1. Present a clean solution (written document) of the coordination problem shown in the figure. Calculate the TD and the instantaneous elements of all phase relays(from relay 1 to relay 10 only). Indicate where a short-time-definite-time element is necessary and calculate its settings. Use a coordination time interval of 0.3seconds. Show all your results in TCC sketches. Use 6-INT in 0.1 seconds for the transformer in rush. All relays have the following curve: t=T D \cdot\left(\frac{5.95}{M^{2}-1}+0.18\right) 2. Plot at formal TCC (not a sketch) relays 12, 10 and 5 and transformer damage curve (use the curve given in class). 3. Write a program to calculate the TD of a relay upstream given the data of the relay downstream (optional for 431 students). 4. Check the given three-phase short circuit currents (optional for 431 students).

Fig: 1

Fig: 2

Fig: 3

Fig: 4

Fig: 5

Fig: 6

Fig: 7