Figure 1 shows a power system which is connected to a 275 kV grid source. The...
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
Figure 1 shows a power system which is connected to a 275 kV grid source. The 275 kV voltage is step down to 132 kV to form a sub-transmission network with buses 2, 3, 4 and 5. A new substation with two units of 132/33 kV transformers are installed to step down the 132 kV voltage to 33 kV voltage as primary distribution. Network parameters of the power system on a 100 MVA base are given in Table 1. Three phase fault level at bus 1 is 3000 MVA. Table 1: Network Parameters of the Power System From Bus To Bus 1 2 2 3 4 5 2 3 4 5 5 6 Network Component 2 units of 275/132 kV transformers 20 km of 132 kV Line 9 km of 132 kV Line 17 km 132 kV Line 26 km of 132 kV Line 2 units of 132/33 kV transformers a) Determine the fault level in MVA at bus 2. Positive Sequence Impedance 0.02 per unit 0.02278 per unit/km 0.03743 per unit/km 0.0203 per unit/km 0.00108 per unit/km 0.163 per unit [5 marks] b) A three phase bolted balanced fault occur at a point 5 km away from bus 4 on the 132 kV line between bus 4 and bus 5 as shown in Figure 1. Determine the fault current in per unit flowing in the 132 kV line between bus 3 and bus 5. Assume pre-fault voltage at ALL buses is 1.0 per unit. c) Determine the voltage during fault at bus 2. [3 marks] d) As a consequence to the fault which occurred on the 132 kV line between bus 4 and bus 5, circuit breakers X45 and X54 were switched OFF. A three-phase balanced fault with fault impedance, XF = 0.2 per unit then occurs at bus 6, the 33 kV side of the 132/33 kV transformers. Determine the fault current in amperes flowing through the 132 kV circuit breakers of the 132/33 kV transformers. [6 marks] [7 marks] e) Assuming that ALL the 132 kV circuit breakers short circuit current are rated at 40 kA, explain whether it is safe or unsafe to operate the power system given in Figure 1. Bus 4 X42 5 km 3 ph fault Bus 2 X24 X45 X54 Bus 5 Figure 1 Bus 1 275/132 kV Transformer X23 X35 X53 Bus 3 132/33 kV Transformer Bus 6 Figure 1 shows a power system which is connected to a 275 kV grid source. The 275 kV voltage is step down to 132 kV to form a sub-transmission network with buses 2, 3, 4 and 5. A new substation with two units of 132/33 kV transformers are installed to step down the 132 kV voltage to 33 kV voltage as primary distribution. Network parameters of the power system on a 100 MVA base are given in Table 1. Three phase fault level at bus 1 is 3000 MVA. Table 1: Network Parameters of the Power System From Bus To Bus 1 2 2 3 4 5 2 3 4 5 5 6 Network Component 2 units of 275/132 kV transformers 20 km of 132 kV Line 9 km of 132 kV Line 17 km 132 kV Line 26 km of 132 kV Line 2 units of 132/33 kV transformers a) Determine the fault level in MVA at bus 2. Positive Sequence Impedance 0.02 per unit 0.02278 per unit/km 0.03743 per unit/km 0.0203 per unit/km 0.00108 per unit/km 0.163 per unit [5 marks] b) A three phase bolted balanced fault occur at a point 5 km away from bus 4 on the 132 kV line between bus 4 and bus 5 as shown in Figure 1. Determine the fault current in per unit flowing in the 132 kV line between bus 3 and bus 5. Assume pre-fault voltage at ALL buses is 1.0 per unit. c) Determine the voltage during fault at bus 2. [3 marks] d) As a consequence to the fault which occurred on the 132 kV line between bus 4 and bus 5, circuit breakers X45 and X54 were switched OFF. A three-phase balanced fault with fault impedance, XF = 0.2 per unit then occurs at bus 6, the 33 kV side of the 132/33 kV transformers. Determine the fault current in amperes flowing through the 132 kV circuit breakers of the 132/33 kV transformers. [6 marks] [7 marks] e) Assuming that ALL the 132 kV circuit breakers short circuit current are rated at 40 kA, explain whether it is safe or unsafe to operate the power system given in Figure 1. Bus 4 X42 5 km 3 ph fault Bus 2 X24 X45 X54 Bus 5 Figure 1 Bus 1 275/132 kV Transformer X23 X35 X53 Bus 3 132/33 kV Transformer Bus 6
Expert Answer:
Answer rating: 100% (QA)
Answer to question a To determine the fault level in MVA at bus 2we can use the following equation Fault level at bus 2 Fault level at bus 1 1 Impedance between bus 1 and bus 2 Step 1 Calculate the im... View the full answer
Related Book For
Auditing The Art And Science Of Assurance Engagements
ISBN: 9780136692089
15th Canadian Edition
Authors: Alvin A. Arens, Randal J. Elder, Mark S. Beasley, Chris E. Hogan, Joanne C. Jones
Posted Date:
Students also viewed these accounting questions
-
Managing Scope Changes Case Study Scope changes on a project can occur regardless of how well the project is planned or executed. Scope changes can be the result of something that was omitted during...
