Determine the percentage overload

Assignment Help Electrical Engineering

Reference no: EM132653723

Question 1. For a Ydl transformer:
(a) draw the connection diagram
(b) show how the connections must be modified to allow parallel operation with a Yd 11 transformer
(c) draw a phasor diagram for the modified connection.

Question 2. In your own words, state the three essential and two highly desirable conditions which must be fulfilled for two 3-phase transformers to operate satisfactorily in parallel.
State briefly what you think may be the possible consequences of not complying with these conditions.

Question 3. (a) Two single-phase transformers have the following impedances referred to the secondary side.
Unit A rated 250 kVA (0.09 + j2.7) SZ
Unit B rated 400 kVA (0.04 + j1.6) S2
Determine the load taken by each machine as a percentage of its rating when they share a common load of 500 kVA at 0.73 p.f. lag.

(b) Transformer A is rated at 300 kVA with an impedance of (0.09+j0.18)Q
Transformer B is rated at 200 kVA with an impedance of (0.09 + j0.23)
If these transformers are connected in parallel to supply a common load, determine the percentage overload on B when A supplies its full load at p.f. 0.45 lag.

Question 4. From the operating chart shown in FIGURE 15 of lesson ESD - 2 - 2, determine the following performance limitations for a generator:
(a) where the power limit and the MVA limit coincide;
(i) the power factor
(ii) the load angle
(iii) the MVAr output
(b) where the power limit and the stability margin coincide;
(i) the p.u. excitation
(ii) the MVA output.

Question 5. A 3-phase synchronous generator rated at 570 MVA is connected to an infinite busbar. Using the data given in the table below, plot the capacity chart of the generator.

Quantity

Value

Synchronised Reactance Excitation Limit Maximum Margin Turbine Power Limit Stability Margin

2.0. p.u.

2.8 p.u.

570 MVA

500 MW

10% Full Load Power

Reference no: EM132653723

Questions Cloud

Make an outline of a plan of action : Make an outline of a plan of action that will elevate any city in Metro Manila among the leading global cities in the world. The plan must be divided into three

Discuss about the emerging treats and countermeasure : Penetration testing is a simulated cyberattack against a computer or network that checks for exploitable vulnerabilities. Pen tests can involve attempting.

Investment and savings and goods market equilibrium : Use the saving-investment diagram (graph) to analyze the effects of the following events on the national savings, investment, and interest rates and clearly lab

Price elasticity of supply for watches : A firm calculates the price elasticity of supply for watches using the dollar amount it charges per hundred watches (Price)

Determine the percentage overload : State briefly what you think may be the possible consequences of not complying with these conditions - determine the percentage overload on B when

Compute the fixed and variable cost elements using high-low : Daniel Office Supplies shows the following data related to shipping costs. Compute the fixed and variable cost elements using the high-low method.

Analyze effectiveness as you perceive in the organization : Do you think that ISO 27001 standard would work well in the organization that you currently or previously have worked for? If you are currently using ISO 27001.

Find what is the total cost of the job : What is the total cost of the job? If the engineer worked for 20 hours on a job. Z. the overhead rates were l25 per cent of direct Wood and the direct Wrote

Why the market can generate surplus and efficiency : You need a new table for your kitchen, you are willing to pay $400 for it. You aren't good with tools or wood working.

User Account

All Pages