Reference no: EM132508328

EEPW 4180 Numerical Methods in Power - Shinas College of Technology

Question 1: [a]The whole power system operates at 200MVA base and the fault is occurred due to failure of insulation at bus number2 between phase "A" and "B". The fault current flows to the ground with the effect of fault impedance j0.03. Taking into consideration of pre-fault voltage =1.07p.u., find all the phase currents at faulty bus. Due to this fault current there will change the sequence current flowing between the bus 3 & bus -4, find this symmetrical current.
[B] If the line L34 has a positive sequence impedance is (3+j3), Calculate the positive sequence voltage drop across the line L34.
[c] What is the maximum current that the Insulation can withstand without out causing the fault in faulty bus? Justify your answer.

Question 2:[a] A consumer complaints against the power failure to the concerned authority. The authority pass the information to an engineer and he identified that the short circuit occurred at the bus number-6 , and also he identifies the zero , negative sequence voltage are not affected the system. As an engineer find all the symmetrical and phase potential difference between the bus -2 &bus-4 and also between bus-5 & bus-6 during fault condition ,by assuming short circuit current does not have the effect of fault reactance in the short circuit path.[ Take pre-fault voltage as 1.08p.u.].
[b] Based on the calculation write the conclusion on the fault and justify your answer.

Question 3:[a] Write the appropriate numerical method equation for the whole power system operating under steady state conditions with 100MVA base, where the susceptance part of admittance is very small and product of conductance and sine angle of voltage angles is approximately zero in the power system. Perform the load flow Analysis of the systems up to first iteration using relevant numerical method while the bus number 2,4 and 5 are isolated.

[b] By considering first iteration voltage magnitude and voltage angle values, Calculate the active & reactive powers at slack bus as well as reactive power at bus-6 without considering the bus number 2,4 and 5. What is significance of losses in the power system and how it is considered in the load flow analysis? Justify your answer.

Question 4: The Table consists of specification and symmetrical line data of the power system. Due to the wind the magnitude of line short circuit current flowing through the two lines are same in bus number- 5 with short circuit path impedance j0.05. With pre-fault voltage of 1.04p.u., Find all the sequence currents flowing through the circuit breaker which is connected between bus-2&bus- 4 and all the sequence currents that flow though the conductor connected between bus-1 & bus-6. What could be the ratings of fuses to be placed at bus number-5 to avoid the short circuit ? Justify your answer.

Attachment:- Shinas College of Technology.rar