Wide Area Measurement Research Articles

Cloud Simulation and Virtualization for Testing of Critical Energy Infrastructure Components

Cloud computing and cloud infrastructure are beginning to be applied in order to ensure effective functioning of management system of Critical Energy Infrastructure. This is improved informativeness of Supervisory Control and Data Acquisition system by the application of additional Wide-area Measurement and Control Systems (WAMCSs), since most of all processing and transition operations of data information streams of the WAMCSs may be performed by using on clouds. In light of these circumstances, it is importantly to get extensive modeling results considering wide area range of input data and latency time between critical energy infrastructure components and cloud infrastructure components. However, researchers were not, yet, had possibility to receive more adequate results based only mathematical modeling process. In this case, simulation models considering the cost time are more preferable than mathematical models. In the spirit development of this conception, authors are proposing to employ the simulation model based on virtual technology and Matlab Simulink toolkit in order to get modeling results for more important on-line mode of functioning of the WAMCSs.

A demonstration of spatial heterodyne spectrometers for remote LIBS, Raman spectroscopy, and 1D imaging

Three spatial heterodyne Raman spectrometers, one free standing, the others monolithic, have been used for remote Raman and LIBS for samples at a distance of 4.5 m and 1D Raman imaging. The wide area measurement capability of the SHS was demonstrated and shown to reduce sample photodegradation in the case of Raman, using large laser spots on the sample, without loss of signal or decreased spectral resolution. 1D Raman imaging using a free standing SHRS and a monolithic SHRS was demonstrated and shown to provide better signal-to-noise ratio (SNR) spectra for heterogenous samples than spectra measured without imaging. Improved SNR using 1D imaging is the result of spatial separation of the signal from different areas of the sample, which reduces the contribution of shot noise from stronger scattering sample regions to more weakly scattering adjacent sample regions. For 1D imaging of adjacent samples, within the field-of-view (FOV) of the spectrometer, the SNR improved up to four times, with no loss of spectral resolution or spectral range, and a spatial resolution of 280 μm was demonstrated for samples located at 4.5 m from the spectrometer.

Communication infrastructure for situational awareness enhancement in WAMS with optimal PMU placement

Real time monitoring and control of a modern power system has achieved significant development since the incorporation of the phasor measurement unit (PMU). Due to the time-synchronized capabilities, PMU has increased the situational awareness (SA) in a wide area measurement system (WAMS). Operator SA depends on the data pertaining to the real-time health of the grid. This is measured by PMUs and is accessible for data analytics at the data monitoring station referred to as the phasor data concentrator (PDC). Availability of the communication system and communication delay are two of the decisive factors governing the operator SA. This paper presents a pragmatic metric to assess the operator SA and ensure optimal locations for the placement of PMUs, PDC, and the underlying communication infrastructure to increase the efficacy of operator SA. The uses of digital elevation model (DEM) data of the surface topography to determine the optimal locations for the placement of the PMU, and the microwave technology for communicating synchrophasor data is another important contribution carried out in this paper. The practical power grid system of Bihar in India is considered as a case study, and extensive simulation results and analysis are presented for validating the proposed methodology.

Synchronous measurement technology of source-grid-load in renewable energy power system

In this paper, the technology of synchronous phasor measurement and its application in power system transient stability prediction and control, state estimation and dynamic monitoring, fault location is introduced. The construction method of wide area measurement system based on synchronous phasor measurement technology is puts forwarded. The important role of synchronous phasor measurement technology in these fields and its significance to power system security are analysed.

