QUESTION 3. (a) The positive-, negative- and zero-sequence reactances of a 20-MVA, 13.2-LV synchronous generator are...
The positive, negative and zero-sequence reactances of a 20-MVA, 13.2 kV synchronous generator are 0.3 pu, 0.2 pu, and 0.1 pu respectively. The generator is solidly grounded and is not loaded. If a double line-to-ground fault occurs at the generator terminals, calculate: (i) The fault current (ii) The line voltages (iii) Explain the steps that was carried out in the sequence voltage changes at all buses of the system. (Do include explanations and analysis of your solutions such as use...
3. A 200 MVA, 20 kV, 60 Hz Y-connected solidly grounded three phase synchronous generator connected through a 200 MVA 20/138 KV Y-Y transformer to a 138 kV transmission line. The generator reactances to the machine's own base are X-1.10 Both of the transformers Y connections are solidly grounded and its positive, negative and zero sequence series resitances are all 0.10 pu. a. What is the voltage at the terminals of the generator during the sub transient period if a...
4. A generator having a solidly grounded neutral and rated 50-MVA, 30-kV has positive, negative-, and zero-sequence reactances of 35, 25, and 5 percent, respectively (a) What reactance must be placed in the generator neutral to limit the fault current for a bolted line-to-ground fault to that for a bolted three-phase fault? (b) What reactance must be placed in the generator neutral to limit the fault current for a bolted double line-to-ground fault to that for a bolted three-phase fault?
A single line diagram of a power system is shown in Fig. 2. The system data with equipment ratings and assumed sequence reactances are given the following table. The neutrals of the generator and A-Y transformers are solidly grounded. The motor neutral is grounded through a reactance Xn 0.05 per unit on the motor base. Assume that Pre-fault voltage is takin as VF-1.0 ,0° per unit and Pre- fault load current and Δ-Y transformer phase shift are neglected In the...
A 50 Hz, 250 MVA synchronous generator having inertia constant H=5 MJ/MVA is connected to an infinite bus through transformer and transmission line as shown below. The transformer reactance is based on 500 MVA, while the other impedances are based on the generator MVA Infinite bus 1 2 3 XL 0.1 pu - oto G1 V= 1.0 pu X 0.1 pu Xd = 0.3 pu at 500 MVA The generator is delivering 0.8 of full load current at a power...
03 Consider the following one line diagram. The generator is rated at 25 MVA, IN has subtransient reactance of 20 %. The transmission line has a reactance of 10 The subtransient reactance of motorlis 0.345 pu where is that ol second more pu. Each motor has the following ratings. 10 MVA and 11 kV. Both transformers are rated at 25 MVA and have a reactance of 8.05% each; the transformers 1 and 2 have voltage ratio of 11/121 KV and...
can you calculating this question and explain why? thanks The ratings and sequence reactances of the components for the power system shown in Figure 2 are given in Table 1. The pre-fault voltage is 1/0° per unit (pu). Bus 8 L3 Bus 1 T1 Bus 4 T2 Bus 2 Bus 5 L1 L2 G1 Bus 3 T3 Bus 7 Bus 6 D.6975 Figure Draw the per unit impedance sequence networks and determine the per unit (a) Thevenin impedances of the...
I need help in matlab codes please Single line to ground fault analysis Example 9.4 Problem 1 A three-phase, il kV, 30 MVA alternator with grounded neutral has a direct axis subtransien pu respectively based on system base. A single line to ground fault has occurred in phase a. Determine the fault current, line to ground voltages in pu. t, negative sequence and zero sequence reactances of 0.2 pu, 0.3 pu and 0.1 Solution: Phase voltage E.0 pu From equation...
1. A three-phase synchronous generator connected to a 345-KV transmission line through a transformer as shown in Figure P1. Parameters of both generator and transformer are given in the figure. Transformer losses and exciting current are neglected. A three-phase short-circuit occurs on the line side of the circuit breaker when the generator is operated at rated terminal voltage and at no-load. The breaker interrupts the fault three cycles after fault inception. Neglect the effect of the transformer on the time...
Q3: (15 Points) Equi below are given as follows: pment ratings and per-unit reactances for the system shown in circuit 2 4 T1 TL12 T2b G1 G2 TL13 TL23 0.03 j0.03 Synchronous Generators: G1 100 MVA 25 kV G2 100 MVA 3.8 kV Transformers: T1 100 MVA 25/230 kV T2 100 MVA 13.8 /230 kV X1=X2= 0.2 X0-0.05 X1-X2-0.2 X0 0.05 X1 = X2-X0 = 0.05 Transmission lines: TL12 100 MVA TL13 100 MVA TL23 100 MVA X0 0.3 XO...