HSI Final Test Questions and
Answers 2025
The initial response to a frequency deviation is due to which of the following
1. Load / frequency response
2. AGC
3. Governor action
4. Interchange schedules
•3 and 4
•1 and 2
•2 and 3
✓ •1 and 3 •1 and 3
EMS and AGC have failed at 12:25 and generation must be controlled
manually. The operator calculates ACE to be +25 MWs. Load is expected to
increase 100 MWs, and imports will increase by 75 MWs at the top of the hour.
What should the operator do?
•Maintain current generation level
Master01 | October, 2024/2025 | Latest update
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•Decrease generation by 25 MWs
•Decrease generation by 50 MWs
✓ •Increase generation by 25 MW •Decrease generation by 25 MWs
How is the Frequency Response Measure (FRM) of a Balancing Authority
determined?
•lt is the average of the BA's frequency response for all the frequency
deviations of the previous year
•lt is the change in the BA's Net Interchange Actual for the largest frequency
deviation during the previous year
•lt is the previous year's Control Performance Standard 1 ( CPS1 ) score
✓ •It is the median of the BA's frequency response for the frequency
deviation events identified by NERC for the previous year •It is the
median of the BA's frequency response for the frequency deviation
events identified by NERC for the previous year
Sufficient Operating Reserve is defined as the capacity required to meet
what?
•DOE specifications
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•CPS and DCS
•CPS 1 & 2 only
✓ •Capacity Standard •CPS and DCS
In your Interconnection , a generator tripped that was large enough to
reduce the frequency from 60.00 Hz to 59.94 Hz . Your Balancing Authority's
Frequency Bias is -200 MW / 0.1 Hz . How many MW would your system initially
contribute to frequency support?
•120 MW
•80 MW
•100 MW
✓ •200 MW •120 MW
Interconnection frequency is 59.80 Hz . Your ACE is a large negative value
and your AGC is pulsing your units down . What should you do
•Leave AGC in operation but investigate
•Place AGC in constant frequency control
•Place AGC in flat tie line control
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✓ •Suspend AGC and investigate •Suspend AGC and investigate
When a Balancing Authority's ACE value is the same sign as the frequency
deviation , which NERC control performance score is affected negatively
•DCS
•CPS 1
•TEC
✓ •BAAL •CPS 1
Correct Of the following , which control system would be affected by a
difference in Net Actual Interchange and Net Scheduled Interchange
•Reactive Control
•Turbine Governor Control
•Automatic Generation Control
✓ •Automatic Voltage Regulator •Automatic Generation Control
Balancing Authority A is currently reading a system frequency of 59.98 Hz . Its
Net Actual Interchange is +100 MW and its Net Scheduled Interchange is +100
Master01 | October, 2024/2025 | Latest update
Answers 2025
The initial response to a frequency deviation is due to which of the following
1. Load / frequency response
2. AGC
3. Governor action
4. Interchange schedules
•3 and 4
•1 and 2
•2 and 3
✓ •1 and 3 •1 and 3
EMS and AGC have failed at 12:25 and generation must be controlled
manually. The operator calculates ACE to be +25 MWs. Load is expected to
increase 100 MWs, and imports will increase by 75 MWs at the top of the hour.
What should the operator do?
•Maintain current generation level
Master01 | October, 2024/2025 | Latest update
, 1 | P a g e | © copyright 2024/2025 | Grade A+
•Decrease generation by 25 MWs
•Decrease generation by 50 MWs
✓ •Increase generation by 25 MW •Decrease generation by 25 MWs
How is the Frequency Response Measure (FRM) of a Balancing Authority
determined?
•lt is the average of the BA's frequency response for all the frequency
deviations of the previous year
•lt is the change in the BA's Net Interchange Actual for the largest frequency
deviation during the previous year
•lt is the previous year's Control Performance Standard 1 ( CPS1 ) score
✓ •It is the median of the BA's frequency response for the frequency
deviation events identified by NERC for the previous year •It is the
median of the BA's frequency response for the frequency deviation
events identified by NERC for the previous year
Sufficient Operating Reserve is defined as the capacity required to meet
what?
•DOE specifications
Master01 | October, 2024/2025 | Latest update
, 1 | P a g e | © copyright 2024/2025 | Grade A+
•CPS and DCS
•CPS 1 & 2 only
✓ •Capacity Standard •CPS and DCS
In your Interconnection , a generator tripped that was large enough to
reduce the frequency from 60.00 Hz to 59.94 Hz . Your Balancing Authority's
Frequency Bias is -200 MW / 0.1 Hz . How many MW would your system initially
contribute to frequency support?
•120 MW
•80 MW
•100 MW
✓ •200 MW •120 MW
Interconnection frequency is 59.80 Hz . Your ACE is a large negative value
and your AGC is pulsing your units down . What should you do
•Leave AGC in operation but investigate
•Place AGC in constant frequency control
•Place AGC in flat tie line control
Master01 | October, 2024/2025 | Latest update
, 1 | P a g e | © copyright 2024/2025 | Grade A+
✓ •Suspend AGC and investigate •Suspend AGC and investigate
When a Balancing Authority's ACE value is the same sign as the frequency
deviation , which NERC control performance score is affected negatively
•DCS
•CPS 1
•TEC
✓ •BAAL •CPS 1
Correct Of the following , which control system would be affected by a
difference in Net Actual Interchange and Net Scheduled Interchange
•Reactive Control
•Turbine Governor Control
•Automatic Generation Control
✓ •Automatic Voltage Regulator •Automatic Generation Control
Balancing Authority A is currently reading a system frequency of 59.98 Hz . Its
Net Actual Interchange is +100 MW and its Net Scheduled Interchange is +100
Master01 | October, 2024/2025 | Latest update
