Dynamic Performance Requirements for Phasor Meausrement Units 2010 February NAPSI Meeting Dmitry Kosterev Transmission Planning Bonneville Power Administration dnkosterev@bpa.gov Slide 1
BPA Plans for Synchro-Phasor Infrastructure 120+ PMUs planned to be installed at 70+ sites Additional PMUs will be installed on Wind Power Plants PMUs will be streaming data continuously to both control centers Control PMUs will be stand-alone Used for wide-area control and situational awareness applications Data PMUs may include several functions Slide 2
Planned Applications of Synchro-Phasor Data APPLICATIONS DRIVE REQUIREMENTS Engineering applications Disturbance analysis, performance base-lining System model validation Inter-area oscillation analysis Situational Awareness for Operators Trending tools, phase angle alarms, etc Mode Meter and Oscillation Alarms Wide-area stability controls Response-based fast reactive switching Continuous feedback power modulation Slide 3
PMU Dynamic Performance and Applications Phasor 120 110 100 90 80 70 60 System Protection and Control: - large changes - very fast response 200 150 Point of Wave Data: - disturbance analysis 50 0 10 20 30 40 50 60 100 50 0 115.15 115.1 115.05 115 114.95 114.9 114.85 0 5 10 15 20 25 30 35 40-50 -100-150 Oscillation Damping: - small signals - high precision -200 44.98 44.99 45 45.01 45.02 45.03 45.04 45.05 45.06 45.07 Slide 4
PMU Dynamic Performance and Applications Various PMU applications may have different data requirements Oscillation damping Small signal analysis good filtering and high signal quality are required, response of up to 3 cycles is acceptable System protection and wide-area controls Detect large changes fast, sub-cycle response Engineering analysis Looking for all of the above May be also interested in point-of-wave data (particularly loads, SVCs, HVDC, wind power plants, other controllers) Slide 5
PMUs for Dynamic Performance Analysis and Control Oscillation damping controls and mode meter are one of the most demanding PMU applications PMU filtering must meet somewhat conflicting requirements: Must have fast response and wide bandwidth (not as fast as protection, 3 cycle response is acceptable) Must reject out-of-band signals Dr John Hauer initially developed the PMU filtering standard for BPA and WECC Recently, Dan Trudnowski expanded the requirements and investigated the feasibility of designing PMU filter to meet these requirements Slide 6
It is not a pure 60 Hz wave-form Inter-area oscillations = 0.1 0.7 Hz Local generator oscillations = 0.5 2.0 Hz Wind turbine-generator torsional = 1.5 2.0 Hz HVDC control modes ~ 5 Hz, 30Hz? Exciter control modes ~ 5 Hz Steam turbine torsional ~5Hz, 10Hz, 15Hz, 30 Hz, 50 Hz Harmonics Slide 7
Gain Requirements 20 10 Pass band > 5 Hz Gain, G (db) 0-10 -20-30 -40 Pattern continues to infinity -50-60 Transition band 2 Hz width 4 Hz width -70 Nyquist (f S2 /2) -80 0 20 40 60 80 100 120 140 Frequency (Hz) Slide 8 8
Phase Requirements 20 10 Phase starts at 0 Phase, G (degrees) 0-10 -20-30 -40 Phase < 20 for freq < 2 Hz -50-60 -70 Near Linear phase in pass band -80 0 1 2 3 4 5 Frequency (Hz) Slide 9 9
Where we are: Dynamic performance requirements are developed, and the feasibility of meeting these requirements is confirmed paper by Dan Trudnowski Lab test procedures are developed by Tony Faris at BPA BPA is currently testing PMUs from 11 vendors for dynamic performance Tony Faris We would like to make a recommendation on vendor selection by July 2010 Slide 10 10
What we would like to see in a PMU 3-phase analog data from PTs & CTs A/D Dynamic Performance Filter Protection and Control Filter Streaming phasors for Dynamic Performance applications at 60 sps Streaming phasors for Protection and Control applications at 120 sps PMU Point of Wave digital data at = or > 1920 sps, stored locally Slide 11 11
Additional Slides Slide 12
Technical References Dan Trundowski, Recommended PMU Dynamic Requirements for Small-Signal Applications, October 2009 Detailed technical requirements Examples of the filters that meet dynamic performance requirements Available at NASPI web-site For in-depth analysis, please refer to the library of papers by John Hauer, available from BPA and PNNL Slide 13
Dynamic Performance Requirements Summary Gain REQUIRED: The gain does not exceed -40 db at frequencies above the Nyquist frequency continuing to infinity. REQUIRED: The gain does not exceed -60 db at frequencies that are harmonics of 60 Hz. The notch at 60 Hz is 2 Hz with linearly increasing notches for higher harmonics. REQUIRED: The pass band gain has no ripple and is within 0.5 db out to 1.5 Hz. REQUIRED: The corner frequency (-3 db) must be greater than or equal to 5 Hz. Phase REQUIRED: The phase start 0 at DC. REQUIRED: The phase must be bound by +20 for all frequencies less than or equal to 2 Hz. DESIRED: The phase is as linear as possible in the pass band. Step Response REQUIRED: The 90% rise time occurs within 50 msec. DESIRED: The percent overshoot does not exceed 10%. REQUIRED: The 2% settling time is less than or equal to 3Tp. This includes any delay in the time tag Slide 14 14
Signal Quality Reliable performance is required for system frequency excursions ranging from 58 Hz to 62 Hz. Resolution of the analog-to-digital (A/D) conversion process must be 16 bits or higher. Scaling of signals entering the A/D conversion should assure that 12-14 bits are actively used to represent them. Signals for which this scaling may overload the A/D during large transients may be recorded on two channels, in which one has less resolution but a greater dynamic range. Measurement noise must be within the normal limits of modern instrument technology. Slide 15
Overall PMU Evaluation Determination of PMU performance is based upon integrated use of laboratory tests, model simulations, and comparative measurements under field operating conditions [A]. Laboratory tests are necessary but not sufficient. PMU documentation must permit overall quality of instrument processing to be assessed acquired records to be compensated for known attenuation and delays [A] Evaluating the Dynamic Performance of Phasor Measurement Units: Experience in the Western Power System, J. F. Hauer, Ken Martin, and Harry Lee. Interim Report of the WECC Disturbance Monitoring Work Group, August 5, 2005. (Available at ftp.bpa.gov/pub/wams%20information/) Slide 16