and Trend for Smart Grid Application of Phasor Measurement Units and Wide Area Monitoring System of EGAT’s Network and Trend for Smart Grid Suphot Jitlikhit Head in, Power System Analysis Section 1 Control & Protection Division Electricity Generating Authority of Thailand Smart Grid and Diagnostics December 8, 2010 EGAT, Thailand

Contents WAMS & PMU history in EGAT’s network Phasor vs. SCADA Comparison SCADA vs. PMU Measurement Example for Real time Application Benefits of using PMU in EGAT &Trend to Smart Grid Conclusion WAMS & PMU

Wide Area Monitoring (WAMS) : use GPS Satellite PMU Wide Area Monitoring System use a GPS satellite signal to time-synchronize from phasor measurement units (PMUs) at important nodes in the power system, send real-time phasor (angle and magnitude) data to a Control Centre. The acquired phasor data provides dynamic information on power systems, which helps operators to initiate corrective actions to enhance the power system reliability. WAMS & PMU

Wide Area Monitoring (WAMS) : System Configuration GPS synchronized current and voltage phasor measurement. High precision data acquisition Time resolution: < 10–6 s Measurement quality: 0.1% of U and I and Angle accuracy of < +/- 0.05% EGAT Installation of PMUs at critical nodes in Power Systems. WAMS & PMU

Wide Area Monitoring (WAMS) : Project in 2005 EGAT installation Wide Area Monitoring (WAMS) Inter-area oscillation on the tie transmission line between the Central system and the Southern system is one of the important problems which lead to reduce stability and security of the transmission system. To prevent system from inter-area oscillation, Wide Area Monitoring System (WAMS) was installed at the Central system and the Southern system in 2005 to monitor the stability of this power transmission network. Bottleneck in transmission corridor: Limit due to concerns about power oscillation , the origin, amplitude, frequency, usual duration and damping of oscillation are not know WAMS & PMU

Central-South power corridor Wide Area Monitoring (WAMS) : Power Oscillation Monitoring Bang Saphan Central-South power corridor Surat Thani WAMS & PMU

Wide Area Monitoring (WAMS) : PMU Installation EGAT installation Wide Area Monitoring (WAMS) Phasors Monitoring Units (PMUs) are installed at Bang Saphan and Surathani Substation and use a GPS satellite signal to time-synchronize voltage and current readings as they are taken from both substations. Data can be streamed into a Control Center from far-flung points in the grid, where it is evaluated to give grid operators a precise picture of what is happening in their system, online. They can also finally see what is happening beyond their own control area – an advance over traditional monitoring and protection methods. WAMS Benefit: Detect of oscillation, Assessment of power system damping, Oscillation Monitoring, Increase power transfer at defined security, and Early warning to avoid power system collapse. WAMS & PMU

Wide Area Monitoring (WAMS) : Schematic Diagram WAMS & PMU

Wide Area Monitoring (WAMS) : Project in 2010 The project has upgraded from the existing of Digital Fault Recorder (DFR), totally 6 sites and 14 PMUs installed. This is as the pilot project to test the function of PMU on DFR platform. Phasor Data Concentrator (PDC) and its software application has been installed in the server and its display available at the operator console for visualization. This project has only used for monitoring purpose and observe the system in broader scale.. WAMS & PMU

Wide Area Monitoring (WAMS) : Phasor vs. SCADA Comparison WAMS & PMU

Wide Area Monitoring (WAMS) : SCADA vs. PMU Measurement PMU is the higher time-resolution providing about power system dynamics in comparison with SCADA/EMS WAMS & PMU

Wide Area Monitoring (WAMS) : Example for Real time Application Phase Angle Monitoring Voltage Stability Monitoring Power Oscillation Monitoring WAMS & PMU

WAMS Application Example: Phase Angle Monitoring Benefits: Provide operator with real time information about voltage phase angle deviation, Improve voltage control, improve system stability, security and reliability , and operate safety carrying components closer to their limit. WAMS & PMU

WAMS Application Example: Voltage Stability Monitoring Early warning Emergency alarm Normal Operation Benefit: Early warning against voltage collapses, Immediate stop of cascading effects, and Protection against uprising voltage instabilities. 14 PMU & WAMS WAMS & PMU

WAMS Application Example: Power Oscillation Monitoring EGAT EGAT System Status: Normal, Warning and Alarm Wide Area Monitoring WAMS Benefit: Detection of oscillation, Assessment of power system damping, Increase power transfer at defined security, and Early warning to avoid power system collapse. WAMS & PMU

Benefit of Using PMU in EGAT & Trend for Smart Grid Goal & Benefits Real time monitoring Post-disturbance analysis Adaptive protection Power system restoration Source: Dr. Luigi Vanfretti, KTH Sweden WAMS & PMU

Benefit of Using PMU in EGAT &Trend Smart Grid: Real time monitoring Goal To provide operators with real time knowledge of system conditions Benefits of using PMU Improve calculation for real time path flow and optimal dispatch Provide actual limits of the system instead of the conservative ones from offline calculations 17 WAMS & PMU

Easier to understand sequence of events when using Benefit of Using PMU in EGAT & Trend for Smart Grid: Post Disturbance Analysis Goal To reconstruct the sequence of events after disturbance has occurred Benefits of using PMU Easier to understand sequence of events when using synchronized data from PMU WAMS & PMU

Benefit of Using PMU in EGAT&Trend for Smart Grid: Adaptive Protection Goal Adapt protection to be appropriate with system condition Benefits of using PMU Improved backup protection Adaptive protection setting to avoid cascading outage WAMS & PMU

Goal Benefits of using PMU Benefit of Using PMU in EGAT&Trend for Smart Grid: Power System Restoration Goal Assist system operator during restoration with data from PMU Benefits of using PMU System operator have more confidence during restoration Reduce chance of recurrence of system outage Reduce time needed for a system restoration WAMS & PMU

Benefit of Using PMU in EGAT&Trend for Smart Grid: Smart Transmission Grid WAMS & PMU

EGAT has installed WAMS & PMU since 2005, for monitoring Conclusion EGAT has installed WAMS & PMU since 2005, for monitoring and resolution of power oscillation problem between Central and Southern region. In 2010, more project has installed for visualization of power system in broader scale. The capabilities of PMU for high precision, speed of response and GPS time synchronization make PMU very appropriate for wide area monitoring for protection and control. An Advanced early warning technology for power grids that helps operators to ensure grid reliability by detecting and counteracting the first signs of grid instability. Trend for the Smart Grid for the future. WAMS & PMU