Question

1. The bus bars of a power station are in two sections A and B separated...

1. The bus bars of a power station are in two sections A and B separated by a reactor. Connected in section A are two 12 MVA generators of 15% reactance each and to B, 8 MVA generator of reactance 10%. The reactor is rated 8 MVA and 15% reactance. Two feeders are connected to bus bar A through transformers, each rated at 4 MVA and 5% reactance. Determine the maximum short circuit MVA with which circuit breakers on the outgoing side of the transformers have to deal.

2.. A 15 MVA, 6.6 kV, wye connected generator has X1 = X2 = 20% and X0 = 10%. The neutral of the generator is grounded through a reactor of 5% reactance based on the generator rating. A double line-to-ground fault occurs at terminals b and c. What is the current in the ground?

0 0
Add a comment Improve this question Transcribed image text
Answer #1

As per HomeworkLib policy we need to answer only the first question if multiple questions are posted. Please upload remaining questions separately so that someone can answer. Please find below for the explanation of first question. Thanks in advance for understanding...

Add a comment
Know the answer?
Add Answer to:
1. The bus bars of a power station are in two sections A and B separated...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • 11.2 kV 11.2 kV Şoor Bus-1A 230 kV Bus-1B 230 kV CB св. Fig. 1 Fig....

    11.2 kV 11.2 kV Şoor Bus-1A 230 kV Bus-1B 230 kV CB св. Fig. 1 Fig. 1 shows a part of a power system having four synchronous generators. Generators G1 and G2 are rated at 11.2 kV, 60 MVA, and each have a sub-transient reactance of 15%. Generators G3 and G4 are rated at 11.2 kV, 50 MVA, and each have a sub-transient reactance of 20%. Transformers T, and T2 are both rated at 11.2 kV/230 kV, 120 MVA and...

  • Power System

     A simple three-phase power system is shown in Figure 2. Assume that the ratings of the various devices in this system are as follows: • Generators G1, G2: 40 MVA, 13.2 kV, = 0.15 pu, = 0.15 pu, = 0.08 • Generator G3: 60 MVA, 13.8 kV, = 0.20 pu, 0.20 pu, - 0.08 • Transformers T1, T2, T3, T4: 40 MVA, 13.8/138 kV, X1 = X2 = 0.10 pu, XO 0.08 pu Transformers T5, T6: 30 MVA, 13.8/138 kV, X1 = X2...

  • Note: # 1 states line to line fault occurs, while # 2 states double line to...

    Note: # 1 states line to line fault occurs, while # 2 states double line to ground fault occurs Please explain the solution thoroughly with diagrams The positive, negative, and zero sequence reactances of a 15-MVA, 11-kV, 3ph, wye-connected generator are 11%, 8% and 3%, respectively. The neutral of the generator is grounded, and the generator is excited to the rated voltage on open circuit. A line-to-line fault occurs between phases b and c of the generator while phase a...

  • 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...

    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...

  • 3. A 200 MVA, 20 kV, 60 Hz Y-connected solidly grounded three phase synchronous generator connect...

    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...

  • A 7-bus power system with three generators, six transformers, and seven transmission lines is shown in...

    A 7-bus power system with three generators, six transformers, and seven transmission lines is shown in Figure Q1. The per-unit reactances for the generators and transfomers are based on their rated voltage and expressed in percentage. When a three-phase fault occurs at bus 5; three transmission lines, namely L4, L5, and L6, are disconnected from the power system. By taking the base apparent power of 100 MVA and the rated voltage of generator G1 as the reference, determine the per-unit...

  • a five bus system

    The equipment ratings for a five bus system are given as Generator G1: 50 MVA, 12 kV, Xd ’’=X2=0.20, X0= 0.10 per unit Generator G2: 100 MVA, 15 kV, Xd ’’=0.2, X2=0.23, X0= 0.10 per unit Transformer T1: 50 MVA, 10 kV (Y)/138 kV (Y), X=0.10 per unit Transformer T1: 100 MVA, 15 kV (∆)/138 kV (Y), X=0.10 per unit Each 138 kV line: X1=40 Ohms, X0=100 ohms (1) Draw out the zero-, positive-, and negative- sequence reactance diagrams for the original system using a 100-MVA,...

  • The one-line diagram of a simple power system is shown in Figure 1. The neutral of...

    The one-line diagram of a simple power system is shown in Figure 1. The neutral of each generator is grounded through a current-limiting reactor of 0.25/3 per unit on a 100-MVA base. The system data expressed in per unit on a common 100-MVA base is tabulated below. The generators are running on no-load at their rated voltage and rated frequency with their emfs in phase. Determine the fault current for the following faults giving Zo = 0.35, Z = 0.22...

  • Assuming there is a FAULT at BUS 3, Determine the thevenin equivalent of each series network...

    Assuming there is a FAULT at BUS 3, Determine the thevenin equivalent of each series network as viewed from the fault bus. Given: -Prefault voltage is 1.0 per unit -Prefault load currents and delta-wye transformer phase shifts are neglected Synchronous generators G1 1000 MVA 15 kVX"-X2 0.18, Xo 0.07 per unit G2 1000 MVA 15 kV X: X, = 0.20, X,-0.10 per unit G3 500 MVA 13.8 kV X: X,-0.15, X,-0.05 per unit G4 750 MVA 13.8 kV X,-0.30, X,-0.40,...

  • Q3: (15 Points) Equi below are given as follows: pment ratings and per-unit reactances for the sy...

    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...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT