Power Quality Monitoring System Research Articles

Novelty Detection on Power Quality Disturbances Monitoring

Complex disturbance patterns take place over the corresponding power supply networks due to the increased complexity of electrical loads at industrial plants. Such complex patterns are the result of a combination of simpler standardized disturbances. However, their detection and identification represent a challenge to current power quality monitoring systems. The detection of disturbances and their identification would allow early and effective decision-making processes towards optimal power grid controls or maintenance and security operations of the grid. In this regard, this paper presents an evaluation of the four main techniques for novelty detection: k-Nearest Neighbor, Gaussian Mixture Models, One-Class Support Vector Machine, and Stacked Autoencoder. A set of synthetic signals have been considered to evaluate the performance and suitability of each technique as an anomaly detector applied to power quality disturbances. A set of statistical features have been considered to characterize the power line. The evaluation of the techniques is carried out throughout different scenarios considering combined and single disturbances. The obtained results show the complementary performance of the considered techniques in front of different scenarios due to their differences in the knowledge modelization.

Design of Real-Time Power Quality Monitoring System for Active Distribution Network Based on Computer Monitoring

The power system is continuously optimized and advanced, and then various equipment auxiliary systems are produced. This paper studies the real-time power quality monitoring system of active distribution network based on computer monitoring. The system can monitor the real-time parameters of electric energy and the running status of equipment, and design the memory function and fault processing function. When some equipment or parts of the power grid failure, the system can produce alarm signals in a timely manner, notify the system monitor, the staff can immediately deal with the problems caused by the signal, reduce the loss caused by failure in time. The memory function of the system is to carry on the memory to the fault signal, then can quickly find, is advantageous to the fault study and the prevention.

Modeling and Simulation of Voltage Sag Assessment for Distribution Network Based on Total Coverage of Nodes

The evaluation of voltage sag of power grid is to analyze the situation of voltage sag, to guide the planning, construction and transformation of power grid, and further improve the power quality. It is an important content in the current power quality research. In this paper, the fault point is regarded as a new virtual node, and the fault location is described by fault location parameters λ. The system node impedance matrix is expanded by calculating the self impedance and mutual impedance between the virtual node and the concerned node. Through the modeling and simulation of distribution network, short-circuit faults are set to analyze the voltage sag. According to the three-phase voltage sag waveform recorded by power quality monitoring system (PQMS), the fault type can be identified, and the fault line can be determined according to the PDR of SCADA system. Without considering the fault resistance, the fault type and fault line are known, so the fault location can be found only by solving the fault location parameters λ. Because of its parallel processing and good robustness, particle swarm optimization algorithm can find the optimal solution of the problem with large probability and fast convergence speed, so this paper chooses to use particle swarm optimization algorithm to solve the fault location parameters λ.

Research on Distributed Power Quality Monitoring System of Large Centralized Charging Station

The power quality problems of large-scale centralized charging stations are prominent, affecting the operation of the station equipment and the power grid, and a simple and efficient distributed power quality monitoring system is required. Based on the analysis of large-scale centralized charging stations for distributed power quality monitoring system requirements, this paper studies the overall structure of the distributed monitoring system, and analyzes the functional requirements of each part of the monitoring system, and gives the voltage/current power quality Monitoring terminal functions and key device design; by comparing and analyzing the characteristics of various communication technologies, an optimal solution for the communication of the distributed monitoring system in the charging station is given. The proposed system provides a basis for real-time monitoring of multiple monitoring terminals in large-scale centralized charging stations, analysis and timely release of relevant power quality assessment information, and in-depth study of the power quality of various charging piles in the charging station and their mutual influence. At the same time, the formed “point-line-surface” charging station monitoring system can provide a data basis for smart operation and maintenance of charging stations.

