3. Determine the subtransient fault current in per-unit and in kA during a bolted throo-phase fault at the bus selected in Problem 2.

Question 3.1 At 11:00 hours there is a difference of 20V between the voltage measured across the loads in the home network and the voltage measured at the substation. Estimate the value of the underground cable resistance Rc that would cause such a voltage difference. Question 3.2 Assume that the value of the underground cable resistance is equal to Rc = 50. Calculate the peak power loss in the underground cable during the 24-hour time period. Question 3.3 Assume that the value of the underground cable resistance is equal to Rc = 5 Q. Calculate the total current flowing from the home network to the substation if all the available appliances are switched on (ignore the time schedule) and the Solar Panels are generating current that is equal to 10 A. Use the sign to indicate whether the (positive) current is flowing from the home network to the substation (in which case you should use positive '+' sign), or whether the (positive) current is flowing from the substation to the home network (in which case you should use negative '-' sign).

Question An AC source at 60 Hz is supplying 25 kW to a load at a lagging power factor of 0.5. If the rms voltage of the supply is 4 kV what capacitance is required to be hooked up in parallel to the load so that the power factor is raised to 0.8 lagging?

Solve for transmission line parameters (R,X) in p.u on all 3 lines (12, 23, 31). Show works in detail. Can handwriting or typed.

Question 4 An ideal transformer is rated to deliver 430 kVA at 220 V (rms) to a customer, as shown in the figure. How much current, in kA, can the transformer supply to the customer? Question 5 An ideal transformer is rated to deliver 422 kVA at 220 V (rms) to a customer, as shown in the figure. If the customer's load is purely resistive, what is the maximum power, in kW, that the customer can receive? Question 6 An ideal transformer is rated to deliver 421 kVA at 220 V (rms) to a customer, as shown in the figure. If the customer's power factor is 0.9 lagging, what is the maximum usable power the customer can receive? Question 7 An ideal transformer is rated to deliver 438 kVA at 220 V (rms) to a customer, as shown in the figure. If the customer requires 341 kW to operate, what is the minimum power factor with the given size transformer?

Question 1 For the circuit shown in the figure, assume that V = 67 20 Vrms, Rg = 2 , N = 5, and R₁ = 16. Assume an ideal transformer. Find the amplitude of equivalent load resistance seen by the voltage source. Round off your answer to two decimal places. Note: Z = a + jb then the amplitude of Z is √a² +6² Question 2 For the circuit shown in the figure, assume that V = 68 20 V rms, Rg = 22, N = 5, and R₁ = 19. Assume an ideal transformer. Find the power Psource (KW) supplied by the voltage source. Round off your answer to two decimal places and provide your answer in Kilowatts. Question 3 For the circuit shown in the figure, assume that V₂ = 63 20 V rms, R = 12, N= 3, and Ro = 172. Assume an ideal transformer. Find the power Pload (kW) consumed by Ro Round off your answer to two decimal places and provide your answer in Kilowatts.

Problem-2 [60 Points] A junior engineer for Evergy has been given the assignment to design a new 4.16 kV, three-phase feeder that will have the following characteristics: The total length of feeder = 5000 ft Load: Ten 500 kVA (three-phase), 0.9 lagging power spaced every 500 ft with the first load 500 ft from the substation Voltage drop: Not to exceed 5% from the sub to the last load Figure. 2 illustrates the new feeder. The engineer has decided to use 336,400 26/7 ACSR (Linnet) conductors constructed on 45 ft poles with 8 ft crossarms. The spacings of the conductors on the crossarms are 2.5, 4.5, and 7.0 ft. a. Determine the percent voltage drop to the last load point and the total three- phase power loss for the feeder as shown in Figure. 2 b. Lump the total feeder load at the midpoint of the feeder and compute the percent voltage drop to the end of the feeder. c. Use the "exact lumped load model and compute the percent voltage drop to the end of the line and the total three-phase power loss down the line.

3. During a phase "a" single line-to-ground fault, the phase angle on phase "a" voltages is always zero. Explain why we would expect this behavior for a bolted SLG fault.

Question-1 Draw the per phase, per unit equivalent circuit for the system shown in Figure. 1. The system MVA base is 100 MVA and the voltage base is 220 kV on the high voltage transmission line section. The equipment nameplate data is given below: G1: 50 MVA, 13.8 kV, X = 15% G2: 25 MVA, 14.4 kV, X = 15% T1: 60 MVA, 13.8: 230 kV, X = 10% T2: 30 MVA, 230: 13.8 kV, X = 10% Line 1: 10+j100 Ohm Line 2: 5+j50 Ohm Line 3: 5+j50 Ohm Load: 75 MVA, 0.9pf lagging

Assignment The noise on HVIL is causing concerns and you need to come up with some ideas on how to solve this. Note from project manager: If necessary, please make a test plan on what needs to be tested or measured and if possible, write down some hypothesises about what could be the problem. Note from HW manager: Please analyse the circuit and try to find potential issues to be tested in the lab as this is much quicker than going for a field test far away. Also, why is there a big difference in HVIL_OK signal between driving and charging when it is not reflected in the HVIL current? Treat this assignment confidentially. You are free to use the internet and search for information, but you are not allowed to share this document or any information in this document with anyone. Good luck!