Synchronized Phasor Measurements for Smart Grids
2: National Institute of Technology, Tiruchirappalli, Tiruchirappalli, Tamil Nadu, India
The use of advanced technologies has made it possible to transform the power grid to an intelligent smart grid with real time control and monitoring of the system. The development of Phasor Measurement Units (PMUs) and the resulting possibility of real time measurements has enabled different power system applications to enhance the stability, state estimation, load estimation, power network protection, Wide-Area Security Assessment and reliability of the power grid. Topics covered in this book include synchrophasors for improving the performance of power systems; optimal reliability criterion index (ORC) for optimal placement of phasor measurement Units (PMU); wide area measurement based power network protection; synchrophasor assisted visualization and protection of power systems; PMU measurements for enhanced power grid monitoring and protection; fault monitoring, detection and correction using synchrophasor measurements in modern power systems; transmission line fault detection, classification and localization in smart power grids; PMU-based vulnerability assessment of power systems; synchrophasor applications for load estimation and stability analysis; state estimation in the presence of synchronized measurement; PMU based wide-area security assessment. Synchronized Phasor Measurements for Smart Grids is essential reading for professional engineers and researchers, as well as graduate and PhD students, in power systems research.
Inspec keywords: power transmission lines; redundancy; power system measurement; power system stability; power system faults; power grids; fault diagnosis; power system security; power system protection; power system state estimation
Other keywords: PMU-based wide-area security assessment; wide-area measurement-based power network protection; power grid monitoring; state estimation; load estimation; transmission line fault detection; optimal redundancy criterion index; stability analysis
Subjects: Power system protection; Reliability; General topics, engineering mathematics and materials science; Power system measurement and metering; Power transmission lines and cables; Power system control
- Book DOI: 10.1049/PBPO097E
- Chapter DOI: 10.1049/PBPO097E
- ISBN: 9781785610110
- e-ISBN: 9781785610127
- Page count: 376
- Format: PDF
-
Front Matter
- + Show details - Hide details
-
p.
(1)
-
1 Synchrophasors for improving the performance of power system
- + Show details - Hide details
-
p.
1
–28
(28)
This chapter focuses on the introduction of synchrophasor technology and its practical use for enhancing real-time monitoring and control of the electric grid. Many real-life examples have been illustrated with the help of case studies. Realtime event analysis and low-frequency oscillation monitoring are the most basic applications of synchrophasor data which is possible with only a small number of PMUs deployed. Cause analysis of critical incidence and applying corrective action are some other areas where PMUs data is utilised for improvement of the grid performance.
-
2 An optimal redundancy criterion index (ORC) for optimal placement of phasor measurement units (PMU) for full observability of power grid
- + Show details - Hide details
-
p.
29
–58
(30)
The chapter provides an ORC for placement of synchrophasors. Test cases were evaluated for IEEE systems for scalability, and the criteria provide promising results for the placement problem.
-
3 Wide-area measurement-based power network protection
- + Show details - Hide details
-
p.
59
–97
(39)
Maloperation of power system protection schemes can result in escalation of a small disturbance to a severe situation in a power system. Events such as power swing, load encroachment, failure of components involved in the protection schemes leads to incorrect operation. This causes unwanted tripping or delay in clearing of faults from the system. This work attempts to use wide-area measurement data to support power system protection decisions in order to avoid maloperations. A combined feature-based decision for relay operation during power swing is developed to derive correct protection decision. Method for supporting relay decisions during stressed conditions such as power swing, voltage instability, and load encroachment by discriminating fault from these events is presented. Indices obtained from WAMS data in a power system are used for identifying malfunction of any element in a protection scheme. Further such informative data improve series compensated and three terminal line protections by applying adaptive settings for distance relays. The WAMS-based techniques enhance protection schemes by making them more reliable and speed up protection for power networks.
-
4 Synchrophasor-assisted visualization and protection of power systems
- + Show details - Hide details
-
p.
99
–122
(24)
Traditional visualization of power system is performed through supervisory control and data acquisition (SCADA) systems and state estimator algorithm. Though decades of development and implementation efforts coupled with modern computing resources have resulted in a robust and dependable visualization tool, the measurements fed to the SCADA system are scalar values and are not synchronized at a precise timestamp. Typically, a new set of measurements is available every 2-4 s, which is sufficient for steady-state analysis. With recent advances in sensing, it is possible to get measurements of better quality at a faster rate. Recent generation of phasor measurement units measure and transmit synchronized phasor values of voltages and currents at 60 fps. The purpose of this chapter is not to show how to assimilate these measurements with the current SCADA system, but to explore the possibility of creating another visualization layer independent of SCADA that can provide more insight in to real-time dynamic events taking place in power systems. A concept of supervisory protection is also explored to increase security of protection schemes by detecting relay misoperations. Results are presented from published research papers to facilitate critical evaluation of the feasibility of these concepts.