Data-driven detection for GPS spoofing attack using phasor measurements in smart grid

As the “GridEye”, the wide area measurement system (WAMS) can provide the synchronized measurements for many applications in smart grid based on the geographically dispersed phasor measurement units (PMUs). However, most PMUs rely on the civil GPS/BDS (BeiDou navigation satellite system) signal as the time source and are vulnerable to GPS spoofing attack (GSA), which would deteriorate the PMU based applications. Compared to cyber-attack, the GSA can destroy the data integrity without the need of access to the physical network which makes the GSA more threatening. In this paper, two simple but effective and automatic detection methods for the GSA are proposed, which are based on monitoring the changes of estimated line reactance using PMU data: 1) method based on historical statistics and 2) method based on abrupt change index which is widely used in digital relays. In addition, the types of GSA can be identified. The proposed methods are data-driven, i.e., it needs the PMU data at both ends of the transmission line and does not require knowing the line parameters and the system topology. The adaptive thresholds are used to make the methods determine the threshold automatically and balance the sensitivity and robustness for GSA detection. The reliability and superiority of the proposed methods are demonstrated with simulated and measured PMU data.

Reliability Analyses of Wide-Area Protection System Considering Cyber-Physical System Constraints

Wide-area measurement, protection and control systems link the cyber power system with the physical power system to realize a cyber-physical power system (CPPS). This paper proposes a reliability modeling and assessment method for the wide-area protection system (WAPS). The proposed WAPS model takes into account the decision accuracy of protection algorithms with limited available data at the control center, and combines it with the tripping reliability of protection devices in corresponding substations to form the operation accuracy of WAPS. In particular, the directional comparison algorithm used in decision-making is functionally divided into three modules, namely the initiation module, the fault area positioning module, and the faulted element recognition module. The proposed reliability models are established based on the Permutation and Combination method under the assumption that the data acceptance rate of the control center is d. The sequential Monte-Carlo simulation is used to solve the proposed reliability indices. Finally, the WAPS reliability assessment is presented for the IEEE 14-bus system and the key influencing factors are identified and discussed.

A model‐based method for rotor speed estimation of synchronous generators using wide area measurement system

In this paper a novel method is proposed to estimate the rotor speed of synchronous generators in steady state and dynamic conditions using phasor measurement unit's data. This method uses the synchronous generator model to find the relationship between generator rotor speed and frequencies at different buses of the power system. The principles of the proposed method are first presented through a simple network consisting a generator connected to a transmission line. Afterward the general formulation is developed. To demonstrate the effectiveness of our method, IEEE 9-bus and IEEE 39-bus power systems are used as the benchmark systems. Different tests are carried out under three conditions including, normal condition, presence of measurement errors and uncertainty of the power system parameters. As well, the estimation results are compared with the results of other estimation methods. The results show the high accuracy of the proposed method in different conditions.

Wide area monitoring and measurements using mixed integer linear programming in deregulated power system for smart grid

This paper deals with different methods involved in the determination of complete observability of power system under wide area monitoring using Phasor Measurement Unit (PMU). There are numerous methods available in literature for the determination of optimal locations of PMU for complete system observability, but out of all those methods, fast selection of best suitable with minimum number of PMUs at optimal location for complete observability, is still a challenge to power engineers for applying online in Smart Grid under deregulation environment. After detail analysis with various methods, this paper proposes an algorithm for selecting best possible method for determining optimal locations of PMUs. The analysis compares performance of the available methods, e.g., Binary Integer Linear Programming, Admittance Bus Matrix Method and Mixed Integer Linear Programing using General Algebraic Modelling System. To investigate the effectiveness of the proposed method for complete observability using system observability redundancy index (SORI), Indian Northern Regional Power Grid (NRPG-246 bus system) has also been considered here.

Latencies in Power Systems: A Database-Based Time-Delay Compensation for Memory Controllers

Time-delay is inherent to communications schemes in power systems, and in a closed loop strategy the presence of latencies increases inter-area oscillations and security problems in tie-lines. Recently, Wide Area Measurement Systems (WAMS) have been introduced to improve observability and overcome slow-rate communications from traditional Supervisory Control and Data Acquisition (SCADA). However, there is a need for tackling time-delays in control strategies based in WAMS. For this purpose, this paper proposes an Enhanced Time Delay Compensator (ETDC) approach which manages varying time delays introducing the perspective of network latency instead dead time; also, ETDC takes advantage of real signals and measurements transmission procedure in WAMS building a closed-loop memory control for power systems. The strength of the proposal was tested satisfactorily in a widely studied benchmark model in which inter-area oscillations were excited properly.

