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.

Chapter Contents:

• 4.1 Traditional visualization with SCADA
• 4.2 State monitoring with synchrophasors
• 4.3 Disturbance monitoring and identification using synchrophasors
• 4.3.1 Feature extraction
• 4.3.1.1 Discrete Fourier transform
• 4.3.1.2 Discrete wavelet transform
• 4.3.1.3 Principal component analysis
• 4.3.1.4 Shapelets
• 4.3.2 Classification
• 4.3.2.1 kNN classifier
• 4.3.2.2 SVM classifier
• 4.3.3 Case study: disturbance identification using PMU-generated disturbance files
• 4.3.3.1 Data
• 4.3.3.2 Selection of features and classifiers
• 4.3.3.3 Results
• 4.4 Use of synchrophasors for power system protection
• 4.4.1 Real-time constraints of power system protection
• 4.4.2 Suitability of PMU measurements for protection
• 4.4.3 Potential improvements in existing protection applications
• 4.4.4 Supervisory protection - potential use of synchrophasors to supervise local protection
• 4.4.5 Case study: synchrophasor-assisted out-of-step protection for generators
• 4.5 Conclusion
• References

Inspec keywords: phasor measurement; SCADA systems; power system security; power system protection

Other keywords: power system protection; power system security; supervisory protection; synchrophasor-assisted visualization; SCADA system; phasor measurement unit; supervisory control and data acquisition system

Subjects: Power system measurement and metering; Power system protection