-
5 Using PMU measurements for enhanced power grid monitoring and protection
- + Show details - Hide details
-
p.
123
–146
(24)
This chapter discusses the opportunities that PMUs bring to enhance system monitoring and protection. Three topics are included: monitoring of power system operation, monitoring of power system model and wide-area fault location based on PMU measurements.
-
6 Fault monitoring, detection, and correction using synchrophasor measurements in modern power systems
- + Show details - Hide details
-
p.
147
–176
(30)
A collection of clustering algorithms was presented for grouping the PMU datasets into good and bad data. The results presented provide promising results for situational awareness for the next generation power grid.
-
7 Transmission line fault detection, classification, and localization in smart power grids using synchrophasor measurements
- + Show details - Hide details
-
p.
177
–210
(34)
Innovations in computational and communication technologies have been instrumental in the transition of conventional power grids to smart power grids (SPG) [1]. In SPG protection systems, one of the major research challenges is the development of real-time self-healing protection methodologies. A major constituent of selfhealing technology is transmission line fault monitoring [1,2]. Intelligent methods play a vital role to precisely detect, classify, and localize the transmission line faults occurring anywhere in the grid. Conventional fault monitoring methodologies for transmission lines are limited to specific transmission line configurations, and these methods have necessarily to be incorporated in all transmission lines. The transfer of information from transmission lines to system protection center (SPC) necessitates proper communication channels, leading to heavy computational and communication burden. SPG protection system tides over this burden. This chapter discusses methodologies for transmission line fault detection, classification, and localization in SPGs using wide-area phasor measurement unit (PMU) measurements, which can overcome the computational and communication burden.
-
8 PMU-based vulnerability assessment of power systems
- + Show details - Hide details
-
p.
211
–229
(19)
The proposed MLE method is validated for the assessment of one of the vulnerable patterns of power systems: transient rotor-angle instability. The main idea is to calculate MLE along the system dynamic trajectory in order to predict a loss of synchronism of power systems. Observability of PMU-based power system analysis is studied with a purpose of developing a method to quantify how well the available PMU measurements can be used to monitor dynamics of a power system. The research results in an innovative application of PMU data. Once an unstable power swing is captured and rotor-angle instability is predicted by the above method, self-healing actions, such as power system partitioning control.
-
9 Synchrophasor applications for load estimation and stability analysis
- + Show details - Hide details
-
p.
231
–275
(45)
The use of advanced real-time monitoring and control technologies have made it possible to transform the existing power grid into smart grid. With the development of phasor measurement units (PMUs) and the availability of real-time measurements, it has become possible to develop data-driven power system applications to enhance the stability and reliability of the power grid. The application of synchrophasor measurements for online assessment of voltage stability, real-time load parameter estimation, and transient stability prediction is presented in this chapter. The different voltage stability monitoring tools used in the industry are reviewed and analyzed. PMU-based distributed voltage stability monitoring technique is also presented in this chapter. The load modeling tool used in the industry and comprehensive research effort in load modeling is discussed in this chapter. The adaptive search-based recursive least-square algorithm is presented for improved online estimation of load parameters. The existing techniques available in the literature for transient stability assessment are reviewed in this chapter. Application of maximum Lyapunov exponent (MLE) for PMU-based online transient stability detection is discussed. The effectiveness of MLE-based method is demonstrated on real-time simulation of New England 39 bus system.
-
10 State estimation in the presence of synchronized measurement
- + Show details - Hide details
-
p.
277
–304
(28)
State estimation plays a critical role for the wide-area monitoring system at the control center. The power system network, geographically spread over a large area, is monitored and controlled using the measurements collected at regular intervals. A number of application functions are performed based on the estimated states of the system to ensure secure and reliable operation of the power system. The amplitude and angle of the voltage phasor at each bus constitute the states of the system. The measurements are collected from the field and telemetered to the control center, where they are processed, typically using standard-weighted least squares static state estimator, to estimate the states of the system.
-
11 PMU-based wide-area security assessment
- + Show details - Hide details
-
p.
305
–331
(27)
This chapter discusses data-mining-based catastrophe predictors using PMU-based WASI features. The study validates the performance of the black-box models such as SVM and RF through semitransparent data-mining models such as DT and transparent models such as DT_Fuzzy. It is observed from the extensive studies of the developed data-mining-based catastrophe predictors that while switching from the black box solutions to transparent and interpretable solutions, there is an unavoidable trade-off between accuracy, reliability, and security measures. The more transparent the predictor, the easier the implementation and maintenance by human actors. Overall, the fuzzy logic-based transparent solutions are preferred over black-box solutions to ease the implementation with improved robustness and enhance their suitability for auditing process, even sacrificing the predictive performance indices.
-
Back Matter
- + Show details - Hide details
-
p.
(1)