System Restoration

Question 1

Dynamic Reserves

Answer 1

1. 50% OR less allowed to be LOAD SHED.
2. MUST be sufficient to support frequency deviations due to loss of largest contingency.
3. Load pickup factors: max load generation can take without frequency decline:
   a. 5% fossil
   b. 15% hydro
   c. 25% combustion turbines

Question 2

Synch/Spinning

Answer 2

1. Load shed counts as synch reserves ONLY during restoration.
   Frequency:
   a. 59.75HZ - 61HZ
   b. Regulation to maintain frequency is 2% of area Load.
   c. Shedding approximately 6% of load to raise frequency 1HZ.

Question 3

Priorities during restoration

Answer 3

a. Cranking power to hot units that can be RTS
b. providing AUX to nuclear plants
c. Critical loads
d. Non-critical loads
e. Communications between GO and TSO

Question 4

Voltage control

Answer 4

Capacitors:
a. generates VARS
b. removed from service until approx. 40% load has been re-energized.

Reactors:
a. Reduces system voltages.
b. Absorbs VARS.

Goal is to maintain approx. 90% to 105%

Question 5

Manual Control

Answer 5

a. When there is insufficient data for automatic control
b. PJM replaces frequency control

Question 6

Flat frequency control

Answer 6

a. Initiated when ACE signal is developed using frequency value in interconnected area.
b. used when PJM BA is islanding, or isolated from eastern interconnection.
c. frequency bias is 1% of interconnected area’s load

Flat Frequency Control utilizes only power system frequency
as the controlling parameter. This mode of control only responds to frequency deviations
and does not adjust operations for any interconnection tie line schedule deviations. This
mode is applicable only to those instances when the PJM Balancing Authority Area
becomes isolated from the Eastern Interconnection.

Question 7

Tie Line bias control

Answer 7

a. Develops ACE signal when tie lines in service
b. Normal control mode.

Question 8

Black Start Units

Answer 8

a. TOs manage and deploy black start units.
b. TO review annual restoration plan.
c. TOs have authority/responsibility for restoration
d. 2 black starts per TO zone

Question 9

General Guidelines

Answer 9

approx. 1.7MVAR/Mile on 500 KILOVOLT lines

600 MW connected at 230 Kilovolt lines / higher

Question 10

Level one cross zonal coordination

Answer 10

1. black start unit supplies outside zone
2. eliminates black start shortage in a given zone

Question 11

Level two cross zonal coordination

Answer 11

1. Single black start serving load pockets in multiple TO Zones
2. example: 1 BS unit supplies its own geographical zone and another.

Question 12

Level three cross zonal coordination

Answer 12

a. combines multiple TO restoration plans into a newly defined region.
b. Example: Merging 2 or more TO zones or create a new larger region with 1 plan

Question 13

Black Start Criteria & Requirements

Answer 13

a. 110% critical load requirement
b. 2 black start units per zone redundancy
c. maintain fuel for 16 hour routine
d. less than 3 hour start time (breaker close to dead bus)
e. Equipment tested manually

Question 14

Flat tie line control

Answer 14

Flat tie Line Control utilizes only interconnection tie line flow as
the controlling parameter. This mode of control only responds to net tie flow deviations
and does not adjust operation for any frequency deviations. This mode is limited to
special circumstances when the PJM Balancing Authority desires to maintain a given
net interchange flow, and the power system frequency is stable and being controlled by
other Balancing Areas