Improved Design of Interval Type-2 Fuzzy based Wide Area Power System Stabilizer for Inter-area Oscillation Damping

The interconnection of power system due to the ever-time increase in power demand has caused inter-area oscillations as a challenge to power system stability. The present paper proposes the novel design of an Interval Type-2 Fuzzy based Wide Area Power System Stabilizer to damp the inter-area mode of oscillations for improving the power system stability. The usage of Wide Area Measurement Systems for continuous monitoring of the power grid plays a significant role in maintaining the stability of the power grid. The proposed controller uses wide-area signals from WAMS as the input signals. The controllability index calculation performs the selection of the most affected wide-area signals. The participation factor is used to identify the location of the controller. Sliding Surface approach is introduced in the controller to upgrade the performance of the controller during different operating conditions. The sliding surface approach has made the system insensitive to the parameter variations. The interval type-2 fuzzy control is a model-free approach with better control performance, due to its higher degree of freedom of interval type-2 fuzzy sets. Finally, the optimal tuning of sliding surface parameters has been considered as an optimization problem with the minimization of Integral Time Square Error using Real Coded Genetic Algorithm to enhance the damping control. The proposed Fuzzy controller has been tested in two area, four machine, 11 bus IEEE benchmark system. From the simulation responses and the comparison with different controllers, the proposed controller shows robustness and effectiveness with more accurate dynamic response and better damping of inter-area oscillations under different system operating conditions and load perturbations.

Integrated Wide-Area Backup Protection Algorithm During Stressed Power System Condition in Presence of Wind Farm

Stressed power system conditions such as power swing, voltage instability and load encroachment may influence the secure operation of conventional backup protection at their third zone (zone 3). In this paper, a new integrated backup protection algorithm for distance relay is proposed based on wide-area measurements to distinguish the fault-stress conditions in the presence of offshore wind farm (WF). Presence of WF creates problem for distance relay due to varying wind speed and wide fluctuations in voltage and current signal during fault condition. In this work, two criteria are proposed to analyze and to identify the events. The first criterion compares the positive-sequence bus voltages in order to identify the faulty bus. According to second criterion, the absolute positive-sequence impedance angle difference between the lines connected to that faulty bus is computed to identify the faulty line. Numerous test cases with the WSCC 3-machine, 9-bus and IEEE 39 bus power system models have been simulated using EMTDC/PSCAD software. Results for different fault cases, power swing, load encroachment and voltage instability, and various non-fault cases like capacitor switching, demonstrate the efficacy of the wide-area backup protection scheme. Comparative assessment reports with the existing methods are also presented.

An Improved Dynamic Thermal Current Rating Model for PMU-Based Wide Area Measurement Framework for Reliability Analysis Utilizing Sensor Cloud System

Information technology expressively improves remote electricity measurement and monitoring. Integrating Dynamic Thermal Current Rating (DTCR) software packs with the exclusive phasor measurement-based Wide Area Measurement (WAM) framework, the remote Transmission Lines (TLs) current rating can be measured. WAM is used for data acquisition from different sensors, and also allows data transmissions and processing for which sensor cloud system (SCS) plays a vital role. DTCR with phasor-measurement based WAM framework is mainly used to analyze and determine the current ratings of overhead TLs using weather condition estimation or prediction methods. However, the recent study suggests that the accuracy of the DTCR has become an issue in the smart grid of Sarawak Energy Berhad (SEB). Hence, this article studies and discusses the relevant models and systems, and then proposes an improved thermal pi (π) model for the transmission line thermal model of DTCR software in WAM Framework. The performance of the improved π model will be distinguished from the existing thermal model. The weather factors that bring a substantial impact on the current rating is also considered, where the relevant data is monitored via different weather sensors. Besides, this study also focuses on calibrating the DTCR through phasor measurement in the WAM system, as well as the field measured data. All the data is collected from relevant sensors, and a detailed comparative analysis is provided based on the proposed model for the sake of improving the reliability of the system. The performance analysis of the thermal models is evaluated using Matlab software-based numerical analysis.

