ch R Figure P1 Problem P1 (10 points): Consider an 800 A circuit, 25.0 kV, 2 miles long, as it is illustrated in Figure P1. The equivalent source impedance (on a 100 MVA basis) is: Z₁ = Z₂ = j0.15 pu, zo j0.18 pu The CT is rated 1200:5A. The impedance of the circuit is: Z₁ = Z₂ = j0.70 ohms/mile, zo = j2.10 ohms/mile A time overcurrent relay is located at the indicated location. Assume that the relay is a numerical relay that has instantaneous overcurrent protection as well as time-overcurrent protection with the following selections: Moderately Inverse: to = Very Inverse: to = 19.61 12² −1 Extremely Inverse: to = 0.0515 10.02-1 r ta +(0.114) ta 2 miles ta +(0.491)ta 28.2 1²-1²d + (0.1217) d -ta r Where to is the time dial that can be set from 0.1 to 15.0 (any numerical value in this interval, it does not have to be discrete values). The relay settings are: pickup current=6A, time dial=1.0. Compute the time to trip for: 1. A line to line fault at the middle of the distribution line. 2. A single line to ground fault at the middle of the distribution line. 3. A line to line fault at the end of the distribution line. 4. A single line to ground fault at the end of the distribution line.