Diagnostics capabilities of various electrical anomalies in Smart Grids (original) (raw)

Detection of Anomalies in the Quality of Electricity Supply

International Journal on Future Revolution in Computer Science & Communication Engineering , 2018

From the last two decades, power quality is getting much attention. Proper functioning of the equipment depends upon the quality of power supplied. Every year, demand of electric power goes on increasing and the power system network is expanding and becoming more complex. On account of thrust on clean power supply, use of renewable sources has dramatically increased in grid but it simultaneously causes power quality problems. In this work, power quality disturbance detection in wind farm integrated with grid is presented. For disturbance detection, time-time transform has been employed. The disturbance signal for the detection purpose is generated in MATLAB/Simulink environment by using a Simulink model.

Techniques used for Detection of Power Quality Events – a Comparative Study

2010

This paper presents the analysis of different techniques used for the detection of various power quality disturbances such as voltage sag, swell, interruption and harmonics. Fast Fourier transform technique applied to analyze the voltage signal can correctly identify the magnitudes and phase of harmonic components present in the signal. But it does not give the time information of these harmonics in the analyzed signal. Also, Fast Fourier Transform cannot detect disturbances such as voltage sag, swell and interruption. Measurement of RMS is applied to overcome this. But this method is affected by the instant at which the disturbances occur and hence introduce error in the calculated duration of disturbance. Wavelet Transform of a disturbance signal can detect these disturbances accurately-the magnitude and time information. S-Transform application to detect disturbances is also introduced in this paper, which gives phase information of the harmonics and has capability to detect sag,...

An Application of Spectral Kurtosis to Separate Hybrid Power Quality Events

Energies, 2015

For the development of the future smart grid, the detection of power quality events is a key issue for the power system monitoring. Voltage sags, swells, harmonics (variations) and interruptions, which produce large losses for commercial and industrial consumers, are the main events to be considered due to the sensitivity of equipment to these electrical anomalies. The steady-state events are even more frequently accompanied by transients, the discrimination and localization being far more exigent and requiring advanced signal separating tools to be incorporated in the measurement equipment. This paper shows the event detection performance of the spectral kurtosis as a signal separating tool in the frequency domain. The disturbances under test are hybrid signals resulting from the coupling between amplitude defects and non-desired higher frequencies. Being a fourth-order spectrum, the kurtosis is confirmed as a noise-resistant tool that enhances impulsiveness, therefore characterizing the electrical anomalies. In the beginning of the analysis, the voltage sag is established as a reference; then, the disturbances (oscillatory transients and harmonics) are coupled at the starting and ending instants of the sag, resulting in complex hybrid events. The results show that the spectral kurtosis enhances the detection Energies 2015, 8 9778 of both types of events (steady state and transients), which are outlined in a bump shape in the fourth-order frequency pattern and centered in the main carrier frequency. Indeed, while the oscillatory transients are associated with softer and lower-amplitude peaks, the harmonics correspond to crisper and higher ones. As these mixed electrical faults are very common in the actual power grid, the article postulates the higher-order spectra to be implemented in prospective online measurement instruments.

Detection and Comparison of Power Quality Disturbances using Different Techniques

International Journal of Computer Applications, 2013

Poor power quality can cause serious problems causing malfunction, instability, short lifetime, memory loss and data errors of sensitive loads etc. Electric power quality has become an important issue now days. To improve the power quality, sources of disturbances as well as detection techniques must be known. The purpose of this paper is to present different detection techniques for sag, swell, harmonics and make comparison between them. Signal processing techniques are used to extract features from measured data and detect triggering points or transition segment of disturbances.

Techniques to Locate the Origin of Power Quality Disturbances in a Power System: A Review

Sustainability

The complexity in the power system topology, together with the new paradigm in generation and demand, make achieving an adequate level of supply quality a complicated goal for distribution companies. The electrical system power quality is subject to different regulations. On one hand, EN-50160 establishes the characteristics of the voltage supplied by public electricity networks, therefore affecting distribution companies. On the other hand, the EN-61000 series of standards regulates the electromagnetic compatibility of devices connected to the network, therefore affecting the loads. Power companies and device manufacturers are both responsible and affected in the issue of quality of supply. Despite the regulations, there are certain aspects of the supply quality that are not solved. One of the most important is the location of the disturbance’s origin. This paper presents a review of the main techniques to locate the disturbance’s origin in the electric network through two approach...

Special Issue “Analysis for Power Quality Monitoring”

Energies, 2020

We are immersed in the so-called digital energy network, continuously introducing new technological advances for a better way of life. As a consequence, numerous emerging words are relevant to this point: Internet of Things (IoT), big data, smart cities, smart grid, industry 4.0, etc. To achieve this formidable goal, systems should work more efficiently, a fact that inevitably leads to power quality (PQ) assurance. Apart from its economic losses, a bad PQ implies serious risks for machines and, consequently, for people. Many researchers are endeavouring to develop new analysis techniques, instruments, measurement methods, and new indices and norms that match and fulfil the requirements regarding the current operation of the electrical network. This book, and its associated Special Issue, offer a compilation of some of the recent advances in this field. The chapters range from computing to technological implementation, going through event detection strategies and new indices and meas...

Power system disturbance monitoring using spectral analysis techniques

1995

This paper considers the problem of measuring and analysing the frequency and phase angle variations which occur in a power system after a fault or disturbance. This is an important problem because the results of the analysis are used in implementing control strategies to avert generat,or cutout. Commonly, the frequency is not measured directly, but is inferred from the instantaneous power at the substation. Since there is a complicated non-linear relationship between the power and the frequency, some bias is incurred in the measurement. This paper proposes instead that the angle and or frequency be obtained directly via an analytic signal readily constructed from the 3-phase output of the power system. The paper also proposes enhancements for some of the currently employed signal analysis techniques, and a new technique based on an extension of Thompson's harmonic line test.

Harmonic Power Angle Monitoring for Unsymmetrical Fault Diagnosis in Distribution Network

2017

In this paper identification of a faulty load bus has been done in a multi-bus power system for double line fault, monitoring the feeder operating points and load angles in presence of various frequencies in harmonic P-δ plane. The usage of a new advanced variable slack bus incorporated converged power flow analysis determines the load angle, real power and feeder operating points for normal and fault in various load buses of the network in presence of some chosen harmonic frequencies in the system. The characteristic operating point shifting of the normal and fault operating points in normal and fault P-δ planes, determines the rule sets for identifying the fault buses in the grid system considered. This analysis can also be extended for other fault analysis in both online and offline conditions of the system.