HW06 EE6560 Power System Protection 1
Do 12.47kV distribution protection and coordination. The HW06 ASPEN model, coordination summary table,
and an excerpt from Ameren PS-50 are on Canvas as your starting point. The model already has the network
model, a Recloser with settings, Grocer customer 480V breaker settings, and Ameren 14G standard 12.47kV
feeder device 51 and 51N settings. You are allowed to change the 12kV 51 and 51N settings and the Recloser
type & size though you must explain your reasoning.
1. Please specify fuses at Point M, Grocer high side (HS), and Point P. Refer to completed coordination
table and TCC to explain. (30 points)
2. Choose the 34.5/12.47kV substation main breaker device 51 and 51N types, CT ratio, and specify
settings. Refer to completed coordination table and TCC to explain. (50 points)
3. Simulate the required faults and complete the coordination table; (you may need separate phase and
ground coordination tables.) (40 points)
4. Provide PDF of Time-Current Curves (TCC) for (30 points)
a. Grocer transformer damage curve, fuse, and LS breaker settings
b. Feeder phase protection
c. Feeder ground protection
5. Criteria:
a. In general our minimum Detection Margin = 1.5 (with 2 preferred), and minimum Load Margin
is 1.15, and substation relay minimum Coordinating Time Interval (CTI) = 0.3 seconds.
b. PS-50 provides feeder protection and coordination criteria.
c. Strive to minimize total clearing times.
Paul Nauert 3/6/2023