PRACTICE SOLUTIONS GRADED A+
● Balancing Area A notices that the Interconnection frequency is 59.94
Hz and their ACE is 0. Which of the following could be the cause of this
reading?
a) A net under-generation in Balancing Area A
b) A net under-generation in the Interconnection
c) A loss of load in Balancing Area A
d) A loss of load in the Interconnection. Answer: b) A net under-
generation in the Interconnection
● What is the penalty for a Balancing Authority violating the
Disturbance Control Standard?
a) Must carry additional Contingency Reserve
b) Must develop a correction action plan
c) Must re-evaluate and change its Frequency Bias Setting
d) Must increase its Regulating Reserve. Answer: a) Must carry
additional Contingency Reserve
, ● Your ACE is a large negative value and system frequency is 59.80 Hz.
Your AGC system is pulsing your units down. What should you do?
a) Place AGC in flat frequency control
b) Place AGC in flat tie line control
c) Suspend AGC and investigate
d) Do nothing as this is normal. Answer: c) Suspend AGC and
investigate
● When two identical generating units are operated in parallel on
governor control, and on machine has a 5% droop and the other has a
10% droop, the unit with the greater (10%) governor droop will:
a) Respond less to frequency deviations
b) Respond more to frequency deviations
c) Respond the same to frequency deviations
d) Not adjust for frequency changes. Answer: a) Respond less to
frequency deviations
● On a radial transmission system a generator has a capacity of 600
MWs. The Droop characteristic is at 5% and the generator is currently
loaded at 300 MWs. If frequency suddenly drops to 59.3 Hz, what would
be the total generator output?