SYMMETRICAL FAULT CALCULATIONS – PART – 16 – CALCULATION OF POST FAULT CURRENTS AND VOLTAGES & ONE PROBLEM

PROBLEM

For the circuit shown in the figure.

Draw the reactance diagram. Calculate the total fault current in the generator and motor under the fault condition and also calculate the generator and motor post-fault current.

SYMMETRICAL FAULT CALCULATIONS – PART – 15 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM

For the system shown in the figure. (1) Draw the reactance diagram (2) calculate the terminal voltage and (3) If the fault occurs at bus 4 calculate the fault current.

SYMMETRICAL FAULT CALCULATIONS – PART – 14 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM

For the network shown in the figure. If the fault occurs on the bus two, calculate the per-unit fault current when Xf = 0 and Xf = j0.1 and also calculate the current contribution of generator and motor.

SYMMETRICAL FAULT CALCULATIONS – PART – 13 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM 

For the network shown in the figure. If the fault occurs on the bus three, calculate the per-unit fault current when Xf = 0 and Xf = j0.15 and also calculate the current contribution of generator and motor.

SYMMETRICAL FAULT CALCULATIONS – PART – 12 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM

For the network shown in the figure. If the fault occurs on the bus three, calculate the per-unit fault current when Xf = 0 and Xf = j0.15.

SYMMETRICAL FAULT CALCULATIONS – PART – 11 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM

For the network shown in the figure. If the fault occurs on the bus two, calculate the per-unit fault current when Xf = 0 and Xf = j0.15 and also calculate the current contribution by the generators G1 and G2.

SYMMETRICAL FAULT CALCULATIONS – PART – 10 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM

For the network shown in the figure. If the fault occurs on the bus three, calculate the per-unit fault current and actual fault current.

SYMMETRICAL FAULT CALCULATIONS – PART – 09 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM

For the network shown in the figure. If the fault occurs in the mid of the transmission line calculate the per-unit fault current and actual fault current.

SYMMETRICAL FAULT CALCULATIONS – PART – 08 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM 

For the system shown in the figure.

Calculate the fault current and short circuit MVA if three-phase a balanced fault occurs at the LV and HV side of the transformer.

SYMMETRICAL FAULT CALCULATIONS – PART – 07 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM

For the system shown in the figure.

Calculate the fault current and short circuit MVA if three-phase a balanced fault occurs at the LV and HV side of the transformer. 

SYMMETRICAL FAULT CALCULATIONS – PART – 06 –APPLICATION OF THEVENIN’S THEOREM & ONE PROBLEM

PROBLEM

A 50 MVA, star connected 11kV synchronous generator is connected to a 50 MVA, 11 kV/132 kV , Delta/Star transformer, sub-transient reactance of the generator is 0.12 p.u on a 50 MVA base and the transformer reactance is 0.1 p.u reactance on the same base. The generator is unloaded when a symmetrical fault occurs at point A. Find the sub-transient symmetrical fault current on both sides of the transformer.

SYMMETRICAL FAULT CALCULATIONS – PART – 05 – CALCULATION OF FAULT CURRENT, BUS VOLTAGES AND CURRENTS & ONE PROBLEM

PROBLEM

The reactance diagram of the system shown in the figure. If a balanced three phase fault occurs at bus 2. Calculate the sub-transient current in p.u from generator 1 and in line 1-2 and bus voltages during the fault.