-
Write a paper about a travel e-business that specializes in planning golf vacations has plans to offer its trips to customers around the globe.
-
Figure 12.76 displays a three-phase delta-connected motor load which is connected to a line voltage of 440 V and draws 4 kVA at a power factor of 72 percent lagging. In addition, a single 1.8 kVAR...
-
A puck on a horizontal, frictionless surface is attached to a string that passes through a hole in the surface, as shown in FIGURE 11-52. As the puck rotates about the hole, the string is pulled...
-
Both iGAAP and U.S. GAAP require footnote disclosure of operating lease payments. Are there any differences in the information provided to statement readers in these disclosures? Explain.
-
A 10 000 lb aircraft has a (L/D)max value of 9.8; find its minimum drag.
-
How to interview clients?
-
Beginning inventory, purchases, and sales for WCS12 are as follows: Assuming a perpetual inventory system and using the weighted average method, determine (a) The weighted average unit cost after the...
-
Use limits involving to to describe the asymptotic behavior of the function from its graph. (If the limit is infinite, enter 'o' or '-', as appropriate. If the limit does not otherwise exist, enter...
-
You and a classmate are assigned a project on which you will receive one combined grade. You each want to receive a good grade, but you also want to avoid hard work. In particular, here is the...
-
A thermocouple produces an e.m.f. in mV according to the temperature difference between the sensor tip 0 and the gauge head 02 such that e = = a(0-0) + B(0 - 0). x= 3.5 x 10- (mV/K), = 8.2 x 10-6...
-
Approximately how much value was lost as a result of the WorldCom collapse?
-
What alternative courses of action, if any, might you have suggested for Cynthia Cooper and her colleagues given the framework of appropriate ethical conduct?
-
From an ethical perspective, did Cynthia Cooper have to report this fraud? Why or why not?
-
What ethical issues, conflicts of interest, and noncompliance with corporate policies and procedures might Cynthia Cooper have faced in the context of her investigation?
-
Do any accounting or payroll personnel or related parties appear on the contractor payroll?
-
To what extent (if at all) and in what ways can western theories of modernity and identity contribute to an understanding of the formation of youth identities in China? 2. How have ideals of...
-
Interest Compounded Annually. When P dollars is invested at interest rate i, compounded annually, for t years, the investment grows to A dollars, where A = P(1 + i) t . Trevor's parents deposit $7800...
-
Below are some key facts about Hillsburg Hardware and Ben & James, the paint manufacturer, Hillsburg is considering purchasing. Hillsburg Hardware Limited Hillsburg Stores Ltd. began operations in...
-
The following independent scenarios describe auditor decisions made during an audit engagement. 1. Chen Li worked on the audit of Diagnostic Imaging Services (DSI), which provides diagnostic imaging...
-
Archer Uniforms Inc. is a distributor of professional uniforms to retail stores that sell work clothing to professionals such as doctors, nurses, and security guards. Traditionally, most of the sales...
-
Use the data given in exercise SB-3. Assume that in November 2021, General Motors sold half its investment in \(\mathrm{ABC}\) to Toyota. The sale price was \(\$ 14\) million. Compute General...
-
Use the data given in exercise SB-1. On May 19, 2021, Knowlton sold its investment in BCE shares for \(\$ 26\) per share. 1. Journalize the sale. No explanation is required. 2. How does the gain or...
-
Arnold Financing leases airplanes to airline companies. Arnold has just signed a 10 -year lease agreement that requires annual lease payments of \(\$ 1,000,000\). What is the present value of the...
Study smarter with the SolutionInn App