Power quality monitoring system based on IEC61850

Power quality monitoring system is an important means to find and evaluate power quality problems in time. A service-oriented browser / server (B / S) mode active power quality real-time monitoring system is designed and implemented, which provides the real-time monitoring function of power quality in the process of active power distribution network absorbing distributed power generation layer by layer, and focuses on observing the impact of the change of power flow direction on the level of power quality. Based on IEC 61850 standard, the system establishes the power quality information model, and uploads the real-time monitoring data of power quality on site to the master station for analysis and storage in the real-time database through MMS. The client communicates with the server through windows communication base (WCF) service to obtain real-time monitoring data, and realizes the global real-time monitoring function of power quality of active distribution network combined with the main wiring diagram, so as to achieve the integrated display effect of data graph.

Power Quality Monitor Allocation Based on Singular Value Decomposition and Genetic Algorithm

This paper proposed a novel method for allocating power quality meters with the main objective of ensuring a completely observable power distribution system. The method was designed to establish the quantity, location and type of measurement to be performed (voltage and/or current) for a given distribution system by employing genetic algorithms and the principles of state estimation based on the singular value decomposition. Moreover, a limitation in the number of current measuring channels was inserted in the mathematical formulation as an alternative for reducing costs. The method has been validated by running a three-phase harmonic state estimation using the IEEE 34 and 37 bus distribution test feeders. The results demonstrated the effectiveness of the method for designing power quality monitoring systems in distribution grids, ensuring full observability for state estimation purposes.

Construction of a Power Quality Monitoring System Based on the Wavelet Transform Change-Point Detection Algorithm on the Virtual Instrument Platform

It is aimed to carry out the investigation on power quality detection, promote the realization of efficient transmission of network data, and expand the application of wavelet transform change-point detection algorithm in the monitoring system. The voltage deviation is used as a starting point to explore the detection of power quality. First, it describes the harmonics of the public power grid and the limits of harmonic voltage. Second, based on the virtual instrument platform, the power quality monitoring system based on wavelet transform change-point detection algorithm is completed. Finally, by adding a monitoring terminal and a service terminal, the design of the monitoring system server is completed. Through the analysis of the experimental results, it is found that in the monitoring system, the current waveform and the three-phase voltage can be accurately displayed. The combined design of the networked monitoring system and the system server enables the system to complete the rapid transmission of data related to power quality, while having a good monitoring effect. For the optimization of networked monitoring experienceof the server, the application of wavelet transform in power quality measurement is realized. The power quality monitoring system proposed has a strong practicality in power quality monitoring.

Design and Implementation of a Data-Driven Approach to Visualizing Power Quality

Numerous underlying causes of power-quality (PQ) disturbances have enhanced the application of situational awareness to power systems. This application provides an optimal overall response for contingencies. With measurement data acquired by a multi-source PQ monitoring system, we propose an interactive visualization tool for PQ disturbance data based on a geographic information system (GIS). This tool demonstrates the spatio–temporal distribution of the PQ disturbance events and the cross-correlation between PQ records and environmental factors, leveraging Getis statistics and random matrix theory. A methodology based on entity matching is also introduced to analyze the underlying causes of PQ disturbance events. Based on real-world data obtained from an actual power system, offline and online PQ data visualization scenarios are provided to verify the effectiveness and robustness of the proposed framework.

IoT embedded cloud-based intelligent power quality monitoring system for industrial drive application

It is essential to understand the quality of power being delivered to the industries that have equipment sensitive to power disturbances. Implementing IoT based power quality monitoring systems is a widespread practice in industries to prolong the process without any interruption. IoT based system looks very costly due to the data accumulation process which is carried over a long period requiring large data storage. Hence the paper proposes an intelligent power quality algorithm that alters data accumulation process more efficient by managing the power quality event data logging with pre-and-post value. The proposed system logs the drive’s mechanical quantities along with the power quality event data in Firebase cloud, which limits the space requirement and save time in analyzing the power quality events. Moreover, the power quality standards could be chosen by the end-users. Overall, the developed system is faster, economical and accurate and easier to operate, which can be used for many real-time applications.