Communication Delay Modeling for Wide Area Measurement System in Smart Grid Internet of Things Networks

We present communication frameworks, models, and protocols of smart grid Internet of Things (IoT) networks based on the IEEE and IEC standards. The measurement, control, and monitoring of grid being achieved through phasor measurement unit (PMU) based wide area measurement (WAM) framework. The WAM framework applied the IEEE standard C37.118 phasor exchange protocol to collect grid data from various substation devices. The existing frameworks include the IEC 61850 protocol and programmable logic controllers (PLCs) based supervisory control and data acquisition (SCADA) system. These protocols have been selected as per the smart grid configuration and communication design. However, the existing frameworks have severe synchronization errors due to the communication delays of IoT networks in the smart grid. Therefore, this article designs the timing mechanism and a delay model to reduce the timing delay and boost real‐time measurement, monitoring, and control performance of the smart grid WAM applications. The result shows that the proposed model outperformed the existing WAM system.

A Novel Thévenin Equivalent Model Considering the Correlation of Source-Grid-Load in Power Systems

The coupled single-port circuit has been proposed for online voltage stability assessment based on wide-area measurements and grid equations. This circuit can explicitly reflect the influence of grid and load on voltage stability. However, it does not consider the impact of power generation. A novel Thevenin equivalent (TE) circuit considering the influence of source-grid-load on voltage stability is proposed in this paper. First, the impact of source-grid-load on the voltage of an individual load bus is divided into three parts according to the node-voltage equation. They are then decomposed into two components, respectively associated with the TE voltage and the TE impedance according to the TE circuit’s characteristics. Finally, an online identification method for the parameters of the proposed TE circuit based on wide-area measurements is developed. Compared with the coupled single-port circuit, the proposed method has the advantage of being able to consider the influence of power generation on voltage stability and being consistent in form with traditional TE circuit without requiring approximation. Case studies on the IEEE 118-bus system illustrate the accuracy and effectiveness of the proposed method.

Research on the model of smart grid wide-area measurement cyber-physical fusion system based on data fusion

Due to price and technical reasons, it is currently impossible to install phasor measurement units in the entire network. How to use the minimum number of phasor measurement units to maximize the observation of the state or dynamic behavior of the power grid is the first consideration for the wide-area measurement system at this stage. This paper proposes a method to optimize the configuration of the phasor measurement unit while ensuring that the power grid is fully observable and can capture the dynamic behavior of the power grid under transient conditions. This paper proposes a load modeling method based on wide-area measurement. Aiming at the problems of traditional large-area power grid load modeling based on load characteristic measurement devices and the characteristics of the current wide-area measurement system, a load modeling method based on local PMU observations is proposed. This method combines particle swarm optimization algorithm and time. Domain simulation calculation can identify the load models at all load nodes of the system at the same time. This paper proposes a CPPS information flow transmission model based on graph theory and information flow dynamics. This model considers the coupling effect of CPPS, the processing capacity of communication equipment and the transmission mode of CPPS information flow, and constructs a CPPS dynamics model from the perspective of communication transmission. In the analysis of the calculation example, by applying the information flow transmission model to CPPS topologies generated by different scales and different modeling methods, the influence of network scale, key nodes and network topology structure on the efficiency of CPPS information transmission was explored, and the effectiveness of the model was verified.

