Quiz: Workshop 01

Synchrophasors can provide a dynamic view of a power system because of the;

• time synchronized measurements provided with time stamps

• faster reporting rates compared to SCADA measurements

• measurement of phase angles

• faster communication networks used

Synchrophasors can provide an accurate snapshot of a power system because of the;

• time synchronized measurements provided with time stamps

• faster reporting rates compared to SCADA measurements

• faster communication networks used

• none of the above

Standard synchrophasor reporting rates for a 50Hz system are;

• 60, 30, 15, 10 fps

• 50, 25, 12.5, 10 fps

• 50, 25, 10 fps

• 150, 50, 25, 10 fps

P-class PMUs are used for;

• Only for protection purposes

• Only for measurement purposes

• Applications that require high measurement accuracy

• Applications that require faster measurement response

M-class PMUs are used for;

• Only for protection purposes

• Only for measurement purposes

• Applications that require high measurement accuracy

• Applications that require faster measurement response

Functions of a Phasor Data Concentrator (PDC) do NOT include;   

• Estimating time synchronized phasors from sample values streamed over network

• Aligning phasor measurements based on time tags

• Preparing outputs aggregating the measurements of multiple PMUs

• Flagging missing data

Phase angle of a synchrophasor is zero when;    

• The zero crossing of a cosine signal coincides with the beginning of UTC second

• The peak of a cosine signal synchronized with the local device clock

• The peak of a sine signal coincides with the beginning of UTC second

• The peak of a cosine signal coincides with the beginning of UTC second

Phase angle reported with consecutive synchrophasor measurements can appear to change with time;   

• when the system frequency deviates from the nominal value

• when the phase angle is changing due to changes in the power system   

• when the GPS clock connected to PMU is not stable due to a problem in antenna

• all of the above 

DFT based phasor estimation method   

• works perfectly when the system frequency deviates from the nominal value

• works perfectly when the system frequency is exactly equal to the nominal value  

• shows oscillations in the estimated magnitude and phase angle when the system frequency is exactly equal to the nominal value   

• both (b) and (c) are correct

Format of the time stamp provided with synchrophasor measurements include;

• Second of century and the faction of second

• Year, month, date, hour, second

• Year, month, date, hour, second, millisecond

• Second of century and millisecond