Compression Method of Power Quality Disturbances Based on Independent Component Analysis and Fast Fourier Transform

In power quality monitoring systems, a large volume of data is generated. A compression method should be used to perform the storage of data more efficiently. The present study proposes a compression method of power quality disturbances based on independent component analysis, Fast Fourier Transform and an adaptive threshold obtained using mathematical morphology. The independent component analysis algorithm returns three statistically independent components among themselves. Considering the noise and disturbances are statistically independent of the fundamental component, the independent component analysis algorithm isolates the noise and disturbances in the third component, where a threshold is applied, while the first and second components are presented to the Fast Fourier Transform in order to characterize the fundamental component. The results were compared with a Wavelet-based method in which the proposed method achieved compression rates slightly higher than the Wavelet-based method.

An Innovative Approach to Express Uncertainty Introduced by Voltage Transformers

The importance of monitoring voltage harmonics in distribution grids has raised because of the increasing diffusion of power electronics-based nonlinear devices. In this respect, the role of voltage transformers (VTs) is vital since they represent the input stage in power quality monitoring systems, and they are responsible for one of the major uncertainty contributions. Nevertheless, their metrological performances are still quantified in terms of accuracy class, namely, rating maximum ratio error and phase displacement. The aim of this article is moving from the concept of maximum error to that of uncertainty, while proposing a new approach to evaluate and express the accuracy of VTs employed for harmonic measurements. The method is applied to the calibration of a conventional inductive VT by means of a proper setup that allows injecting complex multitone waveforms. Experimental results clearly show the advantages of the proposed approach, which permits a better description of the metrological behavior with respect to the usual ratio error and phase displacement.

Power quality monitoring system of distribution room based on distributed sensors

A large number of non-linear devices has been used nowadays. Therefore, the power quality problem on the user side is becoming significantly prominent. The power distribution room is the end of the power system, which is directly connected to the users. But distribution room has noneffective power quality monitoring system established due to difficulties of data measuring and installation. In this paper, based on micro distributed sensor with coil energy acquisition and wireless communication technology, a distributed power quality monitoring system is developed in distribution room, which can be implemented quickly and complete the monitoring and analysis of power quality information in the distribution room. The system realizes the function of design requirement through field test.

Voltage sag/swell waveform analysis method based on multi‐dimension characterisation

Voltage magnitude and sag duration are known as acknowledged basic voltage sag characteristics in the last decades. However, these values cannot meet the demands of waveform analysis in the modern smart grid. Therefore, voltage sag multi-dimension characterisation is required to extract more essential information from measured waveforms. This study focuses on the unsolved issue that how to obtain required characteristics from voltage sag waveforms effectively. Overall, multi-dimension characterisation method contains several parts: voltage sag detection, segmentation and characteristics calculation. Fundamental voltage magnitude and phase angle, obtained by the proposed adaptive generalised morphology filter, are segmented in several parts. Then, a set of characteristics are calculated to characterise the voltage sag waveform in a multi-dimensional way. Performance of the proposed method is validated by synthetic and measured waveforms. Results show that both detection and segmentation methods have better performance than existing typical methods, and multi-dimension characteristics can be extracted from waveforms accurately. Moreover, the proposed method can be implemented in power quality monitoring system to support further sag studies.

Comparative Analysis of Power Quality Monitoring Systems

Electricity is the most important commodity used in our daily routine and power quality (PQ) is gaining interest from last few years. A review of the techniques used for power quality monitoring is presented in this paper. Major focus of this paper is on power quality monitoring (PQM) and management systems in the area of power industry. Techniques reviewed in this paper also include some power quality meter placement techniques. Efficiency and cost effectiveness of PQM system can be improved by applying the techniques that find the optimum number of monitors to be placed and the best locations where they have to be placed and these techniques are called power quality meter placement techniques. In this review initially methodology of each method is defined and then comparison between them is presented. Power quality monitoring and management strategies that are used internationally in industries are discussed and at the end some examples are presented that defines the efforts made in the area of power quality improvement.