Wide Area Measurement System in the IEEE-14 Bus System using Multiobjective Shortest Path Algorithm for Fault Analysis

In a large-scale interconnected power system network, few challenges exist in evaluating and maintaining the overall system stability. The power system’s ability to supply all types of loads during natural disasters or faults has yet to be addressed. This work focuses on developing a wide-area measurement system to manage and control the power system under all operating conditions. The IEEE-14 bus system was modeled in PSCAD software for simulating nineteen types of fault based on multi-objective shortest path algorithm. To manage the wide area measurement, the research must comprehend the working principle of the multi-objective shortest path algorithm, whereby the proposed method will determine the new path for the IEEE-14 bus system. To evaluate the performance of the multi-objective shortest path algorithm, all sections of the IEEE-14 bus system were simulated with faults. The distances of the normal path (without simulated fault) and the new path (with simulated fault) were recorded. Based on the recorded data, it was found that the location of the fault has significant influence on the shortest path of the buses connected to each other.

Antenna Designs for CubeSats: A Review

Cube Satellites, aka CubeSats, are a class of nano satellites that have gained popularity recently, especially for those that consider CubeSats as an emerging alternative to conventional satellites for space programs. This is because they are cost-effective, and they can be built using commercial off-the-shelf components. Moreover, CubeSats can communicate with each other in space and ground stations to carry out many functions such as remote sensing (e.g., land imaging, education), space research, wide area measurements and deep space communications. Consequently, communications between CubeSats and ground stations is critical. Any antenna design for a CubeSat needs to meet size and weight restrictions while yielding good antenna radiation performance. To date, a limited number of works have surveyed, compared and categorised the proposed antenna designs for CubeSats based on their operating frequency bands. To this end, this paper contributes to the literature by focusing on different antenna types with different operating frequency bands that are proposed for CubeSat applications. This paper reviews 48 antenna designs, which include 18 patch antennas, 5 slot antennas, 4 dipole and monopole antennas, 3 reflector antennas, 3 reflectarray antennas, 5 helical antennas, 2 metasurface antennas and 3 millimeter and sub-millimeter wave antennas. The current CubeSat antenna design challenges and design techniques to address these challenges are discussed. In addition, we classify these antennas according to their operating frequency bands, e.g., VHF, UHF, L, S, C, X, Ku, K/Ka, W and mm/sub-mm wave bands and provide an extensive qualitative comparison in terms of their size, -10 dB bandwidths, gains, reflection coefficients, and deployability. The suitability of different antenna types for different applications as well as the future trends for CubeSat antennas are also presented.

Application of standard ZET-algorithm for gaps filling in wide area measurement system data assets

This article explores the application of Standard ZET-algorithm for gaps filling in Synchronized Phasor Measurement data assets received from Wide Area Measurement Systems. In spite of Synchronized Phasor Measurement data assets apparent advantages, they have gaps affecting the accuracy of solving power engineering tasks. Authors analysed the reasons of gap occurrence in data assets, provided experiments with voltage and current data assets and collected the key points about application of Standard ZET-algorithm.

Communication Network for Smart Microgrid

This paper conveys development, validation and performance analysis of a communication network for facilitating bi-directional communication in a microgrid adhering to smart grid communication standards. The work encompasses proposing a suitable topology for the communication network and communication technology selection from among technologies like IEEE 802.3, 802.11, 802.15.4 for data transfer by performing communication network simulation in Netsim, a network simulation software. The simulation in Netsim delivers the performance of communication network for various technologies through performance indices like throughput, packet delivery ratio, round trip delay, collisions, protocol overhead time, network setup time etc. Netsim simulation of the heterogeneous communication network, selected from analysis of communication network simulation using multiple technologies, enables its performance validation. This work renders better comprehension in realization of Wide Area Measurement System for real time data collection and status update, Wide Area Control Systems for real time control and Advanced Metering Infrastructure for user integration transforming a microgrid to a smart microgrid.

Brief Reports on PIV Wide-Area Measurements and Instantaneous Velocity Evaluation for Wind Environmental Assessments

Brief Reports on PIV Wide-Area Measurements and Instantaneous Velocity Evaluation for Wind Environmental Assessments