainty and Lack of Information Affecting the Training of Machine Learning Algorithms for Fault Prediction of Cable-Joints
No full textArtificial intelligence (AI) and machine learning algorithms are becoming more and more popular in power system applications. Their benefits have been proven in many different fields, and power systems will benefit from them too. For example, AI allows the analysis of huge amounts of data which could not be treated otherwise. Furthermore, well-trained algorithms may automatize operations which typically need a dedicated operator. A limit to the implementation of AI in power systems is the uncertainty. It can be divided into three main contributions: the uncertainty of the algorithms results, the uncertainty of the input data, and the lack of experience, information, or unique solutions associated to a specific application. Therefore, this paper aims to include the latter two uncertainty contributions into machine learning algorithms. Their output is used for the fault prediction of medium voltage cable joints, providing information about their health status. As a matter of fact, it is still not possible to exactly predict the cable joint fault. Therefore, such an application is a significant case study to address the uncertainty contributions affecting the training of machine learning algorithms. The obtained results clearly demonstrate the effect of the sources of uncertainty on the algorithm performance
Effects of load unbalance on multi-point measurement techniques for assessing the responsibility for PQ degradation
No full textOn the characterization of voltage and current transducers in steady-state distorted conditions
No full textThe traceability of measurements performed to gauge information about the operation of electrical power systems under nonsinusoidal conditions is an important and live issue, usually neglected by the technical Standards. A generalized definition of the “composite error” is proposed in this paper as a meaningful index for the metrological characterization of voltage and current transducers in steady-state nonsinusoidal conditions. In this connection, the relationship among the composite error, the classical ratio and phase-angle errors and other parameters characterizing the waveforms of the transduced quantities are pointed out. Finally, problems involved in the measurement of the composite error in steady-state distorted conditions are dealt with and the results of some experimental work are presented
A test system for the evaluation of the expanded uncertainty in DSP-based analysis of bi-tone signals
No full textFast calibration procedure for low power voltage transformers up to 2.5 khz using sinc response
No full textA The progressive deployment of Low Power Instrument Transformers in power network for measurement purposes requires studies on their characterization and on the effect of different quantities on their accuracy. In this paper, a fast calibration procedure is introduced. By using a sinc signal, a Low Power Voltage Transformer has been characterized in the power quality frequency range (50 Hz to 2.5 kHz) under the rated voltage conditions
Fault location in underground power networks: A case study
No full textThe present paper addresses the topic of fault location in power networks with cable lines. In the era of smart-grid the demand of intelligent measurement systems capable of providing quickly and with high accuracy the right location of faults in power networks is growing fast. Many proposals can be found in literature relevant to different approaches. Some commercial instrumentation is also available on the market for this purpose. Protection relays implementing this feature can either be found. This paper presents the experimental results of a measurement campaign carried out in the MV power network in the city of Milan (Italy). For this purpose the local Utility (A2A SpA) is using a commercial distributed measurement system (the ALTEA FLS) for locating both faults and also fast transients due to customers' loads operation. Preliminary experimental results have shown good performance. They have been better analyzed in order to investigate over the reliability and the accuracy of such measurement system. © 2011 IEEE
- …