Design of Power Quality Monitoring System Based on Industrial Ethernet

An embedded Ethernet based on microcontroller ADUC812 and industrial Ethernet controller 8019AS are designed to deal with the problems of power quality monitoring system. This paper proposed a two-level power quality monitoring system which consisting of a general control layer and a field monitoring layer, the monitoring system is used to monitor the three-phase voltage, current and neutral current RMS of power network as well as other parameters in real-time, including three-phase unbalance, power factor, and power frequency. The main computer uses Lab VIEW as programming software to perform all the functions required for monitoring in the form of animations, charts, curves and virtual panels. This system not only has the feature of being easy to expand the functions and flexible configuration, but also has a high cost performance. So, it can meet the power quality monitoring requirements of modern industrial and civil constructions.

Design of distributed power quality monitoring system for distribution house

The construction of smart grid puts forward higher requirements for power quality. As the key node of power distribution system, power quality monitoring of distribution room has always been the weak link of power operation and maintenance. This paper presents a distributed power quality monitoring system for distribution room, which includes hardware design and software design. It has the functions of acquisition, analysis, display and communication. It can complete distributed power quality monitoring for multiple outgoing branches of distribution room. The application of this system can provide data support for power quality analysis and management of low-voltage distribution system.

Power quality analysis for greener shipping by implementing an on-board electric power quality monitoring system

ABSTRACT This paper presents a methodology for the development and installation of an electric power quality monitoring system onboard a ship, for managing and optimising the electric power of critical loads that have a significant effect upon the overall ship efficiency as outlined by the International Maritime Organization rules. The improvement of overall ship efficiency is attained by installing power converters to electrically driven loads that play a key role in the ship operation. The outcome of this methodology is a system comprising measuring devices for recording both voltage and current. The data loggers are interconnected via a local network –in this case is a WiFi network – to a computer located in the control room of the ship. The method described in this work was developed within the framework of a research project and the system was implemented onboard an actual oil tanker.

Reliable Power Quality Monitoring and Protection System

The principle goal is to add a GSM based vitality meter perusing framework and burden control through SMS. Power division sends workers to take meter perusing each month, which is a costly and tedious employment. The proposed venture gives a helpful and productive strategy to maintain a strategic distance from this issue. The power division and the client can get the readings of the vitality meter of buyers by means of SMS. The heaps can likewise be checked by the voltage level indicator.This undertaking likewise screens load control by sensor which it remove the framework when high or low voltage occurred.It utilizes a standard advanced vitality meter that conveys yield heartbeats to the microcontroller to perform meaning essential activity. On getting charge it can switch ON/OFF the heaps

Method for detecting harmonic responsibility misjudgements based on waveform correlation analysis

In this study, a method for detecting misjudgements in customer harmonic responsibility determination is proposed. The method is based on waveform correlation analysis. The quantitative relationship between waveform correlation coefficients and equivalent harmonic current injections is studied and discussed through theoretical derivations. The complete harmonic responsibility misjudgement detection method is then proposed on the basis of quantitative analysis and validated by means of simulation studies and field tests. The method has the ability of detecting harmonic responsibility misjudgements made on linear inductive loads using direct harmonic current measurement indices. On-line detection of misjudgements made by power quality monitoring systems in harmonic responsibility incentive management can be achieved by the proposed method.

Statistical control chart based harmonic amplification detection

With the rapid growth of nonlinear and fluctuating loads such as high-speed railways and converter stations, the problem of harmonic pollution is becoming more and more serious. The economic loss and social impact caused by harmonic amplification are increasingly prominent. On-line harmonic amplification detection with power quality monitoring system can identify problems and take measures in time. This paper proposes a method for online recognition of harmonic amplification based on statistical control chart. Firstly, based on the recent data the steady-state Xbar-S statistical control chart is constructed, by which the online data is identified whether it is abnormal. Secondly, it detects a harmonic amplification event by comparing its cumulative features containing Continuous time and distortion level of abnormal data segment with thresholds. The effectiveness of the method is verified based on the measured data.